the Mississippi CDL Manual

the Mississippi CDL Manual
Commercial Driver’s islconse Manual
Commercial Driver’s License Manual
All skills test are done by appointment only, you may cali any CDL testing office to schedule an appointment.
Pre-test, off-road tests are included. If a test is failed, the applicant musi make another appointment. The
second appointment 3 * wiil be made depending upon the severity of the violations during the {esl procedure.
Third Party Testing
72 third party testers — 100% open to the public. 20% of totai tests are adminisiered by third party testers. Third
party testers’ fees not regulated by the State.
Schoo! Bus Test
Must pass General Knowiedge, Passenger Test and an S Endorsement Test must be completed/passed. Skill
Tesis anplicable to class of vehicle brought in for testing.
License Renewal
Every Four Years. Only “FH” endorsements require retesting.
CDL Learner's Permit
Must pass vision anc ciass-required written tests. Vaiic for six months. Only three renewals shall be granted
within a three-year period.
License Fees
Application fee Ne aa a aerrm ee $25.00
-Icense (4 Years)... TTTUN $41.00
a a aaaaL een o $ 5.00
CD. Learner's Permit.......... nea ae rarrarero. ea, $13.0C
Hazardous Materiais Background check.…………………… UT $100.00
Knowledge Test
Offices administering
Test content
Model test as authorized by Essex Corporation
Group Testing
3y appointment. Maximum 25 applicants.
Qut-of-State CDL Applicants
Present valid state's commercial driver license, Social Security Card, and proof of Mississippi residence.
Pay application fee, endorsement fees (if any), and license fees, If HazMat endorsement, will be required to re-
test and submit fingerprints for a federal background check. Mus: be accom plished within 30 days after
applicant has established residence in Mississippi.
#edical Requirements (Intrastate COL Applicants)
Adopted Part 391 of FMCSR.
Siate Provisions
Same Federal minimum
Method of Acjucication-Administrative/Crmina!
Commercial Driver's License Manua!
Ciass A - Any Combination of vehicies with a gross combination weight rating (GCWR) of
26,001 pounds or more, provided the gross vehicle weight rating (GVWR) of the venicle(S)
being towed is in excess of 10,000 pounds.
Ciass E: — Any Single vehicle with a gross vehicle weight rating of 26,001 pounds o; more,
Class C -- Any Single vehicie with a gross vehicle weight rating of iess than 26,001 pounds.
A. Vehicles designed to transport sixteen or more bassengers, including the driver.
R. Vehicles ised in the transportation of hazardous materials which are reouired to be piacarded
under the Hazardous Materials Transportation Act.
H — Autho:izes the driver to drive a vehicie transporting Hazardous Materials
« — Restricts the driver to vehicles not eq uipped with air biakes
T — Authorizes driving doubles and triple trailers
P — Authorizes driving vehicles carrying passengers
Ww -- Authorizes driving Tank vehicles
X — Represents 2 combination of nazardous materials and tani vehicles endorsements
3 — Authorizes the driver to schoo; buses being operated for the purpose of transporting pupils to
and from school or to school relatec functions.
Commercial Driver's License Manual
District — 1 District — 2 District — 3
Troop C — Rankin County Greenville Nesbit
3158 Highway 468 420 Highway 82 West 159 License Drive
Pearl, MS 39208 Greenville, MS 38701 Nesbit, MS 38651
(601) 420-6342 (662) 332-4734 (562) 429-5584
District — 4 District — 5 District — 6
New Albany Columbus-Lowndes Newton
1103 Bratton Road 17 Airline Road 923 Coliseum Drive
New Albany, MS 38652 Lowndes, MS 39701 Newton, MS 39345
(662) 534-8619 (662) 327-1833 (601) 683-2576
1879 North Coley Road
Tupelo, MS 38801
(661) 844-2408
District — 7 District — 8 District — 9
Hattiesburg Bay Saint Louis Brookhaven
35 Tatum Drive 3016 Longfellow Road 160 Highway 84 East
Hattiesburg, MS 39401 Bay Saint Louis, MS 39520 Brookhaven, MS 39601
(601)582-3814 (228)467-8055 (601)8330808
724 Highway 61 North
Natchez, MS 39120
(601) 442-4879
There is no set time limit for taking the written test.
To schedule a road Test go to WWW,
Commercial Driver's License Manual
Federal Motor Carrier Regulations
Subpart D — Driver Disqualifications and Penalties
§383.51 Disqualification of drivers.
(a) General. (1) A driver or hoider of a CDL who is disqualified must not drive a CMV.
(al2) An employer must not knowin
a CMV.
(a)(3) À driver is subject to disqualification sanctio
the hoider of a CDL drives a CMV or non
(aX4) Determining first and subsequent violations. For
gly allow, require, permit, or authorize a driver who is disqualified to drive
ns designated in paragraphs (b) and (c) of this section, If
-CMV and is convicted of the violations.
purposes of determining first and subsequent
violations of the offenses specified in this subpart, each conviction for any offense listed in Tables 1 through 4
to this section resulting from a separate incident, whether com
{a)(5) Reinstatement after lifetime dis
offenses described In paragraphs (b)
that person has voluntarily entered and successfully completed an appropriate
approved by the State. Any person who has been reinstated in accordance wi
subsequently convicted of a disqualifying offense described in
(Table 1 to §383.51) must not be reinstated.
(b) Disqualification for major offenses. Table 1 to
for which a driver must be disqualified, depending upon
of the violation, as follows:
(1) through (bY(8) of this section (Table 1 to
mitted in a CMV or nen-CMV, must be counted.
qualification. A State may reinstate any driver disqualified for life for
§383.51) after 10 years if
rehabilitation program
th this provision and who is
paragraphs (b)(1) through (b)(8) of this section
3383.51 contains a list of the offenses and periods
the type of vehicle the driver is operating at the time
Table 1 to $383.51
For a first For a first conviction or For a second
conviction or For a first refusal to be tested while | conviction or refusal
refusal to be conviction or operating a CMV to ba tested In a
tested while refusal to be transporting hazardous separate incident of Рога second conviction or
| operating a tested while Materials required tobe | any combination of refusal to be tested in a
If a driver CMV, a person | operating a placarded under the offenses in this Table | separate incident of any
operates a motor required to have | non-CMV a Hazardous Materials while operating a combination of offenses in
vehicle and is a COL and a CDL h older Regulations (49 CFR CMV, a person this Table while operating a
convicted of CDL holder must ba part 172, subpart F), a required to have a non-CMV, a CDL holder
must be disqualified person required to have | CDL and a CDL must be disqualified from
disqualified from | from operating | 2 GDL and CDL holder holder must be operating a CMV for...
operating a a CMV for... must be disqualified disqualified from
CMV for... pom operating a CMV operating а СМУ
Г... Г...
{1) Being under 1 year 1 year 3 years Life Life
the influence of
alcohol as
prescribed by
State law. a. I
(2) Being under 1 year 1 year 3 years Life Life
the influence of a
(3) Having an
0.04 or greater г || 1 уваг 1 year 3 years Life Life
while operating a
CMV _ nn
(4) Refusing fo 1 year 1 year 3 years Life Life
take an alcohol
test as required
by a State or
_ jurisdiction under
Commercial Driver's License Manual
its implied
consent laws or
reguiations as
defined in
§383.72 of this
(5) Leaving the
scene of an
1 year 1 year
3 years
(6) Using the
vehicle to commit
a felony other
than a felony
described in
paragraph (b)(9)
of this table.
1 year 1 year
3 years
(7) Driving a
CMV when, as a
result of prior
operating a CMV,
the drivers CDL
is revoked,
suspended, or
canceled, or the
driver is
disqualified from
_ operating a CMV.
1 year
Not applicable
3 years
Not applicable
(8) Causing a
fatality through
the negligent
operation of a
CMV, including
but not limited to
the crimes of
motor vehicle
homicide by
motor vehicle
and negligent
1 year
Not applicable
3 years
Not applicable
(9) Using the
vehicie in the
commission of à
felony involving
distributing, or
dispensing a
Life-not eligible
for 10-year
for 10-year
Life-rot eligible
year reinstatement,
Life-not eligible for 10-
Life-nof eligible for
Life-not eligible for 10-year
I Disqualification for serious traffic violations. Table 2 to $383.51
periods for which a driver must be disqualified, depending upon the type of vehicle the driver is operating at the time of
the violation, as follows:
contains a list of the offenses and the
Table 2 to $383.51
For a second conviction | For a second conviction | Fora third or For a thind or subsequent
of any combination of of any combination of subsequent conviction of any
offenses in this Tablein | offenses in this Tablein | conviction of any combination of offenses in
a separate incident a separate incident combination of th's Table in a separate
If à driver operates a within a 3-year period within a 3-year period offenses in this incident within a 3-year
motor vehicle and is while operating a CMV, while operating a non- Table in a separate | period while operating a
convicted of: a person required to CMV, a CDL holder incident within a 3- | non-CMV, a CDL holder
have a COL anda CDL | must be disqualified year period while must be disqualified from
holder must be from operating a CMV, if | operati nga CMV, a | operating a CMV, if the
disqualified from the conviction results in | person required to conviction results in the
operating a CMV for... the revocation, ¡ havea COL anda | revocation, cancellation, or |
Commercial Driver's License Manual
cancellation, or
suspension of the COL
holder's license or non-
CMV driving privileges,
CDL holder must
be disqualified from
operating a CMV
suspension of the CDL
holder's license or non-
CMV driving privileges,
(1) Speeding
excessively, involving
| or more above tha
any speed of 15 mph
posted speed limit,
680 days
60 days
120 days
120 days
(2) Driving recklessly,
as defined by State or
local law or regulation,
including but not limited
to, offenses of driving a
motor vehicle in willful
or wanton disregard for
the safety of persons or
| Property.
60 days
60 days
120 days
120 days
(3) Making improper or
erratic traffic lane
60 days
60 days
120 days
120 days
(4) Following the
vehicle ahead too
60 days
60 days
120 days
120 days
(5) Violating State or
local law relating to
motor vehicle traffic
control (other than a
parking violation)
arising In connection
with a fatal accident.
80 days
60 days
120 days
120 days
(6) Driving a CMV
without obtaining a
Not applicable
120 days
Not applicable
(7) Driving a CMV
without à CDL In the
drivers possession.‘
Not applicable
120 days
Not applicable
1 without the proper class
(8) Driving a CMV
of CDI. and/or
endorsements for the
specific vehicle group
being operated or far
the passengers or type
of cargo being
Not applicable
120 days
Not applicable |
transported. _…
" Any individual who provides proof to the enforceme
individual must appear in court or pay any fine for su
date the citation was Issued, shall not be guilty of this offense.
(d) Disqualification for railroa
list of the offenses and the period
at the time of the violation, as follows:
Table 3 to §383.51
nt authority that issued the citation, by the date the
ch a violation, that the individual held a valid CDL on the
d-highway grade crossing offenses. Table 3 to 8383.51 contains a
s for which a driver must be disqualified, when the driver is operating a CMV
i if a driver is convicted of
For à first conviction a
For à second conviction of any
combination of offenses in this Table
For a third or subsequent conviction of
any tombination of offenses in this
of an approaching train.
i operating a CMV in E CDL anda COL holder iN 3 separate incident within a 3-year | Table in a separate incident within a
| violation of a Federal, must be disqualified period a person required to have a 3-year period a person required to
State or local law from operating a CMV CDL and a CDL holder must be have a CDL and a CDL holder must
because... for disqualified from operating a CMV be disqualified from operating a CMV
Le for... for...
(1) me uns is ton No less than 60 days No less than 120 days No less than 1 year.
requi always ,
but fails to stow down and
check that tracks are clear
Commercial Driver's License Manual
(2) The driver Is not No less than 60 days No less thar 120 days No less than 1 year. |
required to always stop,
but fails to stop before
reaching the crossing, if
the tracks are not clear.
(3) The driver is always No less than 60 days No less than 120 days No less than 1 year,
required to stop, but falis to
stop before driving onto
the crossing.
(4) The driver falls to have | No less than 60 days No less than 120 days Na less than 1 year,
sufficient space to drive
completely through the
crossing without stopping.
(5) The driver fails to abey | No less than 60 days No less than 120 days No less than 1 year.
a traffic contral device or
the directions of an
enforcement official at the
crossing. _
(6) The driver fails to No less than 80 days No less than 120 days No less than 1 vear,
negotiate a crossing
because of insufficient
| undercarriage clearance.
(e) Disqualification for violating out-of-service orders. Table 4 to 3363.51 contains a list of the
offenses and periods for which a driver must be disqualified when the driver is operating a CMV at the time of
the violation, as follows:
Table 4 to § 383.51
For a second conviction in a For a third or subsequent
whi eres eN а | Separate incident within a 10- | Ронни а 3 10-vear period
If à driver operates a CMV and is person required to have CMV a parao od 4 | while operating a СММ, а
Polos où must be squad from | ve CL and a СОК помет | Реп required to have à CDL
operating a CMV for... fiat Si ce Pe from disqualified from operating a
operating = CMV for...
(1) Violating a driver or vehicle out-of No less than 180 days No less than 2 years No less than 3 years.
service order while transporting
nonhazardous materials,
(2) Violating a driver or vehicle out-of- No less than 180 days, No less than 3 years. No less than 5 years.
service order while fransporting
hazardous materials required to be
placarded under part 172, subpart F of
| this title, or while operating a vehicle
designed to transport 16 or more
passengers, Including the driver. |
Commercial Driver's License Manual
Tabie Of Contents
Introduction AD 1-1
Driving Safely... en 0 2-1
Transporting Cargo Safely... 3-1
Transporting Passengers SafelYy 4-1
AIF Brakes... st an Aa 5-1
Gombination Vehicles 6-1
Doubles and Triples... „то
Tank Vehicles... аа 8-1
Hazardous Materials... 9-1
SCNOOÏ BUS... a AA 10-1
Pre-Trip Vehicle Inspection. 11-1
Basic Vehicle Control Skills Test... 12-1
Commercial Driver's License Manual
¢ Commercial Driver License Tests
« Driver Disqualifications
+ Diner Safety Rules
There is a federal requirement that each state have
minimum standards for the licensing of commercial
This manual provides driver license testing
information for drivers who wish to have a
commercial driver license (CD:). This manuz! does
MOT provide information on all the federal and
state requirements needed before you can drive a
commercial motor vehicle (CMV). You may have to
contact your state driver licensing authority for
acditional information,
You mus: have a CDI. to operate:
Any single vehicie vith a gross vehicle weight
rating (GVWR) of 26,001 pounds or more.
A trailer with a GVWR of more than 10,000 pounds
if the gross combination weight rating (GCWR) is
26,001 pounds or more.
A vehicle designed to transport 16 or more
passengers (including the driver).
Any size vehicle that is used in the transportation
of any material that requires hazardous materials
placards or any quantity of a material listed as a
select agent or toxin in 42 CFR 73. Federal
regulations through the Department of Homeland
Security require a Background check and
fingerprinting for the Hazardous Materials
endorsement. Contact your loca: department of
driver t'censing for more information.
(Your state may have additional definitions of
Ct М5.)
To get à CDL, you must pass knovdedge and skills
tests. rhis manus! will help you pass the tests.
This manual is not a substitute for a truck criver
traning cless oi program. Formal training is the
most reliable way to learn the many special skills
required for safely driving a large commercial
vehicle and becoming a professional driver in the
trucking industry
Figure 1.1 helps you cetermi-e if you need a CD.
Do You Need a COL?
Does the vehicle or
combination of venicles
have a manufacturer's
weight rating (GVWR)
over 25,000 pounds?
15 the
vesicle a —
combination You
vehicle Yes | needa
towing a unit Class A
over 10,000 COL,
pounds -
Does the You
single YS of needa
vehicie have Cass B
over 26.000
is the
vehicie You
designed to Mes needs
carry 16 or bi Cizss C
more people CEL,
the driver)?
J чо
Does the You
vehicle Yes | needa
require mm (lass C
hazardous Co.
р:2сагев or
transport a
select agen?
or toxin?
read a CD.
rigure 7
A bus may be Ciass А, B, o; C deponcing on whatho:
the GVWR is over 26,001 pourds or ís a contados
Section 1 - 'ntrod.ction
Pege i-*
Commercial Drive="s License Manual
1.1 - Commercial Driver License Tesis
2.1.7 — Knowledge Tests
You vill have to take one or more knowedge tests,
depending on what class of license and what
endorsements you need. The CDL knowledge
tests include:
the genera. knowledge test, taken by al
(he passenger transport test, taken by all bus
driver anplicants.
The air brakes test, which you must take if your
venicie has air brakes, including air over hydraulic
Tie combination vehicles test, which is required if
you want to drive combination vehicles.
Tne hazardous materials test, required if you want
to haul hazardous materials or waste in amounts
that require placarding or any quantity of a material
listed as a select agent or toxin in 42 CFR 73. In
order to obtain this endorsement you are also
required to pass a Transportation Security
Administration (TSA) background check.
The tanker test, required if you want to haul a liquid
or liquid gas in a permarently mounted cargo tank
rated at 119 gallons or more or a portable tank
rated at 1,000 gallons or more.
The coublesftriples tesi, required if you want to pull
doub’e ог Ир! Кайе: с.
The Schooi Bust test, required if you want to drive
a school bus.
1.1,2 — Skills Tests
If you pass the required knowledge iest(s), you can
lake the CD: skils tests. There are three types of
general skills that will oe tested: pre-trip inspection,
basic vehicle control, and on-roaú driving. You
must take these tests in the type of vehicle for
which vou wis" to be licensed.
Pre-trip Vehicle Inspection. You will be tested to
see if you Know whether you; vehicle is safe to
drive. You will ba asked to do a pre-trip inspecion
of your vehicle and explain to the examiner wha:
you would inspect ard why.
Basic Vehicle Coniroi, You will be tested on your
Skill to contro! the vehicle. You will be asked to
move your vehic.e forward, backward, and turn it
within a defined area. These areas may be marked
with treff'c ‘anes, cores, barriers, or scmeihing
similar. The examiner will tell you now each control
test is to be done.
Cn-road Test, You wilr be tested on your siiil to
safely drive your vehicie in a variety of traffic
situations. The situations may inciude left and right
wrns, intersections, railroad crossings, curves, up
and down grades, single or multi-lane roads,
sireets, or highways. The examiner wil te!i you
where to drive.
Figure 1.2 details which sections of this manual
you should study for each particular class of
license and for each endorsement.
LT E TE E ry yo i ey
ATA OR ia Не E à я vale Ve
ве | в БВ) © | ® STO:
a | |S|ESIE|IO 9
ato =< _
I> 7 Oo E © & оо
“| =! | 6 | ® |5
© O
D th
$ X Ix |x
213 Ix [x Ix X [X IX |X
4 x |x |x |x
) |
5 FX x fx X X |x
6 |x X
7 X
8 X
9 X
10 X
11x IX |x |x x |x
121X |x |x [x X |X
13 1х Ix |x |x X IX
“Study section 5 if you plan to operate vehicles
equipped with air brakes.
Figure 1,2
Seciion 1 - Introduction
Page 7-2
Commercial Drivers License Nanua;
1.2 -- Driver Disqualifications
7.2.1 — Genera!
You may not drive a commercial motor vehicle if
you are disquaiified for any reason.
1.2.2 ~ Alcohal, Leaving the Scere of an
Accident, and Commission of a Felony
It is iliegal to operate a CHV if your blood alcohol
concentration (ВАС) № .04% or more. if you
operate a CMV, you shall be deemed to have
given your consent to alcohol testing.
You will lose your CDL for at least one year for 2
first offense for:
Driving a CMV if your blood alcoho! concentration
is .04% or higher.
Driving a CMV under the influence of alcohol.
Refusing to undergo blood alcohol testing.
Driving a CMV while under the influence of a
controlled substance.
Leaving the scene of an accident involving a CMV.
Commiiling a felony involving the use of a CHV.
You will lose your COL for at least three years if
the offense occurs while you are operating a CMV
that is placarded for hazardous materials.
You will lose your COL for life for a second offense.
You wili lose your CD!. for life ¡f you use a CMV to
commit a fe.onv involving controlled suhstances,
You will be put out-of-service for 24 hours if you
have any detectable amount of alcohol under
1.2.3 — Serious Trafiic Violatiorns
Serious traffic violatiors are excessive speeding
(15 mph or more above фе posted limit), reckless
driving, improper or erratic lane changes, following
a vehicle too closely, ard traffic offenses
committed in a CMV in connection with fatal traffic
You will lose your COL:
For at least 60 cays f vou have committed two
serious traffic violations within a three-vear period
involving a CMV.
For al east 120 Gays for three serious treffic
violations within a three-year period irvoiving a
1.2.4 — Violation, of Out-oi-Service Orders
You will iose your CDL:
-or at least 90 davs if you have committed your
first violation of an out-of-service violation order.
For at least one year i“ you have committed two
cut-of-service vioiation: orders in a ten-year period.
For at least three years if you have committed
thr22 or more out-of-service violation orders in a
ten-year oeriod.
1.2.9 -- Railroahighwar Grade Crossing
You will lose your CDI:
ror at least 60 days for your first violation.
For at least 120 days for your second violation
within any three-year period.
For at ieast ore year for your third violation within
any three-year period.
These violations include violation of a federal. state
or local law or regulation pertaining to one of the
foliowing six offerses at = railroac-highv:ay grade
For drivers who are not required to always siop,
“ailing tc stop before reaching the crossing If the
tracks are not clear.
For drivers who are not reguired to always stop,
failing to slow down and check that the tracks are
clear of an approaching train.
For drivers who are always required to stop, failing
to siop before driving onto the crossing.
For ad drivers failing to have sufficient space to
drive completely through the crossing without
For all drivers failing to obey a traffic control device
or the directions of an enforcement official at the
For afi drivers failing to negotiate a Crossing
because of insufficient undercarriage clearance.
1.2.5 -- Hazardous Materials Endorsement
Background Check and Disqualifications
If you require a hazardous materials endorsement
you will be required to submit your fingerprints and
be subject to a background check.
You will be danied or you will lose your hazardous
materials endorsement if you:
Are not á avful permanent resident of the Uritec
Renource youi United States ciiizenship.
Are wanted or under indictment for certain felonies.
Seciion 1 - fifrocucton
Page 1-3
Commercial Driver's _izense Manua!
Have a conviction in military or civilian court for
certain felonies.
Have been adjudicated as a mental defective or
committed to a mental institution.
Are considered to pose a security threat as
determined by the Transportation Security
The background check procedures vary from
jurisciction to ¡urisdiction. Your licensing agency
will provide you with all the information you neer' to
complate the required TSA background check
1.2.7 — Trafic Violations in Your Personal
“he Motor Carrier Safety Improvement Ас!
(MCSIA) of 1999 requires a CDL holder to be
disquaiiied from operating a commercial motor
vehicle if the CIL holder has been convicted of
certain types of moving violations in their personal
If your license (0 operate your personal vehicle is
revoked, cancelled, or suspended cue to serious
speeding violations you will lose your COL for
periods ranging from 60 to 120 days.
If your license to operate your personal vehicle is
revoked, cancelled, or suspanded due to alcohol
violations, you will lose your CDL for 1 year. If you
are convicted of a second alcohol conviction in
your personal venicle you will lose your CDL for
If your license to operate your personal vehicle is
revoked, cancelled, or suspended you may not
obtain a “hardship” license to operate a CMV.
1.2 - Other COL Rules
There are other federal and state rules that affect
drivers operating CMVs in all states. Among them
You cannot have more than one license. !f you
break this rule, a court may fine you up to 55,000
or nut you In jail and keep your home state ¡icense
and return any others,
You must notify your employer within 30 days of
conviction for any trafic violations (except parking).
This is true no matter what tyne of vehicle you
were driving.
You must noify your motor vehicle licensing
agency within 30 days if you are convicted in any
other jurisdiction of any traffic violation (excep:
parking). This is true no matler what type of vehic'e
you were úriving.
You must notify your employer if your license is
suspended, revoked, or canceled, or if you are
discuaiified from driving.
You must give your employer information or ai
uriving jobs you have held for the past 10 years.
You must do this when you apply for a commercie
driving job.
No ons can crive a commercial motor vehicle
without a CD... A court may fine vou up to $5,000
ar put you in jail for breaking this rule.
if you have a hazardous materials endorsement
you must notify and surrender your hazardous
materials endorsement to the state that issved
your CDL within 24 hours of ary conviction or
indictment in any jurisdiction, civilian or miliary, for,
or found not guilty by reason of insanity of a
disqualifying crime listed in ¿9 CFR 1572.103: who
is adjudicated es a mertal defective or committed
to a mental instiuion as specified in 49 CER
‘572.109; or who renounces his or her U. S.
You: employer may not let you drive a commercial
motor vehicle E you have more than one license or
if you're COL Is suspended or revoked. A court
may fine the employer up to $5,000 or put him/her
in jail “or breaking *his rue.
All states are connected to one computerized
system to snare information about CDL drivers.
¡he states will check on drivers' accident records
to de sure ihat drivers do not have mors than one
Your state may have additional rules that you must
also obey.
Section 1 -introcu tion
Commercial Driver’s License Manual
Tie Section Covers
Voñicle Inspection
« Basic Control of Your Vehicle
» Shifting Gears
+ Communicating
= Space Management
Controlling Your Speed
« Seeing Harards
« Diswacted Driving
+ Aggressive Drivers/Ruad Rage
«wight Driving
= Driving in Fog
s inter Driving
> Hot Weather Driving
« Railroad-highway Crossings
+ Mountain Driving
« driving Emergencies
= Andlock Bigking Systems
- Skid Coniroi anú Recovery
в Accident “rocedures
e Fires
» Alcohol, Cther Drugs, and Driving
» Staying Alert and Fit to Drive
© HKaxzardous Materiale Rules
This section contains knowledge and safe driving
information that al! commercial drivers should
know. You must pass a test on this information to
get a CDL. his section does not have specific
information on air brakes, combination vehicles.
doubles, or passenger vehicles. When preparing
for the Pre-t-ip Inspection Test, you must review
the material in Section 11 ín addition to the
information in this section. This section does have
basic information on hazardous materials (HazMat)
hat all drivers should know. If you need a HazMat
endorsement, you should stucy Section 9.
4.1 — Yehicle inspection
2.7.1 «— Why Inspect
Safety is the most important reason you inspect
your vehicle, safety for yourself and for other road
A vehicle defect found durirg an inspection could
save you problems later, You could have a
breakdown on the road that wil cost time and
dollars, or even worse, a crash caused by the
Federal and staie laws require that drivers inspect
heir vehicles. Federal and state inspectors also
may inspect your vehicies. If they judge tha vehicle
to be unsafe, they will put it “out of service” unt? it
is fixed.
2.1.2 ~ Types of Vehicle Insnaction
Pre-trip Inspection. A pre-trip inspection will help
you find problems that could czuse a crash or
During a Trip. For safety you should:
Watch gauges for sigrs of trouble.
Use your senses la check for problems (look,
listen, smell, feel).
Check critical items when you stop:
Tires, wheels and rims.
Lights and reflectors.
Brake and elecirical connections to trailer.
Trailer coupling devices.
Cargo securement devices.
After-trip inspection and Repo:t. You should do
an after-trip inspection at the end of tre trip, day, oi
tour of duty on each vehicle you operated. ‘t may
include rilling out a vehicle condition report listing
any problems you find. The inspection report helps
a motor carrier know when the vehicle needs
Section 2 — Dnv'rg Sate:y
Commercial Drivers License Manual
2.1.3 — What to Look For
Tire Problems
Too much or too little air pressure.
Bad wear. You need at least 4/32-inch fread depth
in every major groove on front tires. You need 2/32
inch on other tires. No fabric should show through
the tread or sidewall.
Cuts or other damage.
Tread separation.
Dual tires that come in contact with each other or
parts of the vehicle.
Mismatched sizes.
Radial and bias-ply tires used together.
Cut or cracked valve stems.
Regrooved, recapped, or retreaded tires on the
front wheels of a bus. These are prohibited.
Wheel and Rim Problems
Damaged rims.
Rust around wheel nuts may mean the nuts are
loose—check tightness, After a tire has been
changed, stop a short while later and re-check
tightness of nuts.
Missing clamps, spacers, studs, or lugs means
Mismatched, bent, or cracked lock rings are
Wheels or rims that have had welding repairs are
not safe.
Bad Brake Drums or Shoes
Cracked drums.
Shoes or pads with oil, grease, or brake fluid on
Shoes worn dangerously thin, missing, or broken.
Steering System Defects
Missing nuts, bolts, cotter keys, or cther parts.
Bent, loose, or broken parts, such as steering
column, steering gear box, or tie rods.
if power steering equipped, check hoses, pumps,
and fluid level; check for leaks.
Steering wheel play of more than 10 degrees
(approximately 2 inches movement at the rim of a
20-inch steering wheel) can make it hard to steer,
Figure 2.1 illustrates a typical steering system.
Suspension System Defects. The suspension
system holds up the vehicle and its load. It keeps
the axtes in place. Therefore, broken suspension
parts can be extremely dangerous. Look for:
Spring hangers that allow movement of axle from
proper position, See Figure 2.2.
Cracked or broken spring hangers.
Missing or broken leaves in any leaf spring. If one-
fourth or more are missing, it will put the vehicle
‘out of service, but any defect could be
dangerous. See Figure 2.3.
Broken leaves in a multi-leaf spring or leaves that
have shifted so they might hit a tire or other part.
Leaking shock absorbers.
Torque rod or arm, u-bolts, spring hangers, or
other axle positioning parts that are cracked,
damaged, or missing.
Air suspension systems that are damaged and/or
leaking. See Figure 2.4.
Any loose, cracked, broken, or missing frame
Steering Wheel
E Dra |
Gear Box of В 7
Pitman Spindle
Sh steering Knuckle P
Figure 2.1
Section 2 — Driving Safely
Page 2-2
Commercial Driver's License Manual
Hydraulic Shack Absorber
_ > Ta
i} +
Front Axle Hanger
Frame у в
ve re fe marre |
> A A Auxiliary Spring €.
| 3 а E E al 4 mE Mo ia
ll J
Eo \ :
; a va :
mcm ET
Vehicle Frama |
» $ Shackle
als Rod д
Figure 2.2
FR hd Main Spring
Figure 2.3
Height Control Valve Shock Absorber
Frame Reinforcement | Upper Bellows Support pacer
LY Ко, e , EN
( 3 E gh i Ca A A à я
wx ER : UE E pa 5,
Bracke? у BE oe "a e Balio:;s
Eye Bo A a] À
Control y Axl: # {
\ Loge Bellows
AM Author Ale Seat Support
Figure 2.4
Exhaust System Defects. A broken exhaust
system can let poison fumes into the cab or
sleeper berth. Look for:
Loose, broken, or missing exhaust pipes, mufflers,
tailpipes, or vertical stacks.
Loose, broken, or missing mounting brackets,
clamps, bolts, or nuts.
Exhaust system parts rubbing against fuel system
parts, tires, or other moving parts of vehicle.
Exhaust system parts that are leaking.
Emergency Equipment. Vehicles must be
equipped with emergency equipment. Look for:
Fire extinguisher(s).
Spare electrical fuses (unless equipped with circuit
Warning devices for parked vehicles (for example,
three reflective warning triangles).
Cargo (Trucks). You must make sure the truck is
not overloaded and the cargo is balanced and
secured before each trip. If the cargo contains
hazardous materials, you must inspect for proper
papers and placarding.
2.1.4 — CDL Pre-trip Vehicle Inspection Test
In order to obtain a CDL you will be required to
pass a pre-trip vehicle inspection test. You will be
tested to see if you know whether your vehicle is
safe to drive, You wilf be asked to do a pre-trip
inspection of your vehicle and explain to the
examiner what you would inspect and why. The
following seven-step inspection method should be
Section 2 — Driving Safely
Page 2-3
Commercial driver's License Manual
2.1.5 — Sever-sten inspection Method
weihod of inspection. You should do a pre-trip
inspection the same way each time so you will
earn all the steps and be less likely to forget
Lpproaching the Vehicle, Notice general
condition. Look for damage or vehicle leaning to
one side. Look under the vehicle for fresh oil
coolant, grease, or ue’ ‘caks. Check the area
around the vehicle for hazards to vehicle
movement (people, other vehicles, objects, iow-
hanging wires, limbs, etc.).
Vehicle Inspection Guide
Step i: Vehicle Qverview
Review Last Vehicle Inspection Report. Drivers
may have 10 make a vehicie inspection report in
writing each day. The motor carrier must repair any
tens in the report that affect safety and certify on
the report that repairs were made or were
unnecessary. You must sign the repori only if
defects were noted and certified (0 be repaired or
not neeced to be repaired.
Step 2: Check Engine Compartment
Check That the Perking Brakes Are On and/or
VVhoe!s Chockea. You may have to raise the
hood, tilt the cab (secure loose things so they don't
fall and break something), or open the engine
compartment door. Check the foliowing:
Engine oil level,
Coolant level in radiator; condition of hoses.
Power steering fluid level; hose condition (if so
Windshield viasher fluid (evel.
Battery fluid level, connections, and tie downs
(vatlery may be located eisewhere).
Automatic transmission fiuid level (may require to be running).
Check bells for tightness and excessive wear
(aternator, water pump, air compressor)-learn
how much “give the belts should have when
adiusted right, and check each one.
Leaks in the engine compartment (fuel, coolant oil,
povser steering fluid, hydraulic vid, battery fluid).
Cracked, worn electrical wiring insulation.
.Qwer and sacure hood, cab, or ergine
compartment door.
Siep 2: Start Engine and inspec: irsice the Jap
Go: In and Start Engine
Make sure parking brake is on.
Put gearshift 'n neutral (or “park” if automatic).
Start engine; listen for unusual noises.
if equipped, check the Anti-lock Braking Sysiem
(ABS) indicator lights. Light on desh should come
or and then turn off. if it stays on the ABS is not
working propeily. For trailers only, if the vel ow
ight on the left rear of the trailer stays on, the ABS
is not working properly.
=00K at the Gauges
Oil pressure. Should come up to normal within
seconds after engine is started. See Figure 2.5
Air pressure. Pressure shouid build from 50 ¡o 90
psi within 3 minutes. Build air pressure to governor
cut-out (usually around 120 — 140 psi. Know your
venicles requirements,
Ammeter and/or voltmeter. Should be in normal
Coolant temperature. Should begin gradual rise to
normal operating range.
chgine où temperature. Should begin gradual rise
to normal operating range.
Warning lights and buzzers. Qil, coolant, charging
circuit warning, and antiock brake system lights
should go out right away.
Check Condition of Controis. Check all of the
following for looseness, sticking, damage, or
improper setting:
Steering wheel.
Accelerator ("gas pedal”).
brake controis.
» root brake.
Trailer brake (if vehicle has one),
+ Parking orexe.
7 Retarder controls (if vehicle has them).
Transmission controls.
Interaxle differential lock (if vehicle has one),
Windshield wiper/vasher,
+ headlights,
= Dimmer switch.
7“ Turn signal.
= Four-way asiners.
» Parking, clearance, identification, marker
Section 2 - Diving Safely
Page 2-4
Commercial Driver's License Manual
* [dling 5-20 PSI
“Operating 35-75 PSI
+ Low, Dropping, Fluctuating:
Without oil the engine can be
destroyed rapidly
Figure 2.5
Check Mirrors and Windshield. inspect mirrors
and windshield for cracks, dirt, illegal stickers, or
other obstructions to seeing clearly. Clean and
adjust as necessary.
Check Emergency Equipment
Check for safety equipment:
> Spare electrical fuses (unless vehicle has
circuit breakers).
» Three red reflective triangles.
> Properly charged and rated fire extinguisher.
Check for optional items such as:
> Chains (where winter conditions require).
» Tire changing equipment.
List of emergency phone numbers.
Accident reporting kit (packet).
Step 4: Turn Off Engine and Check Lights
Make sure the parking brake is set, turn off the
engine, and take the key with you. Turn on
headlights (low beams) and four-way emergency
flashers, and get out of the vehicle.
Step 5: Do Walkaround Inspection
Section 2 - Driving Safely
Go to front of vehicle and check that low beams
are on and both of the four-way flashers are
Push dimmer switch and check that high beams
Turn off headlights and four-way emergency
Tum on parking, clearance, side-marker, and
identification lights.
Turn on right turn signal, and start walk-around
Walkaround and inspect.
Clean all iights, reflectors, and glass as you go
Left Front Side
Driver's door glass should be clean.
Door latches or locks should work properly.
Left front wheel.
» Condition of wheel and rim—missing, bent,
broken studs, clamps, lugs, or any signs of
» Condition of tires—properly inflated, valve
stem and cap OK, no serious cuts, bulges, or
tread wear.
» Use wrench to test rust-streaked lug nuts,
indicating looseness.
> Hub oil level OK, no leaks.
Left front suspension.
» Condition of spring, spring hangers, shackles,
» Shock absorber condition.
Left front brake.
» Condition of brake drum or disc.
> Condition of hoses.
Condition of front axle.
Condition of steering system.
> No loose, worn, bent, damaged or missing
” Must grab steering mechanism to test for
Condition of windshield.
Page 2-5
Cormercial O:ivers License Manual
7 Check for damage ard clean if dirty.
7 Check windshield wiper arms for эгорег
spring tension,
~ Check wiper blades for demage, "stiff" rubber,
and securement.
Lights and reflectors.
~ Parking, clearance, and Identification lights
ciean, operating, aid proper color (amber at
r Reflectors ciean and proper color (amber at
» Right front urn signal light clean, operating,
and prope; color (ember or white on signals
facing forward),
Right Side
Right front: cneck all items as done on left front.
Primary ana secondary safety cab locks engaged
(if cab-over-engine design).
Right fuel tankís).
Securely mounted, not damaged, or leaking.
Fuel crossover line secure,
Tank(s) contain enough fuel.
Cap(s) on and secure,
Condition of visible parts.
r Rear of engine-not leaking.
x Transmission-not lsaxing.
# Exhaust system-secure, not leakirg, not
iduching wires, fuei, or air lines.
» Frame and cross mernbers—no bends or
» Air lines and electrical wiring-secured against
shagging, rubbing, wearing.
~ Spare tire carrier or rack not damaged (if so
~ “Spare tire and/or wheel securely mounted in
= Spare lire and wheel adequate (proper size,
propeny inflated).
Cargo securement (trucks).
~ Cargo properly blockeu, braced, ied,
chained, etc.
>» Header board adequate, secure (if required).
» Side boards, stakes strong enough, free of
damage, properly sei in place (if so
» Canvas or tarp (if required) properly вестей
‘0 prevent tearing, billowing, or blocking of
» iIfoversize, all recitred signs (flags, lamps,
and ref.ectors) safely and properly mounted
and all required permits in drive's
r Curbside cargo compartment doors in cood
condition, securely closed, latched’ ocked and
required security seals in place.
Right Rear
Condition of wheels and rims-no missing, bent, or
broken spacers, studs, clamps, or lugs.
Condition of tires—properly infleted, valve stems
and caps OK, no serious cuis, bulges, read wear,
tres not rubbing each other, and nothing stuck
beiween them.
Tires same type, e.0., not mixed radiai and bias
Tires evenly matched (same sizes).
Wheel bearing/seais not leaking.
» Condition of spring(s), spring hangers,
shackles, anc u-bolts.
> Axle secure.
~ Povered axle(s) not leaking lube (gear oft).
~ Condition of torque rod arms, bushings.
5 Condition of shock absorber(s).
= fretractable axle equipped, check condition
of lit mechanism. If air powered, check for
~ Condition of air ride components.
> Brake adjustment.
# Concition of brake drum(s) or discs.
» Concition of hoses—ook for any wear due to
Lichts and reflectors.
» Side-marker lights clean, operating, and
proper ¢o'or (red at rear, others amber).
+» Side-marker reflectors clean and proper colc”
(red at rear, others amber).
Section 2 — Driving Saray
Page 2-3
Convercial drivers license Men:zai
Lights anda reflectors.
r Rear clearance and identificatior lights clean,
operating, and proper color (red at rear).
» Reilectors clean and proper color (red at
7 Tailights clean, operating, and proper color
(rec at rear).
» Right rear turn signai opsrating, and proper
color (red, yellows, or amber at rear).
license plaie(s) presert, clean. and secured.
Splash guards present, not damaged, properly
fastened, not dragging on ground, or rubbing tires.
Cargo secure (trucks).
Cargo properly blocked, braced, tied, chained, etc.
1 aliboards up anú properly secured.
End gates free of damage, pronerly secured in
stake sockets.
Canvas or tarp (if recuired) properly secured to
prevent tearing, billowing, or blocking of either the
rearview mirrors or rear lights.
H over-langth, or over-width, make sure all signs
anc/or additional lights/flags are safely and
properiy mounted and ail required permits are in
driver's possession.
Rear docrs securely closed, latched/locked.
Leit Side
Check all ‘tems as done on right side, plus:
« Bateryfies) (ii not mounted in engine
Battery box{es) securely mounted to vehicle.
Box has secure cover.
Battery(ies) secured against movement.
Battery(ies) not broken or leaking.
Fluid in battery(ies) at proper level (except
maintenance-free type).
Ceil caps present and securely tightened
{except maintenance-free type).
» Vents in cell caps free of foreign material
(except maintenance-free type).
VU YY yx
Step 6: Check Signal Lights
Get In and Turn, Of” Lights
Turn off ali lights.
Turn on stop fights (apniy trailer hand brake or
have a helper put on the brake peda).
Turn on deft turn signal lights.
Get Gtt and Check Lights
refi front turn signal light clean, operating and
proper color (amver or white on signals facing the
Lefl rear turn signal light and boty stop lights clean,
operating, and proper coior (ved, yellow, or amber).
Get In Vehicle
“urn off lights not neeced for driving.
Check for ali required papers, trip manifests,
permits, etc.
Secure all loose articles in cab (they might interfere
wi operation of the controls or hit you in a crash).
Start the engine.
Step 7: Start tre Engine and Chack
Test for Hydraulic lezks. If the vehicle has
hydraulic orakes. pump the brake pedal thee
times. Then apply firm pressure to the pedai and
hoid for five seconds. The pedal should not move.
If it does, there may be a leak or othe; problem.
Get it fixed before driving. If the vehicle has air
brakes, do the checks described in Sections 5 arc
6 of this manual.
Drake System
Test Parking ©rake(s)
Set parking brake (power unit only).
Release trailer parking brake {if applicable).
Place vehicle into a low gear.
Gently pull forward against parking brake to make
sure the parking brake holds.
Repeal the same steps for the trailer with Кейег
parking brake set and power unit parking brakes
released (if apnlicabie).
If it doesn’t hold vehicle, it is faulty; get it fixed.
Section 2 ~ Diving Safely
Page 2-7
Comercial Driver's License Manual
Test Eervice Brake Stopping Action
Go about five miles per hour.
Push brake pedal! firmiy
“Pulling” to one side or the other cen mean brake
Any unusual brake pedal "feel or delayed stopping
acron can mear trouble.
f you find anything unsafe during the pre-trip
inspecuon, get it fixed. Federal and slate laws
forbiu cperating ar unsafe vehicle.
2.1.6 ~ Insuzction During & Trp
Check Vehicie Uperation Regularly
You should check:
Air pressure gauge (if you have air brakes).
Temperature gauges.
Pressure gauges.
Cargo, cargo covers.
if you see, hear, smell, or feel anything that might
mean trouble, check it out.
Safety Inspection. Drivers of trucks and truck
tractors when transporting cargo must inspect the
securement of the cargo within the first 50 mies of
a trip and every 150 miles or every three hours
(whichever comes first) after.
2.1.7 — Alter-trip Inspection and Report
You may have lo make a written report each day
on the condition of the vehicie(s) you drove. Report
anything affecting safety or possibly leading to
mechaaical breakdown.
Subsection 2.1
fest Your Krowiledge
The vehicle inspection report tells the motor carrier
about problems tnat may need fixing. Keep a copy
of your report in ihe vehicle for one cay. Tha: vay,
the next driver can learn about any problems you
have found,
1. What is the most importan reason for
doing a vehicie inspection?
What things should you check during a
Name some key steering sysiern parts.
Name some suspension system defects.
What three kinds of emergency equipment
must you have?
What is the minimum tread depth for front
tires? For other tires?
7. Name some things you should check on
tre front of your vehicle during the
walkaround inspection.
9 sso
8. What should wheel bearing seals be
checked for?
9, How many red refieciive triangies should
you carry?
10. How do you test hydraulic brakes for
11. Why put the starter switch key it your
pocket during the pie-trip inspection?
These questions may be on your test. If you cart
answer them all, re-read subsection 2.1.
2.2 = Sasic Control of Your Vahícle:
To drive a vehicle safely, you must be able to
control its spaed and direction. Safe oneration 0” a
commercial vehicle requires ski" in:
Backing safely.
l-asten your seatbelt when on the road. Apply the
parking brake when yo: leave your vehicle.
2.2.7 ~ Accalerating
Don't roll back wien you start. You may hit
someone behind you. if you have a manual
transmission vehicle, party engage the clutch
before you take your sight foot off the brake. Put on
the parking brake whenever necessary to keep
from rolling beck. Release the parking braco only
when you have applied enough engine power to
keep from roling back. On a ‘rector-irailer
ecuipned vith a trader brake hang valve, the hand
valve can be applied to keop from ro”ing back.
Speed up smoothly ana gracually so the vehicle
does not jerx. Rough ecceleration can caus::
Scction 2 — Driving Dareiy
Page 2-6
Cormeicial Drive"s License Marvua?
mechanical damage. When pulling a trailer, rough
acceleration can damage the coupling.
Sneed up very giadua.y when fraction is poor, as
in rain or snow. If you use too much power, the
drive wheels may spin. You could lose contro). №
the drive vheels begin to spin, {ake your foot off
the accelerator.
2.2.2 — Bleering
Hold the s'eerirg whee: firmly with both hands.
Your hands should be on opposite sides of the
wheel. If vou hit a curb or a pothole (chuckiole),
the wheel could pull awey from your hands unless
you have a firm hold.
2.2.3 - Stopping
Push the brake pedal down gradually. The amount
of brake pressure you need to stop the vehicle wil;
depend on the speed of the vehicle and how
quickly you need to stop. Control the pressure so
the vehicle comes to a smooth, safe stop. If you
nave a manual transmission, push the clutch in
when lhe engine is close to idie.
2.2.4 — Backing Safely
Because you cannot see everything behind your
vehicle, backing is always dangerous. Avoid
backing whenever you car. When you park, try to
park so you will oe abe to pull forward when you
leave. When you have to back, here are a few
simple safety rules:
Siart in the proper position.
Look at your path.
Use mirrors on both siues.
Back slowly,
Back and turn toward the driver's side whenever
Use z helper whenever possible.
These rules are discussed in turn below.
Start in the Proper Position. Put the vehicle in
the best position to allow you to back safely. This
position wil: depend on the type of backing to be
LOOK ac Your Path, Look at your line of travel
before you begin. Get out and walk around ihe
vehicle. Check your ciearance to the sides and
overhead, In and near the path your vehicle wil;
Use Mirrors or Both Sides. Check the outsice
mirrors on both sides frequently. Get out of the
vehicle and check your path if you are unsure.
Zack Slew!y. Always back as slowly as possiole.
Use the lowest reverse gear. That way you can
more easily correct any steering errors. You also
can stop quickly if necessary.
Back ard ¿urn Toward ihe Drivers Side. Back
to the driver's side so you can see better. Backing
toward the right side is very dangerous because
you can't see as well. if you back and turr toward
the driver's side, you can watch the rear of your
vehicie by looking out the side window. Use driver-
side bacring-even if it means goirg around the
block io put your vehicle in this position. The
adued safety is worth it.
Use a Helper, Use a helper whan you can. Thea
are blind spots you can't see. That's why a helper
is important. The helper should stand near the
back of your vehicle where you can see the helper.
Before you begin backing, work out a set of hand
signals that you both understand. Agree on г
signal for “stop.”
2.2 — Shifting Gears
Correct shifting of gears is important. if you can't
get your vehicle ‘nto the right gear while driving,
you will have less control.
2.3.1 — flanual Transmissions
Ваз Method fur Shifting Up. Most heavy
vehicles with manual transmissions require double
clufching to change gears. This ‘$ the basic
Release accelerator, push in cluich and shift to
neutral at the same time.
Release clutch.
Let engine and gears siow down to the rpm
required for the next gear (this takes practice).
Push in dutca and shift to the higher gear at the
same time.
Revase clutch and press accelerator at the same
Shilling gears using double clutching -eouires
practice. if you remain too long in neutra", you may
have cifficuity putting the vehicle into the next
gear. If so, don't try to force it. Return io neutral,
release cluich, increase engine speed to malch
road speed, ard try again,
Section 2 — Driving Safely
Page 2-9
Commercial Driver's License Manual
Knowing Wien to Shifi Up. There are two ways
of knowing whan to shift;
Use Engine Speed (rpm). Study the driver's
manual for your venicle and learn the operating
rpm range. Watch your tachometer, and shift up
when your engine reaches the top of the range.
(Some newer vehicles use “progressive” shifting:
the rpm at which you shift becomes higher as you
move up in the gears. Find out what's right for the
vehicle you wil! operate.)
Jse Road Speed {mph). Learn what speeds each
gear is good for. Then, by using the speedomeier,
you'll know wien to shift up,
With either method, you may learn to use engine
sounds to know when to shift.
3asic Procedures for Shifting Down
Release accelerator, push in clutch, and shift to
neutral at the same time.
Release clutch,
Press acceierator, increase engine and gear speed
to the rpm required in the 'ower gear.
Push in clutch and shift to lower gear at the same
Release clutch and press accelerator at the same
Downshifting, like upshifting, requires knowing
when to shift. Use either the tachometer or the
speedometer and downshift at the right rpm or
road speed.
Specia: conditions where you shoud downshift
Before Starting Down a Hi. Slow down and shift
down lo a speed trat you can control without using
the orakes hard. Otherwise the brakes can
overheat and lose their braking power.
Downshift before starting cown the hill. Make sure
you are n a low encugh gear, usually lower thar
the gear required to climb the same il.
Before Entering a Curve. Slow down to a safe
speed, anc downshift to the right gear before
entering the curve. This lets you use some power
through the curve to help the vehicle be more
stabie while turning. It aso allows you to speed up
as soon as you are out of the curve.
ê 22 — iidti-s peed Rear Axles aiid
Auxiliary Transmissions
Muit-speed rear axles and auxiliary transmissions
are used on .neny vehicles to provide extra gears.
You usually control them by a selector knob or
switch on the gearshift lever of the main
transmission. There are many different shift
patterns. Learn the right way to shift gears in the
vehicle you will drive.
2.3.3 — Automatic Transmissions
Some venicles have automatic transmissions. You
can seeci alow range to get greater engine
braking wnen going down grades. The lower
ranges prevent the transmission from shifing up
beyond the selected gear (unless tha governor rpm
is exceeded). it is very important to use this
braking effect when going down grades,
2.3.3 — Retarders
Some vehicles have Tetarde:s." Retarcers help
slow a vehicle, reducing the need fo: using your
brakes. “hey reduce brake wear and give you
another wey to slow down, There are four basic
types of retarders {exhaust, engine, hydraulic, and
electric). Ail retarders can be turned on or off by
the driver. On some vehicies the retarding power
can be adjusted. When turned “on,” retarders apply
ther braking power (to the drive wheels only)
whenever you let up on the accelerator pada’ a)
the way.
Because these devices can be noisy, be sure you
know where their use is permitted.
Caution. When your drive wheels have poor
traction, the retarder may cause them to skid.
Therefore, you shou's turn the retarder off
whenever the road is wet, icy, or snow covered.
Sa o Ee EE
Subsectione 2.2 and 2.3
vest Your Knowledge
1. Why should you back toward the driver's
2. If stopped on a hil, "ow can you start
moving without rolling back?
3. When backing, why is it important to use a
hei per?
4. What's the most ‘mportant hand signal that
you ano the ne'per should agree on?
5. What are the to special conditions where
vou shou:G downenit?
Section 2 — Driving Ssfeiy
Pag: 2-*0
Commercial Driver's License Manual
B. When should you downshift automatic
7. Retarders keep you from skidding when
the road is slippery. True or False?
8, What are the two ways to know when to
These questions may be on the test. If you can't
answer them all, re-read subsections 2.2 and 2.3.
e os os A ESS аннЫ
2.4 ~ Seeing
To be a safe driver you need to know what's going
on all around your vehicle. Not looking properly is a
major cause of accidents.
2.4.1 - Secing Ahead
All drivers look ahead; but many don't look far
enough ahead.
importance of Looking Far Enough Ahead.
Because stopping or changing lanes can take a fot
of distance, knowing what the traffic is doing on all
sides of you is very important. You need to look
well ahead to make sure you have room to make
these moves safely.
How Far Ahead to Look. Mast good drivers look
at least 12 to 15 seconds ahead. That means
looking ahead the distance you will travel in 12 to
16 seconds. At lower speeds, that's about one
block. At highway speeds it's about a quarter of a
mile, If you're not looking that far ahead, you may
have lo stop too quickly or make quick lane
changes. Looking 12 to 15 seconds ahead doesn't
mean not paying attention to things that are closer.
Good drivers shift their attention back and forth,
near and far. Figure 2.6 illustrates how far to look
12-15 Seconds is About One Block 12-15 Seconds is About À uartor- Mila
Figure 2.6
Look for Traffic. Look for vehicles coming onto
the highway, into your lane, or turning. Watch for
brake lights from slowing vehicles. By seeing these
things far enough ahead, you can change your
speed, or change lanes if necessary to avoid a
problem, If à traffic light has been green for a long
time it will probably change before you get there.
Start slowing down and be ready to stop.
2.4.2 — Seeing to the Sides and Rear
№5 important to know what's going on behind and
to the sides. Check your mirrors regularly. Check
more often in special situations.
Mirror Adjustment. Mirror adjustment should be
checked prior to the start of any trip and can only
be checked accurately when the trailer(s) are
straight. You should check and adjust each mirror
to show some part of the vehicle. This will give you
a reference point for judging the position of the
other images.
Regular Checks. You need to make regular
checks of your mirrors to be aware of traffic and to
check your vehicle.
Traffic. Check your mirrors for vehicles on either
side and in back of you. In an emergency, you may
need ta know whether you can make a quick lane
change. Use your mirrors to spot overtaking
vehicies. There are “blind spots” that your mirrors
cannot show you. Check your mirrors regularly to
know where other vehicles are around you, and to
see if they move into your blind spots.
Check Your Vehicle. Use the mirrors to keep an
eye on your tires, It's one way to spot a tire fire. If
you're carrying open cargo, you car use the
mirrors to check it. Look for loose straps, ropes, or
chains. Watch for a flapping or ballooning tarp.
Special Situations. Special situations require
more than regular mirror checks. These are lane
changes, turns, merges, and tight maneuvers.
Lane Changes. You need to check your mirrors to
make sure no one is alongside you or about to
pass you. Check your mirrors:
Before you change lanes to make sure there is
enough room.
After you have signaled, to check that no one has
moved into your blind spot.
Right after you start the lane change, to double-
check that your path is clear.
After you complete the lane change.
Section 2 — Driving Safely
Page 2-11
Commercial Driver's License Manual
Turns. In turns, check your mirrors to make sure
the rear of your vehicle will not hit anything.
Merges. When merging, use your mirrors to make
sure the gap in traffic is large enough for you to
enter safely.
Tight Maneuvers. Any time you are driving in
close quarters, check your mirrors often. Make
sure you have enough clearance.
How to Use Mirrors. Use mirrors correctly by
checking them quickly and understanding what you
When you use your mirrors while driving on the
road, check quickly. Look back and forth between
the mirrors and the road ahead. Don't focus on the
mirrors for too long. Otherwise, you will travel quite
a distance without knowing what's happening
Many large vehicles have curved (convex,
“fisheye,” “spol,” "bugeye”) mirrors that show a
wider area than flat mirrors. This is often helpful.
But averything appears smaller in a convex mirror
than it would if you were looking at it directly.
Things also seem farther away than they really are.
it's important to realize this and to allow for it.
Figure 2.7 shows the field of vision using a convex
a TA Mirror Spot [ Mirror “Mirror
EUA View) Area, View PUTA
Figure 2.7
2.5 - Communicating
2.5.1 — Signal Your intentions
Other drivers can't know what you are going to do
until you tell them.
Signaling what you intend to do is important for
safely. Here are some general rules for signaling.
Turns. There are three good rules for using turn
Signal early. Signal well before you turn. it is the
best way to keep others from trying to pass you.
Signal continuously. You need both hands on the
wheel to turn safely. Don’t cancel the signal until
you have completed the turn.
Cancel your signal. Don't forget to turn off your turn
signal after you've turned (if you don't have self-
canceling signals).
Lane Changes. Put your turn signal on before
changing lanes. Change lanes slowly and
smoothly. That way a driver you didn't see may
have a chance to honk his/her horn, or avoid your
Slowing Down. Warn drivers behind you when
you see you'll need to slow down. A few light taps
on the brake pedal — enough to flash the brake
lights — should warn following drivers. Use the four-
way emergency flashers for times when you are
driving very slowly or are stopped. Warn other
drivers in any of the following situations:
Trouble Ahead. The size of your vehicle may make
it hard for drivers behind you to see hazards
ahead. If you see a hazard that will require slowing
down, warn the drivers behind by flashing your
brake lights.
Tight Turns. Most car drivers don't know how
slowly you have to go to make a tight turn in a
large vehicle. Give drivers behind you warning by
braking early and slowing gradually.
Stopping on the Road. Truck and bus drivers
sometimes stop in the roadway to unload cargo or
passengers, or to siop at a railroad crossing. Warn
following drivers by flashing your brake lights.
Don’t stop suddenly.
Driving Slowly. Drivers often do not realize how
fast they are catching up to a slow vehicle until
they are very close, If you must drive siowly, alert
following drivers by turning on your emergency
flashers if it is legal. (Laws regarding the use of
flashers differ from one state to another. Check the
laws of the states where you will drive.)
Section 2 - Driving Safely
Page 2-12
Commercial Driver's License Manual
Don’t Direct Traffic. Some drivers try to help out
others by signaling when it is safe to pass. You
should not do this. You could cause an accident.
You could be blamed and it could cost you many
thousands of dollars.
2.5.2 - Communicating Your Presence
Other drivers may not notice your vehicle even
when it's in plain sight. To help prevent accidents,
let them know you're there.
When Passing. Whenever you are about to pass
a vehicle, pedestrian, or bicyclist, assume they
don’t see you. They could suddenly move in front
of you. When it is legal, tap the horn lightly or, at
night, flash your lights from low to high beam and
back. And, drive carefully enough to avoid a crash
even if they don’t see or hear you.
When It's Hard to See. At dawn, dusk, in rain, or
snow, you need to make yourself easier to see. If
you are having trouble seeing other vehicles, other
drivers will have trouble seeing you. Turn an your
lights. Use the headlights, not just the identification
or clearance lights. Use the low beams, high
beams can bother people in the daytime as well as
at night.
When Parked at the Side of the Road. When you
puli off the road and stop, be sure to turn on the
four-way emergency flashers. This is important at
night. Don't trust the taillighls to give warning.
Drivers have crasned inio ihe rear of a parked
vehicle because they thought it was moving
if you must stop on a road or the shoulder of any
road, you must put out your emergency warning
devices within ten minutes. Place your warning
devices at the following iocations:
If you must stop on or by a one-way or divided
highway, place warning devices 10 feet, 100 feet,
and 200 feet toward the approaching traffic. See
Figure 2.8.
If you stop on a two-lane road carrying traffic in
both directions or on an undivided highway, place
warning devices within 10 feet of the front or rear
corners to mark the location of the vehicle and 100
feet behind and ahead of the vehicle, on the
shoulder or in the lane you stopped in. See Figure
One-Way or Divided Highway
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Figure 2.8
Two-Way or Undivided Highway
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Figure 2.9
Back beyond any hill, curve, or other obstruction
that prevents other drivers from seeing the vehicle
within 500 feet. If line of sight view iz obstructed
due to hill or curve, move the rear-most triangle to
a point back down the road so warning is provided.
See Figure 2.10.
Section 2 — Driving Safely
Page 2-13
Commercial Driver's License Manual
|e 100-500 ——
100`- 500°
pci 2 En
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Figure 2.10
When putting out the triangles, hold them between
yourself and the oncoming traffic for your own
safety. (So other drivers can see you.)
Use Your Horn When Needed. Your horn can let
others know you're there. It can help to avoid a
crash. Use your horn when needed. However, it
can startle others and could be dangerous when
used unnecessarily.
2.6 — Controlling Speed
Driving too fast is a major cause of fatal crashes.
You must adjust your speed depending on driving
conditions. These include traction, curves, visibility,
traffic and hills.
2.6.1 — Stopping Distance
Perception Distance + Reaction Distance +
Braking Distance =Total Stopping Distance
Perception Distance. This is the distance your
vehicle travels from the time your eyes see a
hazard until your brain recognizes it. The
perception time for an alert driver is about 3/4
second. At 55 mph, you travel 60 feet in 3/4
second or about 81 feet per second.
Reaction Distance. The distance traveled from
the time your brain tells your foot to move from the
accelerator uniil your foot is actuaily pushing the
brake pedal. The average driver has a reaction
time of 3/4 second. This accounts for an additional
60 feet traveled at 55 mph.
Braking Distance. The distance it takes fo stop
once the brakes are put on. At 55 mph on dry
pavement with good brakes, it can take a heavy
vehicle about 390 feet to stop. It takes about 4 1/2
Total Stopping Distance. At 55 mph, it will take
about six seconds to stop and your vehicle will
travel about 450 feet.
The Effect of Speed on Stopping Distance.
Whenever you double your speed, it takes about
four times as much distance to stop and your
vehicle will have four times the destructive power if
it crashes. High speeds increase stopping
distances greatly. By slowing down a little, you can
gain a lot in reduced braking distance. See Figure
Stopping Distance Chart
Miles | How Far | Driver Vehicle | Total
Per | The Rig | Reaction | Braking | Stopping
Hour Will Distance | Distance | Distance
Travel in |
Second |
15mph | 228. 171 29 ft 46 ft.
30 mph | 44 33 ft 115 ft. 148
45 mph | 68%. 50 ft. 260 ft. 310 fi.
50mph | 73% 55 ft. 320 ft. 37/51
56mph | 81f 61 ft so. | 4511
Figure 2.11
The Effect of Vehicle Weight on Stopping
Distance. The heavier the vehicle, the more work
the brakes must do to stop it, and the more heat
they absorb. But the brakes, tires, springs, and
shock absorbers on heavy vehicles are designed
to work best when the vehicle is fully loaded.
Empty trucks require greater stopping distances
because an empty vehicle has less traction.
Section 2 ~ Driving Safely
Page 2-14
Commercial Driver's License Manual
2.6.2 patching Speed io the Road
You can't steer or brake a vehicle unless you have
traction. Traction is friction between the tires and
the road. There are some road conditions that
recuce traction and call for lov. er speeds.
Slippery Surfaces. it will take longer to stop, and
it wil be narder to turn without skidding, when the
road is slippery. Wet roads can double stopping
distance, You must drive slower to be able to stop
‘п the same distance as on a dry road. Reduce
speed by about one-third (e.g., slow from 55 to
about 35 mph) on a wet road. On packed snow,
reduce speed by a hall, oi more. If the surface is
icy, reduce speed ta a crawl and stop driving as
soon as you can safely ao so.
Identifying Slippery Surfaces. Sometimes it's
hard to know if the road is sIppe-y. Here ar2 some
signs of slippary roads:
Shaded Areas. Shady parts of the road will remain
icy and slinpery long after open areas have melted.
Bridges. When the temperature drops, bridges will
freeze before the road will. Be especially careful
when the temperature is close to 32 degrees
meltina ice. Slignt melting will make ice wet. Wet
ice is muci? more slippery than ice that is not wet.
Elacx ice. Black ice is 2 thin layer that is clea
enough that you can see the road underneath it. it
makes the road look wet. Any time the temperature
is belov: freezing and the road looks wet, watch out
for black ice.
Vehicle Icing. An easy way to check for ice is to
open the window and feel tre front of the mirror,
rairror support, or antenna. if there's ice on these,
the road suriace is probably starting to ice up.
Just After Rain Begins. Right after it starts fo
rain, the water mixes vth o left on the road oy
vehicies. This makes ihe road very slippery. If tha
rain continues, it will wash the oil away.
Hydroplaning. In some weather, waler or slush
collects on the road. When this happens, your
vehicle can hydroplane. It's Ixe water s«ing-the
tires lose their contact with the road and nave little
or no traction. You may not be able to steer or
brake. You can regain contrul by releasing the
accelerator and pushing in the clutch. This will slow
your venicle and let the wheels tura freely. If tie
vehicle is hydroplaning, do no! use the brakes to
s:ow down. if the drive wheels start to skid, pusn in
the cluich ‘o let them turn freely.
Section 2 - Divina Safely
it does not take a lot of waie- to cause
hydrop:aving. Hydroplaning can occur al speeds
as iow as 30 mph if there is a lot of water.
Hydropianing is more likely if tire pressure is ‘ow,
or the tread is worn. (The grooves in a tire carry
away the water; if they aren't deep, thoy don't work
Road surfaces where water can collect can create
conditions thet cause a vehicle to hydroplane.
Watch for cear reflections, tire splashes, and
raindrops on the road. These are indications of
standing water.
<. 6.2 ~ Speed and Curves
Drivers must adjust their speed for curves in the
road. If you take a curve too fasi, two things car
happer. Tne tires can iose their traction and
contnue straight ahead, so you skid off the road.
Or, the tires may keep their traction and tne vehicle
roËs over. Tests have shown that trucks with a high
center of gravity can roll over at the posted speed
limit for a curve.
Slow to a safe speed before you enter a curve.
Braking in a curve is dengerous because it is
easier to lock the wheels and cause a skid. Stow
down as needed. Don't ever exceed {hs posted
speed limit for the curve. Be in a gear that wil let
you accelerate s.ightly in the curve. This will helo
you keep control.
£.6.4 — Speed and Distance Alcad
You should always be able to stop within the
distance you can see ahead. Fog, rair, or other
conditions may require that you s:ow down to be
able to stop in the distance you can see. Al night,
you cant see as “ar with low beams as you car
with high beams. When you must use iow beams,
sion dom.
4.6.5 —- Sveed and Traffic Fiow:
When you're driving in heavy traffic, the safest
speed is tha speed of other vehicles. Vehicles
going the seme direciion at the same speed are
not likely to run into one another. ir many states,
speed limits are lower for trucks and buses than for
cars. it can vary as much as 15 mph. Use extra
caution when you change lanes or pass on thase
roadways. Drive at the speed of the trafic, i vou
can without going at an llega. or unsafe speed.
Keep a sale following distance.
Pags 2-15
0irercial Dreiver's License Manual
The mair reason drivers exceed speed limits :s to
save time. But, anyone trying to drive faster than
the speed of traffic will not be able to save much
time. The risks involved are not worth it. if you go
faster then the speed of other traffic, you'll have io
keep passing other vehicles. This increases the
chance of a crash, and it is more tring. Fatigue
increases the chance of a crash. Going with the
flow of traffic is safer and easier.
2.6.6 ~ Speed on Downgrades
Your vehicle's speed will increase on downgrades
because of gravity. Your most important objective
is to select and maintain a speed that is no: too
fast for the:
Total weight of the vehicle anc cargo.
Length of the grade.
Steepress of the grade.
Road conditions.
M a speed limit is posted, or there is a sign
indicating “Maximum Safe Sneed,” never exceed
the speed show. Also, look for and heed warming
signs indicating the length and steepness of the
grade. You must use tre braking effect of the
engine as {пе principal way of controling your
speed on downgrades. The braking effect of the
engine is greatest when it is near the governed
roms and the transmission is in the lower gears.
Save your brakes so you will be able to slow or
stop as requiret by road and traffic conditions.
Shift your transmission to a low gear before
starting down the grade and use the proper
braking techniques. Please read carefully the
section on going down long,. steep downgrades
safely in “Mountain Driving.
2.6.7 — Roadway Work Zones
Speeding frafiic is the number one cause of injury
and death in roadway work zones. Observe the
posted speed ¡imits at all times when approaching
and driving through a work zone. Watch your
spsecometer, and don't allow your speed to creep
up as you drive through wong sections of road
construction. Decrease your speed for adverse
weather or road conditions. Decrease your speed
ever furiher when a worker is close to the
Subsections 2.4, 2.5, and 2.6
Test Y cur Encwledge
1. Hows far ahead does the manual say you
should look?
2. What cre two main things to look for
3. What's your most important way to see the
sides and rear of your vehicle?
4. What does “communicating” mean in sale
5. Where should your reflectors be placed
when stopped on a divided highway?
5, What three things add up to total stopping
7. If you go twice as fast, will your stonping
distanca increase by two or four mes?
8. Empty trucks have the best braking. True
or False?
9. What is hydrozlaning?
10. What is “black ice”?
These questions may be on the tesi. If you can't
answer them 21, re-read subsections 2.4, 2.5, and
2.7 -- Managing Space
зо be a safe driver, you need space all around
your vehicle. When tnings go wrong, space gives
you time to think and to take action.
To have space availabe when something goes
wrong, you neet to manage space. While this is
true for al! drivers, it is very important for large
vehicles. They take up more space and they
require more space for stopping and turning.
2.7.1. Space Ahead
Of al: the space around vour vehicle, it is the area
ahead of the vehicle-the space you're criving inte
—ihat is most important.
The Need for Space Ahcad. You need space
ahead in case you must suddenly stop. According
i0 accident reports, the vehicle thal trucks anú
buses most often run into is the one in front of
them. The most frecuent cause is following too
c:osely. Remeraber, if the vehicle ahead of you is
smaier tran yours, k can probably stop faster than
you can. You may crash if you arc followirge 100
Section 2 — Jriving Safely
Page 2-16
Commercial Driver's License Manual
How Much Space? How much space should you
keep in front of you? One good rule says you need
at least one second for each 10 feet of vehicle
length at speeds below 40 mph. At greater speeds,
you must add 1 second for safety. For example, if
you are driving a 40-foot vehicle, you should leave
4 seconds between you and the vehicle ahead. In
a 60-foot rig, you'll need 6 seconds. Over 40 mph,
you'd need 5 seconds for a 40-foot vehicle and 7
seconds for a 60-foot vehicle. See Figure 2.12.
To know how much space you have, wait until the
vehicle ahead passes a shadow on the road, a
pavement marking, or some other clear landmark.
Then count off the seconds like this: “one
thousand- and-one, one thousand-and-two” and so
on, until you reach the same spot. Compare your
count with the rule of one second for every ten feet
of length.
For timed interval following distance
* | second required for each 10 feet of
vehicle length at speeds under 40 MPH
* Above 40 MPH use same formula, then
add 1 second for the additional speed
60 foot truck (under 40 MPH) = 6 seconds
Figure 2.12
If you are driving a 40-foot truck and only counted
up to 2 seconds, you're too close. Drop back a little
and count again until you have 4 seconds of
following distance (or 5 seconds, if you're going
over 40 mph). After a little practice, you will know
how far back you should be. Remember to add 1
second for speeds above 40 mph. Also remember
that when the road is slippery, you need much
more space to stop.
2.7.2 — Space Behind
You cant stop others from following you too
closely. But there are things you can do to make it
Stay to the Right. Heavy vehicles are often
tailgated when they can’t keep up with the speed
of traffic. This often happens when you're going
uphill. If a heavy load is slowing you down, stay in
the right lane if you can. Going uphill, you should
not pass another slow vehicle unless you can get
around quickly and safely.
Dealing with Tailgaters Safely. in a large vehicle,
it's often hard to see whether a vehicle is close
behind you. You may be tailgated:
When you are traveling slowly. Drivers trapped
behind siow vehicles often follow closely.
in bad weather. Many car drivers follow large
vehicles ciosely during bad weather, especially
when it is hard to see the road ahead.
if you find yourself being tailgated, here are some
things you can do to reduce the chances of a
Avoid quick changes. If you have to slow down or
turn, signal early, and reduce speed very gradually.
Increase your following distance. Opening up room
In front of you will help you to avoid having to make
sudden speed or direction changes. It also makes
it easier for the tailgater to get around you.
Dont speed up. It's safer to be tailgated at a low
speed than a high speed.
Avoid tricks. Don't turn on your taillights or flash
your brake lights. Follow the suggestions above.
2.7.3 ~ Space to the Sides
Commercial vehicles are often wide and take up
most of a lane. Safe drivers will manage what little
space they have. You can do this by keeping your
vehicle centered in your lane, and avoid driving
alongside others.
Staying Centered in a Lane. You need to keep
your vehicle centered in the lane to keep safe
clearance on either side. If your vehicle is wide,
you have little room to spare.
Section 2 — Driving Safely
Page 2-17
Commercial Driver's License Manual
Traveling Next to Others. There are two dangers
in traveling alongside other vehicles:
Another driver may change lanes suddenly and
turn into you.
You may be trapped when you need to change
Find an open spot where you aren't near other
traffic. When traffic is heavy, it may be hard to find
an open spot. If you must travel near other
vehicies, try to keep as much space as possible
between you and them. Also, drop back or pull
forward so that you are sure the other driver can
see you.
Strong Winds. Strong winds make it difficult to
stay in your lane. The problem Is usually worse for
lighter vehicles. This problem can be especially
bad coming out of funnels. Don't drive alongside
others if you can avoid it.
2.7.4 — Space Overhead
Hitting overhead objects is a danger. Make sure
you always have overhead clearance.
Don't assume that the heights posted at bridges
and overpasses are correct. Re-paving or packed
snow may have reduced the clearances since the
heights were posted.
The weight of a cargo van changes its height. An
empty van is higher than a loaded one. That you
got under a bridge when you were loaded does not
mean that you can do it when you are empty.
If you doubt you have safe space to pass under an
object, go slowly. If you aren't sure you can make
it, take another route. Warnings are often posted
on low bridges or underpasses, but sometimes
they are not.
Some roads can cause a vehicle to tilt. There can
be a problem clearing objects along the edge of
the road, such as signs, trees, or bridge supports.
Where this is a problem, drive a litlle closer to the
center of the road.
Before you back into an area, get out and check
for overhanging objects such as trees, branches,
or electric wires. I's easy to miss seeing them
while you are backing. (Also check for other
hazards at the same time.)
2.7.5 - Space Below
Many drivers forget about the space under their
vehicles. That space can be very small when a
vehicle is heavily loaded. This is often a problem
on dirt roads and in unpaved yards. Don't take a
chance on getting hung up. Drainage channels
Section 2 — Driving Safely
across roads can cause the ends of some vehicles
to drag. Cross such depressions carefully.
Railroad tracks can also cause problems,
particularly when pulling trailers with a low
underneath clearance. Don't take a chance on
getting hung up halfway across,
2.7.6 — Space for Turns
The space around a truck or bus is important in
turns. Because of wide turning and offtracking,
large vehicles can hit other vehicles or objects
during turns.
Right Turns. Here are some rules to help prevent
right-tumm crashes:
Turn slowly to give yourself and others more time
to avoid problems.
If you are driving a truck or bus that cannot make
the right turn without swinging into another lane,
turn wide as you complete the turn. Keep the rear
of your vehicle close to the curb. This will stop
other drivers from passing you on the right.
Dort't turn wide to the left as you start the turn. À
following driver may think you are turning left and
try to pass you on the right. You may crash into the
other vehicle as you complete your tum.
If you must cross into the oncoming lane to make a
turn, watch out for vehicles coming toward you.
Give them room to go by or to stop. However, don't
back up for them, because you might hit someone
behind you. See Figure 2.13.
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Figure 2.13
Left Turns. On a left turn, make sure you have
reached the center of the intersection before you
start the left turn. If you turn too soon, the left side
Page 2-18
Commercial Driver's License Manual
of your vehicie may hit another vehicie because of
if there are two turning lanes. always take the right
turn lane. Dori start in the inside lane because
you may have to swing right to make the turn.
Drivers on your left can be more readily seen, See
Figure 2.14.
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Figu re 2. 14
2.7.7 — Space Needed to Cross or Enter
Be aware of the size and weight of your vehicle
v:hen yau cross or enter traffic. Here are some
important things to keep in mind.
Because of s ow acceleration and the space large
vehicles require, you may need a much larger gap
to enter tiaffic than you would in a car.
Acceleration varies with the load. Allow more room
if your venicle is heavily .Áaded,
Before you start across a road, make sure you can
cet all the way across before traffic reaches you.
2.8 ~ Seeing Hazards
2.8.1 - Impcriance of Seeing Feazards
Wnat ls a Hazard? A hazard is any road condition
or other road user (driver, bicyclist, pedestrian) that
is a possible danger. For example, a car in front of
you is headed toward the freeway exit, but his
brake lights come on and he begins braking hard.
This could mean that the driver is uncertain about
taking the off ramp. He might suddenly return to
the highway. This car is a hazard. If the driver of
the car cuts in front of you, it is no longer just a
haza-d; il is an emergency.
Seeing Hazards Lets You Be Prepared. You will
have more lime to act if you see hazards before
they become emergencies. In the example above,
you might make a ane change or slow down (0
prevent a crash if the car suddenly cuts in front of
you. Seeing tnis hazard gives you lime to check
your mirrors and signal a lane change. Beirg
prepared reduces the danger. A driver wno dig not
see the hazard until the slow car pulled back on
the highway in front of him would have to do
something very suddenly. Sudden braking or a
quick lane change is much more likely to lead to a
Learning to See Hazards, here are often clues
that will nelp you see hazards. The more you drive,
the better vou car learn to see hazarcs. Tnis
section will alk about hazards that you should be
aware or.
2.8.2 Hzzaroous Koads
Slow down and be very careful if you see any of
the following road hazards.
Work Zones, When neople are working on the
road, it is a hazard. There inay be narrower lanes,
sharp turas, or uneven surfaces. Other drivers are
cften distracted and orive unsafely. Workers and
construction vehicles may get in the way. Drive
slowly and carefully near work zones. Use your
four-way flashers or brake lights to warn drivers
behind you.
drop Off. Sometimes the pavement drops off
sharply near the edge of the road. Driving too near
the edge can tilt your vehicle toward the side of the
road. This can cause the top of your vehicle to hit
roadside objects (signs, tree limbs). Also, ii can be
hard to steer as vou cross the drop off, going off
the road, or coming pack on.
Foreign Jziects. Things that have fallen on the
road can be hazards. They can be a danger to
your tires and wheel rims. They can damage
electrical and brake lines. They can be czught
between dual tires and cause severe damage.
Some obstacles that appear to he harmless can be
very dangerous. For example, carcboard boxes
may be empiy, but trey may also centain some
soid or heavy material capable of causing
damage. The same is true of paper and cloth
sacks. It is important to remain alert for objects of
all sorts, so you can see them early enough to
avoid them withoul making sudden, unsafe moves.
Section 2 - Driving Safaly
Prge 72-19
Camracreial Driver's Licerse Manual
Oif Kemps/On Ramps. Freeway and turnpike
exits car be particularly dangerous for commercial
vehicles. Off ramps and or ramps often have
speed :imit signs posted. Remember, these speeds
may be safe for automobiles, but may not be safe
‘or larger vehicles or heavily loeded vehicles. Exits
hat go downhili and turn at the same time can be
especially dargerous. The downgrade makes it
difficult to reduce speed. Braking and turning at the
same time can be a dangerous practice. Nake
sure you are coing slo ly enough before you get
on the curved pert of an off ramp or on remp.
7.8.3 — Drivers Who fire Hezards
In order to protect vourse!f and others, you must
know when other drivers may do something
hazardous. Some clues to this type of hazard are
discussed below.
Hiccked Vision. People who can't see others are
a very dangerous hazard. Be alert for drivers
whose vision is biocked. Vans, ipaded station
wagons, and cars with the rear window blocked are
exampies. Rental trucks shoud be watched
carefully. “heir drivers are often not used to the
limited vision they have to tha sides and rear of the
truck. In winter, vehicles with frosied, ice-covered,
or snow-covered windows are hazards.
Vehicles may be partly híccen by blind
imersections or alleys. If yout only can see the rear
or front end of a vehicle but rot the driver, then he
or she can't see you. Be alert because he/she may
back out or enter into your lane. Always be
prepared to stop.
Delivery Trucks Can Presen a Hazard.
Packages or vehicle doors often block the driver's
vision, Drivers of slep vans, postal vehicles, and
local delivery vehicles often are in a hu:ry and may
suaderly step out of their vahicle or drive their
vehicle into the traffic lane.
Parxed Vehicies Can Be Harards, especialy
when people start io get out of them. Or, they may
sucdeniy start up and drive into your way. Watch
‘or movement inside the vehicle or movement of
the vehicle iiself that shows people are Inside.
Watch for brake lights or backup fights, exhaust,
and other clues that a driver is ebout to move.
Be care‘u of a stopped bus. Passengers may
cross in front of or behind the bus, and they ойег,
cant see you.
Pecestrians and Sicyclists Can Also Ее
razerds. Walkers, ‘oggers, and bicvciists may be
on the road with their back to the traffic, so they
cant see you. Sometimes they wear portable
stereos with headsets, so they can't hear you
either. This can be dengerous. On rainy days,
pedestrians may not see you because of hats or
umorellas. They may be hurrying to get out of the
rain and may not pay attention to the traffic.
Distractions, People who sare distracted are
hazards. Watch for +: here they are looking. If they
are ooking elsewhery, they can't see you. But be
alert even when they are looking at you. They may
believe that they have ha right of way,
Children. Children tend to act quickly without
checking traffic. Chiidren playing with one another
may not look for traffic and are a serious hazard.
Taikers. Drivers or pedestrians talking to one
another may rot be paying close attention lo the
Workers. People working on or rear the roadway
are a hazard clue. The work creates a distraction
for other drivers and the workers themselves may
not see you:
ice Cream Trucks. Someone selling ice cream is
a hazard clue. Children may be nearby and may
not see you.
Disabled Vehicles. Drivers changing a tire or
fixing an engine often do rot vay a:teniion to the
danger that roadway traffic is to them. They are
often careless. Jacked up wheels o: raised hoods
are hazard clues.
Accidents, Accidents are particularly hazardous.
People involved in the accidert may not loox for
vaffic. Passing drivers tend to look at the accident.
Peopie often run across the road without looking.
Vehicies may slow or stop suddeniy.
Shoppers. People in znd around shopping areas
are often not watching traffic because they are
looking fo- stores or looking into store windows.
Confusca Drivers, Confused drivers often change
direction suddenly or stop without warring.
Confusion is common near freeway or turnpike
intercierges and major iniersections. Tourists
uniamiliar with the area can be very hazardous.
Ciues to tourists include car-top luygage and out-
of-state license plates. Unexpected actions
(stopping in the middle of € block, changing lanes
Section 2 — Driving Safe:y
Rage 2-20
Conunercial Driver's License Manual
for no apparent reason, backup lights suddenly
going on) are clues to confusion. Hesitation is
another clue, incluging driving very slowly, using
orakes often, or stoppirg in the middle of an
intersection. You may also see drivers who are
looking at street signs, maps, and house numbers.
These drivers may not be paying attention to you.
Slow Lrivers. Motorists who fail to maintain
normal speed are hazards. Seeing slow moving
vehicles aarly can prevent a crash. Some vehicles,
by their nature, are siow and seeing them is a
hazard clue (mopeds, farm machinery,
construction machirery, tractors, etc.). Same of
these will have the "sow moving vehicie” symbos to
warn you. This is a red triangle with an orange
center. Wacch for it.
Orivers Signaling 2 Turn Way Be a Hazard.
Drivers signaling a turn may slow more than
expected or stop. If they are making a tight urn
into an alley or driver ray, they may go very slowly.
If pedestrians or other vehicles block them, they
may have to stop on the roadway. Vehicies turning
left may have to stop for oncoming vehicles,
Crivers in Za Hurry. Drivers may feel your
commerciai vehicle 's preventing them from getting
where they want to go on time. Such drivers may
pass you without a safe gap in the oncoming
traffic, cutting {oo close in front of you. Drivers
entering the road may pull ir: front of you in order to
avoid being stuck behind vou, causing you to
brake. Be aware of this and watch for drivers who
are in a hurry.
Impaired Privers. Drivers who are sleepy, have
had too much to drink, are on drugs, or who are ill
are hazards. Some clues to these drivers are:
Weaving across the road or drifting from one side
to another.
Leaving the road (dropping right wheels onto the
shoulder, or bumping across a curb in a turn).
Stopping at the wrong time (stopaing at a green
lignt, or + ‘aiting for too long at a stop).
Open window in cold weather.
Speeding up or siowing down suddenly, driving too
fast or too siow.
Be aiert ‘or drunk drivers and sleepy drivers late at
river Body movement as & Clue. Drivers look in
the direction they are coing to turn. You may
someiimes get a ciue from a driver's head and
body movemenis that & driver tray be going to
make a turn, ever though the turn signals aren't
on. Drivers making over-the-shoulder checks may
be going fo change lanes. These clues are most
easily seen in motorcyclists and bicychsts. Watch
other road users and try to tell whether they might
do something hazardous.
Cor“ticts. You are in conflict when you have to
change speed and/or direction to avoid hitting
someone. Conflicts occur at intersections where
vehicles meet, al merges (such as tunpike cn
ramps) and where there are needed lane changes
(such as the end of a lang, forcing a move to
another lane of traffic). Other situations inciude
slow moving or stallec trafiic in a traffic lane, anc
acciaent scenes. Waich for other drivers who are
in conflict because they are a hazard to you. Wien
they react to this confict, they may do something
that will put them in conflict with you.
2.8.4 ~ Always Have a Flan
You should always be looking for hazards.
Continue ta learn to see nazards on the road,
Haov:ever, dont forget why you are !ooking for the
hazards—they may turn into emergencies. You 100%
for the hazards in order to have time to plan a way
cut of any emergency. When you see & hezard,
think about the emergencies thal could develop
and figure out what you would do. Always be
prepared to take action based on your plans. 'n
this way, you wil be a prepared, defensive driver
who will improve your own safety as well as the
safety of ali road users.
Subsections 2.7 and 2.8
‘Test Your Knowledge
How do you find out how many seconds of
following distance space you have”?
2. If you are driving a 30-foot vehicle al 55
mah, how many seconds of folowing
distance shouid you allow?
3. You should decrease your following
distance i° sorrebody is following you ico
ciosely. True or Falsa?
4. If you swing wide to the left before turning
right, another driver may try to pass you or
the right. True or False”
5. What is a hazard?
5. Why maxe emergency plans when you see
a hazara?
Section 2 — Driving Sefely
Pope 2-25
Comriercis! Driver's License Ma-va;
These questions may be on the test. If you can't
answer them all, re-read subsections 2.7 and 2.8
2,9 — Distracted Driving
Whenever you are driving a vehicle and your
attention is not on the road, you'ie pulling yourself,
your passengers, olner vehices, and pedestrians
in darger. Distracted driving can result when you
perform any activity that may shift you: full
attention from he driving task. Taking your eyes off
the road or hands off the steering wheel presents
obvious driving risks. Menta! activities that take
your ming away from driving are just as dangerous.
Your eyes can gaze at objects in the driving scene
ou! fail to see them because your attention is
distracted elsewnere.
Activities that can disiract your attention include:
talking to passengers; adjusting the radio, CD
player or cimate confrols; eating, drinking or
smoking; reading maps or other fiterature; picking
up something that fell; reading bil'boards and other
road advertisements; watching other people and
vehicles including aggressive drivers; talking on a
cel; phone or CB radio; using telematic devices
(such as navigation systems, pagers, etc.)
daydreaming or being eccupied with otner menta'
2.9.1 — Don’t Drive Distracted
If drivers react a half-second slower because of
distractions, crashes double. Some tips to follow so
you won't become distracted:
Review and be lotaliy familiar with all safety and
usage features on any in-vehicle electronics,
including your wireless or cel! phore, before you
Pre-program radio stations.
Fre-load you favorite CDs or cassette tapes.
Clear the vehicle of any unnecessary objects,
Review maps and plan your route before you begin
Adjust all mirrors “or best all-round visibility before
you start your trip.
Don’t attempt to read oi write while you drive.
Avoid smoking, eating and drinking while you drive.
Dont engage in complex or emoticnaily intense
conversations with other occupants.
2.3.2 — Use In-vahicie Communication
Equipment Cautiously
When possible, pul: off the road in a safe, legal
pace when makingreceiving a call on
conmunication equipment.
if possible, turn ihe cell phone off until your
destination is reached.
Position the cell phone within easy reach.
оге-эгодгат cell phones with commonly called
If you have to place a call, find a safe place to pull
off the road. Do not place a cai! while driving.
Some jurisdictions require that only hands-free
devices can be used while driving. Even these
devices are unsafe to use when you are moving
down the road,
if you must use your cell phone, keep
conversations short. Develop ways to get free of
long-winded friends and associates while on the
road. Never use the cell phone for social visiting,
Hang up in tricky traffic situations.
Do not use the equipment when approaching
locations with heavy traffic, road construction,
heavy pedestriar traffic, or severe weather
Do not attempt to type or read messages on your
satelite system while driving.
Section 2 — Driving Se'ely
Face 7-22
Commercial Driver's License Manual
2.8.5 — Waicir Qui for Other Distracted
You need to bo able to recognize other drivers who
are engaged in any form of driving distraction. Not
recognizing oiher distracted drivers can prevent
you rom perceiving or reacting correctly in time to
prevent a crash. Watch for:
Vehicles that may drift over the lane divider lines or
within their owr lane.
Vehicles traveling at inconsistent speeds.
Drivers who are preoccupied vith maps, food,
cigarettes, cel: phones, or other objects.
Drivers who eppear to be involved in conversations
with their passengers.
Give a distracted driver plenty of room and
maintain your safe ‘o'lowing distance.
Be very careful when passing a driver wo seems
to be distracted. The other driver may not be aware
of your presence, and they may drift in front of you.
4.10 — Aggressive Drivers/Road Rage
2.10.1 What ls 17
Aggressive driving and road rage is not a new
probiern. However, in today's world, where heavy
and siovw-moving traffic and tight schedules are the
norm, more and more drivers are taking out their
anger and frustration in their vehicles.
Crowded roads leave little room for error, leading
to suspicion and hostility among drivers and
encouraging them to take personally the mistakes
of other drivers.
Aggressive driving is the act of operating a motor
vehicle in a selfisn, bold, or pushy manner, without
regard for the rights or safety of others.
Road rage is operating a motor vehicle with the
intent of doing harm to others or physically
assaulting a driver or ther vehicle,
2.70.2 ~ Don’t Be an Aggressive Driver
How you fee: before you even star: your vehicle
has a [ot to do with how stress will affect you while
Give the drive your full attention. Don't aitou:
yourself to vecome distracied by talking on your
cell phone, eating, etc.
Be realistic about your travel time, Expect delays
because of traffic, construction, or bad weather
and make añowances.
If youre going to be :ater than you expected — deal
with it. Take a deen breaih and accept the delay.
Give other drivers the benefit of the doubt. Try to
imagine wny he or she is driving thai way.
Whatever their reason, it has rothing to do with
Slow down and keep your folowing distance
Don’t drive slowly in the left lane of trafic,
Avoid gestures. Keep vou hands on the wheel
Avoid making any gesiures that might anger
another driver, even seemingly harmless
expressions of irritation like shaking your head.
Be a cautious and courteous driver. if another
driver seems eager to get in front of you, say, Be
my guest.” This response will soon become a habii
and you won't be as offended by other drivers’
2.10.5 - What You Should De When
Contronted by ar: Agaressive Driver
First and foremost, make every attempt to get out
of their way.
Put your pride in the bac seat Do not chailenge
them by speeding up or attempting to hold-your-
own in your iravel lane.
Avoid eye contact.
Ignove gestures and refese to react to them.
Report aggressive drivers to the appropriate
authorities by providing a vehicle cescription,
icense number, ¡ocaton and, if possible, dreciion
of travel.
if you have a cell phone, and can do it safely, call
the police.
if an aggressive driver is involved in a crash farther
down the road. stop a safe distance from the crash
scene, wait for the police to arrive, and report the
driving behavior that you witnessed.
Subsectons 2.9 anc 2.50
Test Your Kriow:iedge
1. What ere some tips to follow so you won"
Reduce your siress before and while you drive. become a distracted driver?
Listen to “easy listening” music. e How do yo! use = invericie
communications equipment cautiousiy?
3. How do you recognize a disiracted driver?
Page 2-23
Section Z — Driving Safely
vommercial Driver's License Manual
4, What is the difference between aggressive
driving and road rage?
5. What should you do when confrontad with
an aggressive driver?
6. What are some things you can do to
recuce your stress before and while you
These questions may be on the test. If you can't
answer them all, re-read subsections 2.9 and 2.10.
== — === Lx |
2.11 — Driving at Night
2.11.1 — Its More Dangerous
You are at greater risk when you drive at nigat.
Drivers can’t see hazards as quickly as in daylight,
so they have less time lo respond, Drivers caught
by surprise are less able to avoid a crash.
The prodiems of night driving involve the driver, the
roadway, and the vehicle.
=. 11,4 — Driver Factors
Vision. People can't see as sherply at night or in
aim light. Also, their eyes reed time to adjust to
seeing in dim light. Most people have noticed this
when warking into a dark movie theater.
Giare. Drivers can be bliaded for a short time by
brignt lignt. It takes time to recover from this
blindness. Older drivers are especizily bothered by
glare. Most people have been temporarily blinded
by camera fiash units or by the high beams of an
oncoming vehicie. it can take several seconds to
recover from glare. Even wo seconds of glare
biirdness can be dangerous. À vehicie going 55
mph will travel more than half the distance of a
foctbal: field during that time. Don't look directiy at
bright lights when driving. Look at the right side of
the road. Watch the sidelines when someone
coming toward you has very bright lights on.
Fatigue and Lack of Alertness. Fatigue (being
dred) and lack of aleríness are bigger problems at
night. rhe body's need ‘or sleep is beyond a
person's control. Most people are less alert at
night, especially after midnight. This is particulary
‘rue if you heve been driving for a long time.
Drivers may not see hazards as soon, or react as
quickly, so the chance of a crash is greater. if you
are sl2epy, the only safe cure is to get off the road
and get some sleep. li you don't, you risk your life
and tne lives of otners,
2.11.3 — Roadway Faciors
Poor Lighting. In the daytime there is usually
enough light to see weli. This is not true at night.
Some areas may have brignt street lights, tut
many areas wi! have poor lighting. Or mos! roads
you wil probably have to depend entireiy on your
Less light means you will not bz able to see
hazards as weli as 'n daytime. Road users who do
not have lights are hard to see. There are many
accidents at right involving pedestrians, joggers,
bicyclists, and animals.
Even when there are lights, the road scene can be
confusing. Traffic signals and hazards can be herd
to see against a background of signs, shop
windows, and other lights.
Drive slower when lighting is poor or confusing.
Drive slowly enough io be sure you can stop in the
distance you can see ahead.
Jrunk Drivers. Drunk drivers and drivers under
the irfluence of drugs are a hazard to themselves
and to you. Be especially alert around the closing
times for bars and taverns. Waich for drivers who
have trouble staying in their lane or maintaining
speed, who stop without reason, or show other
signs of being under the influence of alcohol or
2.11.4 — Vehicle Factors
Headlights. At night your headlights will usually be
the main source of light for you to sec by and for
others to see you. You can't see nearly as much
with your headlights as you see 'n the daytime.
With low beams you can see ahead abou! 250 feet
and with high beams aboui 350-500 feel. You must
adjust your speed to keep your stopping distarce
within your sight distance. This means going siov.iy
enough to be able to stop within the range of your
headlights. Other ise, by the time you see a
hazard, you will not have time to stop.
Night driving can be more dangerous if you have
probers with your headiignis. Dirty headlights
may give only half the light they should. This cuts
down your ability io see, and makes it harder for
others to see you. Maite sure your lights are clean
ard workirg. Headiights can be out of adjusiment.
if they don't point in the right direction, they won't
give you a good view ard they car blind other
drivers. Have a quaiified person make sure they
are adjusted properly.
Section 2 — Driving Safely
rage 2-24
Commercial Driver's License Manual
Other Lights. In order for you to be seen easily,
the following must be clean and working properly:
Marker lichts.
C.earance lights.
Identification lights,
Turn Signals and Eralte Lights. At night your turn
signals and braxe lights are sven more important
for telling other arivers what you intend to do. Make
sure you have clean, working turn signals and stop
Windshicld and Mirrors. It is more important at
night than in ithe daytime to have a clean
windshield and clean mirrors. Bright lights at night
can cause dirt on your windshield or mirrors to
create a glare of is own, blocking your view. Viost
people have experienced driving toward the sun
just as it has risen or is about to set, and found that
they can barely see through a windshieid that
seemed to look OK in the middie of the day. Clean
your windshield on the inside and outside for safe
oriving at night.
2.11.5 ~ idight Driving Procedures
Pre-trip Procedures. lake sure you are rested
and alert. If you are drowsy, sleep before you
drive: Even a nap can save your life or the lives of
others. if vou wear eyeglasses, make sure they are
ciean and unscra:ched. Dont wear sunglasses at
nignt. Do a complete pre-trip inspection of your
vehicle. Pay attention to checking all lights and
refiectors, and cleaning those you can reach.
Avoid Blinding Others. Glare from your
headlights can cause problems for drivers coming
toward you. They can also bother drivers going in
the same direction you are, +:hen your lights shine
in their rearview mirrors. Dim your lights before
they cause glare for other drivers. Dim your lights
within 500 feet of an oncoming vehicle anu when
follovirg another vehicie within 500 feet.
Avola Glare from Oncoming Vehicles. Do not
iook direclly at lights of oncoming vehicies, Look
slightly to the right at a right lane or edge marking,
ii available. II other drivers don’t put their low
heams on, don't try to “get back ai them” by putting
your own high beams cn. This increases glare for
oncoming divers and increases the chance of a
Use High Beams When You Can. Some drivers
make the mistake of always using low beams. This
seriously cuts down on their ability to see ahead.
Jse high beams when it is saïe and legal! to do so.
Use them when you are not within 500 feet of an
approaching vehicle. Also, don't lel the insice of
your cab get too bright. This makes it harder to see
outside. Xcep the interior light off, ana adjust your
instrument lights as lov: as you can to stil be able
to read the gauges.
Н You Get Sleepy, Stop at the Nearest Safe
Place. Peopie often don't iealize how close they
are to faling asleep even when their eyel‘ds are
falling shill. if you can safely do so, look at yourself
in a mirror. if you look seedy, or you just feel
sleepy, stop driving! You are in a very dangerous
condition, The only safe cure is to sleep.
217 -- Criving in Fog
Fog can occur at any time. Fog on highways can
be extremely dangerous, Fog is often unexpected,
and visibility can deteriorate rapidly. Yot: should
watch for foggy conditions and be ready io reduce
your speed. Jo not assume thal the fog wil thin
out after you enter it.
The best advice for driving in fog is don't. It is
preferabie that you pub off the road into à rest area
or truck stop until visibility is better, M you must
drive, be sure to consider the following:
Obey all fog-related warning signs.
Slow down before you enter fog.
Use low-beam headlights and fog lights for best
visibility even in daytime, and be alert for other
drivers who may have forgotten to turn on their
Tur on your 4-way Jlashers. 7 his will give vehicies
approaching you from behind a quicker opportunity
to notice your vehicle.
Watch for vehicles on the side of the roadway.
Seeing taillights or headlights in front of you may
not be a true indication of where the road is ahead
of you. The vehicle may not be on the road at all.
Use roauside highway reflectors as guides io
aelermine how the road may curve ahead of you.
Listen for traffic you cannot see,
Avoid passing other vehicies.
Dont stop along the side of the roed, unless
ehsolulely necessary.
2.13 ~ Diving in Winder
2.15.1 ~ Vshicle Checks
Section 7 — Driving Safely
Page 2-25
Commerciai Driver's Lisense Manual
Make sure your vehicle is ready before driving in
winter weather. You should make a regular pre-trip
inspection, paying extra attention to the following
Coclant Level and Antirreeze Amount. Make
sure ihe cooling system is full and there 's enough
antifreeze in the sysiem to protect against freezing.
This can be checked wiih a special coolant tester.
Defrosiing and Heating Equipment. Make sure
the defrosters work. They are needed for safe
driving. Make sure the heater is working, and that
you know how to operaie it. If you use other
heaters and expect to need them (e.g., mirror
heaters, battery box heaters, fuel tank heaters),
check their operation.
Wipers and Washers. Make sure the windshield
wiper blades are in good condition. Make sure the
wiper blades press against lhe window hard
enough to wipe the windshield clean, otherwise
they may not sweep off snow properly. Make sure
the windshield washer works and there is washing
fluid in the washer reservoir.
Use windshield washer antifreeze to prevent
freezing of the washer liquid. If you can't see well
enough while driving (for example, 1 your wipers
fail), siop safely and iix the problem.
Tires, Make sure you have enough tread on your
tres. The drive tires must provide fraction to push
the rig over wet pavement and through snow. The
steering tires must have traction to steer the
vehicle. Enough tread is especially important in
winter conditions. You must have at least 4/32 inch
tread depth in every maior groove on front tires
and at least 2/32 inci: on other tires. More woud
»e better. Use a gauge to determine if you have
enough tread for safe driving.
Tire Chains. You may find yourself in conditions
where you can't drive without cnains, even to get to
a place of safety. Carry tre right number of chains
and extra cross-iinks. Make sure they will fit your
drive tires. Check the chains for broken hooks,
worn or broken cross-links, and bent or broken
side chains. Lear: how to put the chains on before
you need to de it in snow and ice.
Lights and Refleciors, Make sure the lights and
refleciors are clean. iighis and reflectors are
especially importa during bad weather. Check
from time to time during had weather to make sure
they aie clean and working properly.
Windows and Mirrors, Remove any ice, snow,
etc., from the windshield, windows, and mirrors
before starting. Use a windshield scraper, snow
brush, and windshield defroster as necessary.
Hand Holds, Steps, and Deck Plates. Remove all
ice and snow from hand holds, steps, and deck
Hates. This wili reduce the denger of slipping.
Radiator Shutters and Winterfroni. Remove ice
for: the radiator shuiters. Make sure the
winterfront is not closed too tightly. If the shutters
{сете shut or the winterfront is closed too much,
the engine may overheat and stop.
Exhetist System. Exhaust system leaks are
especially dangerous when cab ventilation may be
poor (windows rolled up, etc.). Loose conneciions
could permit poisonous carbon monoxide fo leak
into your vehicle. Carbon monoxide gas will cause
you to be sleepy. In large enough amounts it can
«ill you. Check the exhaust system ior icose parts
and for sounds and signs of leaks.
£.732.2— Driving
SiHopery Surfaces. Drive slowly and smoothly on
slippery roads. IU it is very slippery, you shouldn't
drive at all. Stop at the first safe place.
Start Cently and Slowly. When first starting, се!
tha feel of the road. Don't hurry.
Check for Ice. Check for ice on the road,
especially bridges anu overpasses. A lack of spray
from other vehicles indicates ice has formed on the
road. Also, checx your mirrors anc wiper blades for
ice. If they have ice, the road most likely will be icy
as weil,
Adiusi Turning and Braking fo Conditions.
Make turns as gently as possible. Don't brake any
harder than necessary, and don’t use the engine
brake or speed retarder. (They can cause the
driving wheels to skid cn slippery surfaces. }
Adjust Speed to Conditions. Don't pass slower
venicies unless necessary. Go slowly and waich
far enough ahead to keep ú stcady speed. Avola
having .0 siow down and speed un. Take curves at
slower speeds and don't brake while in curves. Be
aware that as the isnperature rises to the point
where ice begins to melt, the road becomes even
more slippery. Slow town move.
adjust “pace io Conditions. Dont drive
alongside other vehicles. Keep a longer following
Sectien 2 — Criving Sarziy
Page 2-26
Commercia: Driver's License Manuar
distance. When you see a traffic jam ahead, slow
down or stop to wait for it to clear, Try hard to
anticipate stops early and siow down gradually.
Watch for snowplows, as well as sait and sand
trucks, and give them plenty of room.
Wet Brakes. When driving in heavy rain or deep
standing water, your brakes wili get wet. Water in
the brakes can cause the brakes to be weak, to
apply unevenly, or to grab. This can cause lack of
braking povser, wheel lockups, pulling to one side
or the other, and jackknife if you pull a trailer.
Avoid driving through deep puddles or fiowing
water if nossibie. If not, you should:
Slow down and place transmission in a low gear.
Gently put on the brakes. This presses linings
against brake drums or discs and keeps mud, silt,
sand, and water from: getting in.
Increase engine rpm and cross the water while
keeping light pressure on the brakes.
When out of the water, maintain light pressure on
the brakes for a short distance to heat them up and
dry them out.
Make a test ston when safe to do so. Check
behind to make sure no one is following, then
apply the brakes to be sure they work weil. if noi,
cry them out further as described above.
(CAUTION: Do not apply too much brake pressure
and accelerator at ine same time, or you can
overheat orake drums and linings.)
2.44 — Driving in Very Hot Weather
2.14.1 — Vehicle Checks
Do a normal pre-trip inspection, but pay special
attention to the folowing items.
Tires. Check the tire mounting and aii pressure.
inspec. the tires every two nours or every 100
mies when driving in very hot weather. Air
pressure increases with temperature. Do not let air
out or the pressure will be too low when the tires
coo! off. if a tire is too not to touch, remain stopped
unii’ the tire cools off. Otherwise the tire may blow
out or catch fire,
Engine Oi:. The engine oil helps keep the engine
cool, as well as lubricating +. Make sure there is
enough ercire oil. if you have an ol temperatures
gauge, make sure the tempereture is within the
proper range while you are driving.
Frgine Toolant. Before starting out, mare sure
the ei:gine cooling system nas enough water and
Section 2 — Driving Sarely
antifreeze according to the engine manufacturer's
directions. (Antifreeze helps the engine under not
conditions as well as cold conditions.) When
criving, check the water temperature or coolant
emperature gauge from time to time. Make sure
that it remains in the normai range. If the gauge
goes above the highest safe temperature, there
may be something wrong that could lead to engine
failure and possibly fire. Stop driving as soon as
safely possible and try to find out what is wrong.
Some vehicles have sight glasses, see-through
coolart overflow containers, or coolant recovery
containers. These permit you to check the coclant
leve! v.hile the engine is hot. if the container is not
part of the pressurized system, the cap can be
safely removed and coolant added even when the
engine is at operating temperature.
Never remove the radiator cap or any part of the
pressurized system until the system has cooed.
Steam and boiling water can spray urder pressure
and cause severe burns. if you can touch the
radiator cap with your bare hand, it is probadly cool
enough to open.
I¥ coolant has to be added to a system without a
recovery tank or overflow tani, follow hese steps:
Shut engine off.
Wait until engine has coolec.
Protect hands {use gloves or a thick cloth).
Turn radiator cap slowly to the first stop, which
releases the pressure seal.
Step back while pressure is released rom cooling
When all pressure has been released, press down
on the cap anc turn it further to remove it.
Visually check level ¢f coolant and add more
coolant if necessary.
Replace cap and turn all the way to the closed
Engine Belts. Learn how to check v-belf tightness
on your vehicle by aressing ar the belts. Loose
belts will not turn the water pump and/or fan
properly. This will resuii in overheating. Also, check
be'ts for cracking or other signs of wear.
Hoses. Make sure coolant hoses are in good
condition. A broken hose while driving car icad to
engine failure and ever: fire.
2.44.2 — Driving
Waich for Bieeaing Tar. Tar in the road pavemert
frequently rises Lo the surface in very hot weather.
Page 2-27
Commercial Driver's License Manual
Spots where tar "bleeds” to the surface are very
Go Slowly Enough to Prevent Overheating.
High speeds create more heat for tires and the
engine. In desert conditions the heat may build up
to the point where it is dangerous. The heat will
increase chances of tire failure or even fire, and
engine failure.
Subsections 2.11, 2.12, 2.13, and 2.14
Test Your Knowledge
1. You should use low beams whenever you
can. True or False?
What should you do before you drive if you
are drowsy?
What effects can wet brakes cause? How
can you avoid these problems?
You should let air out of hot tires so the
pressure goes back to normal. True or
5. You can safely remove the radiator cap as
long as the engine isn’t overheated. True
or False?
кое N
These questions may be on the test. If you can't
answer all of them, re-read subsections 2.11, 2.12,
2.13, and 2.14.
2.15 — Railroad-highway Crossings
Railroad-highway grade crossings are a special
kind of intersection where the roadway crosses
train tracks. These crossings are always
dangerous. Every such crossing must be
approached with the expectation that a train is
2.15.1 — Types of Crossings
Passive Crossings. This type of crossing does
not have any type of traffic control device. The
decision to stop or proceed rests entirely in your
hands. Passive crossings require you to recognize
the crossing, search for any train using the tracks
and decide if there is sufficient clear space to cross
safely. Passive crossings have yellow circular
advance warning signs, pavement markings and
crossbucks to assist you in recognizing a crossing.
Active Crossings. This type of crossing has a
traffic control device installed at the crossing to
regulate traffic at the crossing. These active
devices include flashing red lights, with or without
bells and flashing red lights with bells and gates.
2.15.2 -~ Warning Signs and Devices
Advance Warning Signs. The round, black-on-
yellow warning sign is placed ahead of a public
railroad-highway crossing. The advance warning
sign tells you to slow down, look and listen for the
train, and be prepared to stop at the tracks if a train
is coming. See Figure 2.15.
Pavement Markings. Pavement markings mean
the same as the advance warning sign. They
consist of an “X” with the letters “RR” and a no-
passing marking on two-lane roads. See Figure
Figure 2.15
Section 2 — Driving Safely
Page 2-28
Commercial Driver's License Manual
Figure 2.16
There is also a no passing zone sign on two-lana
roads. There may be a white stop line painted on
the pavement before the railroad tracks. The front
of the school bus must remain behind this line
while stopped at the crossing.
Crossbuck Signs. This sign marks the grade
crossing. It requires you to yield the right-of-way to
the train. If there is no white line painted on the
pavement, you must stop the bus before the
crosshuck sign. When the road crosses over more
than one set of tracks, a sign below the crossbuck
indicates the number of tracks. See Figure 2.17.
Figure 2.17
Flashing Red Light Signals. At many highway-
rail grade crossings, the crossbuck sign has
flashing red lights and bells, When the lights begin
to flash, stop! A train is approaching. You are
required to yield the right-of-way to the train. If
there is more than one track, make sure all tracks
are clear before crossing. See Figure 2.18.
Gates. Many railroad-highway crossings have
gates with flashing red lights and bells. Stop when
the lights begin to flash and before the gate lowers
across the road lane. Remain stopped until the
gates go up and the lights have stopped flashing.
Proceed when it is safe. See Figure 2.18.
Bi re a вы о
Figure 2.18
2.15.3 — Driving Procedures
Never Race a Train to a Crossing. Never attempt
to race a train to a crossing. It is extremely difficult
to judge the speed of an approaching train.
Reduce Speed. Speed must be reduced in
accordance with your ability to see approaching
trains in any direction, and speed must be held to a
point which will permit you to stop short of the
tracks in case a stop is necessary.
Don't Expect to Hear a Train. Because of noise
inside your vehicle, you cannot expect to hear the
train hom until the train is dangerously close to the
Don't Rely on Signals. You should not rely solely
upon the presence of warning signals, gates, or
flagmen to warn of the approach of trains. Be
especially alert at crossings that do not have gates
or flashing red light signals.
Section 2 - Driving Safely
Page 2-28
Cormmerc.a: Driver's License Manual
Doubie Tracks Require ¿2 Done Check.
Remember that a train on one track may nide a
train on the other track. Loox both ways pefore
crossing. After one rain has cleared a crossing, be
sure no other trains are rear before starting across
the tracks.
Yard Areas and Grade Crossings 'n Cities and
Towne, Yard areas and grade crossings .n cities
and towns are just as dangerous as rural grade
crossings. Approach then with as much caution.
2.15.4 — Stopping Safelv at Ratiroac-
righway Crossings
A fu: stop is requiied at grade crossings whenever:
The nature of the cargo makes a stop mandatory
under state or federal regulations.
Such a stop is otherwise required by law.
When stopping be sure to:
Check for traffic behind you while stooping
gradualiy. Use a pullout lane, if available.
Turn on your four-way emergency flashers,
2.15.5 ~ Crossing the Tracks
Railroad crossings with steep approaches can
cause your unif to hang up on the tracks.
Never permit traffic congitions to trap you т а
position where you have to stop on the tracks. Be
sure you can get all the way across the tracks
before you start across. It takes a typical tractor-
trailer unit at least 14 seconds io clear a single
track and more than 15 seconds to clear a double
Do not shift gears while crossing railroad tracks.
Z.15.€ — Special Situations
Be Aware! These irailers can get stuck on raised
Low slung units (owboy, car carrier, van,
nossum-belly livestock trailer).
Singie-axle fractor pulling a wong trailer with its
landing gear set to accommodate a tancem-ax.e
f for any reason you get stuck on the tracks, get
out of the vehicle and away from the tracks. Check
signposts or signal housing at the crossing for
emergercy notificatic: information. Call 911 о;
other emergency number. Give the location of the
crossing using ail identifiable landmarks, especially
the DOT number, If posted.
2,16 - Mountain Driving
in mountain driving, gravity plays a major role. On
any upgrade, gravity slows you down. The steeper
the grade the longer the grade, and/or the heavier
the load-the more you will have to use lowe gears
to climb nills or mountains. In coming down long,
steep cowngrades, gravity causes the speec of
your vehicle id increase. You must seleci an
appropriate sa’e speed, then use a low gear, and
proper braking techniques. You should plan ahead
and obtain information about any long, sieep
grades along ycur planned route of iravel. ff
possible, talk to other drivers who are familiar witn
the grades to find out what speeds are safe.
You must go slovdy enough so your brakes can
hold you back thout getting too hot. If the brakes
become too hot, they may start to “fade.” This
means you have to apply ther harder and harder
to get the same stopping power. you continue 0
use the brakes hara they can keep fading unt’l you
cannot slow down or stop at all.
2.16.7 — Select & “Safe” Speed
Your most imporiant consideration is to select a
speed that is rot too fast for the:
Total weight of the vehicle and cargo.
Length of the grade.
Steepness of the grade,
Road conditions.
fa speed limit is posted, or there is a sign
indicating “Maximum Safe Speed,” never exceed
the speed shown. Also, iook for ana heed warning
signs indicating the length and steepness of the
You must use the braking effect of the engine as
the principal way of controlling your speeu. The
braking effect of the engine is greatest when it is
near the governed roms and the transmission is in
‘ле ower gears. Save your braxes so you vi be
able to slow or stop as required by road and traffic
Sacton 2 — Driving Sara:
Page 2-30
Commercial Driver's License Manual
2.76.2 — Select the Right Gear Before
Starting Down the Grade
Shift the transmission to a low gear before starting
down the grade. Do not try to downshift after your
speed has already buiit up. You wili not be abie to
shift into a lower gear. You may not even be able
to get back inio any gear anc ail engine braking
effect will be lost. Forcing an automatic
transmission intc a lower gear at high speed could
damage the transmission and also lead to loss of
all engine braking effect.
With oder trucks, a rule for choosing gears is fo
use the same gear gong down a hill that you
would need to climb the hill. However, new trucks
have low friction parts and streamlined shapes for
fuel economy. They may also have more powerful
engines. This means they can go up hills in higher
gears and have less friction and air drag io hold
them back going down hills. For that reason,
drivers of modern trucks may have to use lower
gears going down a hill than would be required to
go up the hill. You should know what is right for
your venicie.
2.16.3 — Brake Fading or Failure
Brakes are designed so brake shoes or pads rub
against the brake drum or disks to slow the vehicle.
Braking creates heat, but brakes are desighet to
take a lot of heat. However, brakes can fade or fal
from excessive heat caused by using them too
much end not relying on the engine braking effect.
Brake fade is also affected by adjustment. To
safely control a vehicle, every brake must do its
share of the work. Brakes out of adustment will
stop doing their share before those that are in
acjustment, The ofher brakes can then overheat
and fade, and there will not pe enough braking
available to contro: the vehicle. Brakes can get out
of adjusiment quickly, especially when they are
used a fot; also, brake linings wear faster when
they are hot. Therefore, brake adjustment must be
checked freguently.
2.76.4 Proper Braking Techrique
Remember, The use of brakes on a long and/or
steep cowngrade is only a supp:ement to the
braking effect of the engine. Once ¡he vehicle is in
the proper :0v gear, tire following are the proper
breking techniques:
Apaly the brakes just hard enough to Tee! a ceiirite
When your speed has been reduced fo
approximately five mph below your "safe sneed,
release ¡he brakes. (This brake application should
last for about three seconds.)
When your speed has increased to vou” “safe”
speed, repeat steps 1 and 2.
ror example, if your "safe” speed is 40 mph, you
would not apply the brakes unil your speed
reaches 40 mph. You row apply the brakes nard
enough to gradually reduce your speed to 35 mn?
and then release the brakes. Repeat this as often
as necessary until you have reached the and of tre
escape ramps have been built on many steep
mountain do.xngraces. Escape ramps are mae to
stop runaway vehicles safely without inivring
crivers and passengers. Escape ramps use a “ong
рей of loose, soft material to slow a runaway
vehicle, sometimes in combination with an
Know escape ramp locations on your route. Signs
snov drivers where ramp are ocated. Escape
ramps save lives, equipment and cargo.
Subsections 2.15 and 2.15
Test Your Knowledge
4 What factors determine your se:ection of =
“safe” speed when going down a long,
steep downgrade?
2. Why should you be in the proper gear
before starting down a hill?
3. Describe the proper braking technique
when going down a ong, steep
4, What type of vehicles can get stuck on a
rairoad-nighway crossing?
5. How long does it take for a typical tracto:-
trailer unit to clear a doubre traci?
These questions may be on the test. If you can't
answer them all, re-read sdJbsections 2.15 and
a "Ni ia a ini e —]—]—— —
—— “PB AAR ci
Section 2 — Driving Safely
Page 7-4:
Conimercial Driver's License ifanual
2.47 — Driving Emergencies
Traffic emergencies occur when two vehicles are
about to collide. Vehicle emergencies occur when
tires, brakes, or other critical paris fai. Following
the safety practices in this manual cen help
prevent emergencies. But if an emergency does
happen, your chances of avoiding a crash depend
unon how well you laxe action. Actions you can
take are discussed below.
2.17.57 — Steering to Avoid a Crash
Stopping is not always the safest thing to do in an
emergency. When you don't have enough room to
stop, you may have to steer away from what's
aheed. Remember, yot: can aimost always turn to
miss an cbstacie more quickly than you can stop.
(Hov.ever, top-heavy vehicles and tractors with
multiple trailers may flip over.)
Keep Both Hands on the Steering Wheel. In
order to turn quickly, you must have a firm grip on
the steering whee! witn both hands. The best way
to have both hands on the wheel, if there is an
emergency, is to keep triem there ail the time.
How to Turn Quickiv and Safalv. À quick turn
can be made safely, if it's done the rignt way. Here
are some points that safe drivers use:
Do not apply the brake while you are turning. It's
very easy to lock your wheels while turning. If that
happens, you may skid out of control.
Do not turn any more than needed to clear
whatever is in your way. The more sharply you
turn, the grealer the chances of a skid or rollover.
Be prepared to "countersteer,” tha! is, to turn the
wheel back in the other direction. once youve
passed whatever was in your path. Unless you are
prepared to countersieer, you won't be able to do it
quickly enough. You should think of emergency
steering and countersieering as two paris of one
driving action.
Where to Steer. If an oncoming driver has drifted
into your lane, a move to your right is best. If that
driver rea:izes what nas happened, tie natural
response will be to return to his or her own lane.
If something is blocking your path, the best
direction to steer will depend on the situation.
H you have been using your mirrors, you'll know
which lane is empty and can be safely used.
f the shoulder is clear, going right may be best. No
one is likely to be driving on the shouder but
someone may be passing you on the left. You will
know if you have been using your mirrors.
If you are blocked on both sides, a move to the
right may be best. Af ieast you won't force anyone
into an opposing traffic lane and a possible heed-
on colision.
Leaving ihe Road. In some emergencies, you
may have to drive off the road. It may be ess risky
than facing a coilision with another vehicle.
Most shoulders are strong enough to support the
weign! of a large venicle and, therefore, offer an
aveilable escape route. Here are some guidelines,
if you do leave [e mad.
Avoid Braking, :f possible, avoid using the brakes
unt your speed has dropped to about 20 mph.
Ther brake very gently to avoid skidding on 2
foose surface.
Keep Cne Set of Wheels on the Pavemant, if
Possible. This helps ta maintain contre!
Stay on the Shoulder. If the shoulder is clear,
stay on it until your vehicle has come to a stop.
Signal and check your mirrors before pulling back
onto the road.
Returning to the Read. If you are forced to return
to the road befcre you can stop, use the foliowing
Hold the wheel lightly and turn sharply enough to
get right back on the road safely. Don't try to edge
graduaily back on the road. f you do, your tires
might grab unexpectedly and you could lose
When both front tires are cn tne paved surface,
countersteer immediately. The two turns should be
made as a single “steer-countersiesr” move.
2.77.2 - How to Stop Quickly and Safely
If somebody suddeniy pulls out in front of you, your
natural response is to hit the brakes. This is a good
response if there's enough distance to stop, and
you use the brakes correcily.
You should breke in a way that will keep your
vehicle in a straight line end allow you to turn if it
becomes necessary. You can use the “controlled
braking” method or the "stab braking” method.
Controlled Braking. With this method, you apply
tne brakes as hard as you cen without iocking the
wheels. Keep sicerirg whee! movements very
Sectior 2 — Driving Sarely
Page 2-37
Commercial Drives License Manual
sma white doing this. If you need to make a larger
steering acjustment or if the wheels lock, release
the brakes. Re-apply the brakes as soon as you
Sian Braking
Apply your brakes all the way.
Release brakes when wheels lock up.
As soon as the wheels start rolling, apply the
brakes fully again. (it car take up to one second
for the wheels to start rolling after you release the
brakes. If you re-annly ithe brakes before the
wheels siart rolling, the vehicle won't straighten
Cont Jam on the Brakes. Emergency braking
does not mean pushing down on the brake pedal
as hard as you can. That wili only keep the wheels
locked up and cause a skid. If the wheels ere
skidding, vou cannot control the vehicie.
2.17.3 — Brake Failure
Brakes хер! in good condition rarely fail. Most
hydraulic brake faiures occur for one of two
reasons: {Air brakes are discussed in Section 5.)
Loss of hydrauiic pressure.
Brake fade on long hills.
Loss of Hydraulic Pressure. When the system
won't build up pressure, the brake pecal will feel
spongy or go to the floor. Here are some things
you can do.
Dovrshift. Putting the vehicle into a lower gear
will help to siow the vehicle.
Pump the Eirakes. Sometimes pumoirg the brake
pedal will generate enough hydraulic pressure to
stop the vehicle.
Use the Parking Brake, The parking or
emergency brake is separate from the nydraulic
brake system. Therefore, it can be used to slow tre
vehicle. However, be sure to press the release
button or pull the release lever al the same time
you use the emergency brake so you can adiust
the brake pressure znd keep the wheels from
tocking Lp.
Finc an Sscape Route. While slowing the vehicle,
look for an escape route—an oper field, side street,
or escape ramp. Turning uphill is a good way to
siow and siop the vehicle. Make sure the vehicle
does ro! star: rolling backward after you stop. Put
it in low gear, apply the narking brake, and, if
necessary, rol back into some obstacle that will
ston the vehicle,
trake Farure con Downgrades. Going slow
enough and braking properly will almost always
prevent braka failure on long downgrades. Once
the brakes have fziled, however, you are going to
have to lock outside your vehicle for something to
stop it.
Your best hope is an escape ramp. If there is one,
there'll be signs tsiling you about it. Use it. Ramns
are usually localed a few miles from the top of the
downgrade. Every year, hundreds ot drivers avoid
injury to themselves or damage to their vehicles by
using escape ramps. Some escapa ramps use soft
gravel that resisis tie motion of the venicle and
brings it to a stop. Others ‘urn uphill, using the hiil
to stop the vehicle end soft gravel to hold it in
Any driver who loses brakes going downhill should
use an escape ramp if it's available. If you don't
use it, your chances of having a serious crash may
be much greater,
if no escane ramp is available, teke fhe leasi
hazardous escape route you can-such as an oper:
feld or a side road that fisttens out or turns uphil’.
Make the move as soon as you know your brakes
dont work. The longer vou wail, the faster the
vehicle will go, and the harder it will be to stop.
2.17.4 Tire Feiiure
Recognize Tire Tailure. Quickly knowing you
have a tire failure will let you have more time to
react. Having just a few exta seconds to
remember what it is you're supposed to do can
help you. The major signs of tire failure are:
Sound. The loud “bang” of a biowout is an easily
recognized sign. Because it car take a few
seconds for your vehicle to react, you might think it
was some other vehicle. But any time you hear a
tire blow, you'd be safest to assume it is yours.
Vibration, If the vehicle thumps or vibrates haavily,
К may de a sign thal one of the tires has gone fiat.
With a rear tire, that may be the only sign you get.
Feel. If the steering feels “heavy,” it is probably a
sign that one of the front tires has failed.
Sometimes, failure cl a rear tire will cause the
vehicie to s:ide back and foth o: “fishtail
cdowever, duel rear tires usually prevent this.
Section 2 — Driving Safely
Page 2-33
Commercial Drive:'s License Manuva
Respond to Tire Failure. When a tire fails, your
vehicle is in danger. You must immediately:
Hold the Steering Wheel Firmiy. if a front tire fails,
fi can twist the steering wheel out of vour hand.
The only way to prevent this is to keep a firm grin
on the steering wheel with both hands at all times.
Stay Off the Brake. ¡ts natural to want to brake in
an emergency. However, braking when a tire has
fai'led could cause loss of control, Uniess you're
about to run into something. stay off the brane until
the vehicle has slowed down. Then brake very
gently, puil off the road, and stop.
Check the Tires. After you've core 0 a stop, get
out anc check all the tires, Do this even if the
vehicle seems to be handling all right. if one of
your dual fires goes, the only way you may know it
is by cetting out and looking at it.
£.18 — Antilock Braking Systems (ABS)
ABS is a comouterized system that keeps your
wheels from locking up during hard brake
ABS is an addition to your normal brakes. it does
not decrease or increase your normal braking
capability. ABS only activates when wheels are
about to lock up.
ABS does not necessarily shorten your stooping
distance, but it does help you keep the vehicle
under contro! during hard braking.
2.18.1 — How Anfilock Braking Systems
Sensors detect potential wheel lock up. Ап
electronic control unit (ECU) will then decrease
brake pressure 10 avoid wheel lockup.
Brake pressure is adjusted fo provide the
maximum braking without danger of lockup.
ABS works far faster than the driver can respond to
potential whee! lockup. At all other times the brake
system will operale normally.
2.18.2 - Vehicles Required to Have
Arnitifock Braking Systems
The Department of Transportation requires thai
ABS be on:
Truck tractors with air brekes buiit on or after
Merch 1, 1997.
Other air brake vehicles, (trucks, buses, trailers,
and converter collies) built on or after March 1,
Hydraulically braked trucks and buses with a gross
vehicle weight rating of 10,000 Ibs or more built on
or after March 1, 1999.
Many commercial vehicles built before these dates
have been voluniarily equipped with ABS.
2.18.3 -- How tc Know If Your Vehicle is
Lguipped with ABE
Tractors, trucks, and buses will have yellow ABS
malfunction lamps on the instrument panel.
Trailers will have yellow ABS malfunction lamps on
the left side, either on the front ar rear corner.
Dollies manufactured on or after ¡arch 1, 1998,
are required to have a lamp on the let side.
As a system check on newer vehicles, the
malfunction lamp comes on at start-up for a bulb
check, and then goes out quickly. On older
systems, the lamp could stay on until you are
driving over five mph.
T the lamp stays on after the buib check, or goes
0 once you arc under way, you may have ¡ost
ADS control.
In the case of towed units manufactured before it
was required by the Department of Transportation,
it may be difficult to tell if the unit is equipped wii
ABS. Look under the vehicle for the ECU and
wheel speed sensor wires coming from the back of
the brakes.
&. 78.4 - How ABS Helps You
When you brake hard on slippery surfaces in a
vehic:e without ABS, your wheels may lock up.
When your steering wasels lock up, you lose
steering control. When your other wheels lock up,
yot: may srid, jackknife, or even spin the vehicle.
ABS helps you avoid wheel lock up and maintain
control. You may or may not be able to stop faster
with ABS, but you should be able to steer around
an obstacle whiie braking. anc avoid skids caused
by over braking.
2.16.5 - ABS on the Tractor Oniy or Oriy
on the Trailer
Sectior. 2 — Driving Safeiy
"age 2-34
Commercial Driver's License Manual
Having ABS on only the tractor, only the trailer, or
even on only one axe, still gives you more control
over the vehicle during braking. Brake normaily.
When only the tractor has ABS, you should be able
to maintain steering control, and there is less
chance of jackknifing. But keep your eye on the
trailer and let up on the brakes (i you can safely do
s0) ¡f it begins to swing out.
When only the trailer has ABS, the trailer is less
likely to swing out, but if you lose steering control
or stert 2 tractor jackknife, ‘at up on the brakes (if
you can safely do so) until you regai contro:
2.18.6 — Eraking with ABS
When you drive a vehicle with ABS, you should
brake as you aways have. In other words:
Use only tha braking force necessary to stop safely
and slay in control.
Brake the same way, regardless of whether you
have ABS on the bus, tracior, the trai-er, or both.
As you slow down, monitor your tracior and trailer
and pack off the brakes (if it is safe to do so) to
stay in control.
There is only one exception to this procedure. If
you drive a straight truck or combination with
working ABS on all axles, in an emergency stop,
you can fuily apply the brakes.
2.18.7 — Braking If ABE Is Not Working
Without ABS you still have normal brake functions.
Drive and Drake as you a'ways have.
Vehicles with ABS have yellow malfunction lamps
to teil you if something isn't working.
As a system check on newer vehicles, the
malfunction lamp comes on at start-up for a bulo
check and then goes out quickly. On older
systems, the lamp could stay on until you are
driving over five mph.
If the lamp stays on after the bulb check, or goes
on once you are under way, you may have 1ost
ABS control on one or more whees.
Remember, if your ABS maifunctions, you still
have regular brakes. Drive normally, but go! с
sysiem serviced soon.
2.78.8 -- Lalelv Reminders
ABS won't allow you to drive faster, follow more
closely, or drive less carefully.
ABS won prevent power or furning skids-ABS
should prevent brake-induced skids or jackknifes,
but not those caused oy spinning the drive whee's
or going too fast in a turn.
ABS wont necessarily snorien stopping distance.
ABS wil help maintain vehicle conirol, but not
aways shorten stopping distance.
ABS won't increase or decrease ultimate stopping
power--ABS is an "aad-on’ io your normal brakes,
not a replacement for them.
ABS won't change the way you normally brake.
Under normal brake conditons, vour vehicle wil
stop as :t always stopped. ABS oniy comes into
play when a whee would normally have tocked up
because of over braking.
ABS wont compensate for bad brakes or poor
brake maintenance.
Remember: The best vehicle safety feature is
still a safe driver.
Remember: drive so YOU never need to use
your ABS.
Remember: if you need it, ABS could help to
prevent a serious crash.
2.19 — Skid Control and Recovery
A skid happens wicnever the tires lose their grip
on tne road. This is caused in one of four ways:
Qver-braking. Braking too hard and iocking up the
wheels. Skids also car occur when using the
speed retarder when the road is slippery.
Gver steering. Turning the wheels more sharply
than the vehicle can turn.
Qver-acceleration. Supplying too much power to
the drive whee!s, causing thern to spin.
Driving Too Fast. Most serious skids result from
driving too fasi for road conditions. Drivers who
adjus: their driving to conditions don't over-
accelerate and don't have to over-brake or over-
steer from too much speed.
2.78.7 — Drive-wheel Skids
By far :he most common skid is one in which the
res” wheels wse tracton through excessive
braking or acceleration. Skids caused by
acceleration usually happe: on ice or snow.
Taking your foot off the accelerator can easily stop
them. ( it is very slippery, push the cluich in.
Othe vise, (he angine can keep the «+heeis from.
rolling freely and regaining iraciior.)
Section 2 — Driving S-fe:y
Page 2-23
Commercial Driver's License Manual
Rear wheel braking skids occur when the rear
drive wheels lock. Because locked wheels have
less traction than rolling wheels, the rear wheels
usually slide sideways in an attempt to "catch up”
with the front wheels. in a bus or straight truck, the
vehicle will slide sideways in a “spin out.” With
vehicles towing trailers, a drive-wheel skid can let
the trailer push the towing vehicle sideways,
causing a sudden jackknife. See Figure 2.19.
Figure 2.19
2.19.2 — Correcting a Drive-wheel Braking
Do the following to correct a drive-wheel braking
Stop Braking. This will let the rear wheels roll
again, and keep the rear wheels from sliding.
Countersteer. As a vehicle turns back on course,
it has a tendency to keep on turning. Unless you
turn the steering wheel quickly the other way, you
may find yourself skidding in the opposite direction.
Learning to stay off the brake, turn the steering
wheel quickly, push in the clutch, and countersteer
in a skid takes a lot of practice. The best place to
get this practice is on a large driving range or “skid
2.19.3 — Front-wheel Skids
Driving too fast for conditions causes most front-
wheel skids. Other causes include lack of tread on
the front tires and cargo loaded so not enough
weight is on the front axie. In a front-wheel skid,
the front end tends to go in a straight line
regardless of how much you turn the steering
wheel. On a very slippery surface, you may not be
able to steer around a curve or turn.
When a front-whee! skid occurs, the only way to
stop the skid is to let the vehicle slow down. Stop
turning and/or braking so hard. Slow down as
quickly as possibie without skidding.
—— ii ft 'Eh—N——_—_—_—————__———_—_—$S__—lhhhS——u55S—u1
Subsections 2.17, 2.18, and 2.19
Test Your Knowledge
1. Stopping is not always the safest thing to do
in an emergency. True or False?
2. What are some advantages of going right
instead of left around an obstacle?
3. What is an "escape ramp?”
4. [If a tire blows out, you should put the brakes
on hard to stop quickly. True or False?
5. How do you know if your vehicle has antilock
6. What is the proper braking technique when
driving a vehicle with antifock brakes?
7. How do antilock brakes help you?
These questions may be on the test. If you can't
answer them all, re-read subsections 2.17, 2.18,
and 2.19.
— — —_— x
===== nn ===" —
Section 2 — Driving Safely
Page 2-36
Commercial Driver's License Manual
2.20 — Accident Procedures
When you're in an accident and not seriously hurt,
you reed to ac to prevent further damage or
injury. The basic steps to be taken at any accident
are to:
Protect the area.
Notify authorities.
Cara for the injured.
2.20.7 -- Profect the Area
The first thing to do at an accident scene is to keep
another accident from happening in the same spot.
To protect the accident area:
i your vehicie is involved in the accident, try to get
it to the side of the road. This wii help prevent
another accident and aliow traffic to move.
if you're stopping to hep, park away from the
accident. The area immediately around the
accident will be needed for emergency venicles.
Put on your flashers.
Set out reflective triangles to warn other traffic.
i lake sure other drivers can see them in time to
avoid the accident.
2.20.7 - Hotify Authorities
If you have a cell phone or CB, call for assistance
before you get out or your vehicle. If not, wait until
after the accident scene has been properly
protected, then phone or send someone to phone
the police. Try to determine where you are so you
can give the exact location.
2.20.3 — Care Tor tho Injured
if à qualified person is at the accident and helping
the injured, stay out of the way unless asked to
assist. Otherwise, co the best you can to help any
injured parties. Here are some simple steps to
fol.ow in giving assistance;
Don’t move a severely injured person unless the
danger of fire or passing traffic makes it necessary.
Stop heavy bieeding by applying direct pressure to
the wound,
Keep the injured person warm.
2.21 ~ Fires
Truck fires can cause damage and injury. Learn
the causes of fires and how to prevent tner. Know
what to do to extinguish fires.
2.21.1 —- Causes of Fire
The foliowing are some causes of veticle fires:
After Accidents. Spilled fuel, improper use of flares.
Tires. Under-inflated tires and duals that touch.
Electrical System. Short circuits due to damaged
insulation, locse connections.
Fuel. Driver smoking, improper fueling, loose fuel
Cargo. Flammable cargo, improperly sealed or
loaded cargo, poor ventilation.
2.21.2 — Fire Prevention
Pay attention to te following:
Pre-trip Inspection. Make a comniete inspection of
the electrical, fuel, and exhaust systems, tires, and
cargo. Be sure to check that the fire extinguisher is
En Route Inspection. Check the tires, waeels, and
truck body for signs of heat whenever you stop
during a trip.
Follow Safe Procedures. Follow correct safety
procedures for fusling the vehicle, using brakes,
handling flares, and other activities that can cause
a fire.
Monitoring. Check the instruments and gauges
often for signs of overheating ang use the mirrors
to look for signs of smoks from tires or tre vehicle.
Caution. Use norma! caution in handling anything
2.21.3 - Fire Fighiing
Krowing how to fight fires is important, Drivers who
didnt know what to do have made fires worse.
Ki0w how the fire extinguisher vrorks. Study the
instructions printed on the extinguisher before you
need it. Here are some procedures to fofow in
case of fire.
Pull Off the Road, The first step is to get the
vehicle off thé road and séop. in doing so:
Park in an open area, away from buildings, trees,
brush, other vehicles, or anything that might catcii
Don't puil into à service station!
Notify emergency services of your problem and
your location.
Keep the Fire from: Goreading. Before tying fo
put out the fire, make sure that it doesn't spread
any further.
Section 2 — Driving Safely
Sage 2-37
Commercial Driver's License Manual
With an engine fire, turn off the engine as soon as
vou can. Dont open the hood if you can avoid it.
Shoot foam through louvers, radiator, or from the
vehicie's underside.
For a cargo ‘ire in a van or box trailer, keep the
doors shut, especially 1? your cargo contains
hazardous materals. Opening the van doors will
supply the fire with oxygen and can cause it to
burn very fast.
Extinguish the Fire, Here are some rules to follow
in putting out a fire:
When using ihe extinguisher. stay as far away from
the fire as vossibis.
Aim at the source or base of the fire, not up in the
Use tie Right Fire Extinguishe:
Figures 2.20 and 2.21 detail the type of fire
extinguisher to use by class of fire.
The B:C type fire extinguisher is designed to work
on electrical fires and burning liquids.
The A:B:C type is designed to work on burning
wood, paper, and cloth as wall,
Water can be used on v/ood, paper, or cloth, but
dont use water on an electrical fire (can cause
shock) cr a gasoline fire (it will spread the flames).
A burning lire mus: be cooled. Lots of water may
oe required.
If you're not sure what to use, especially on &
hazardous materials fire, wait for firefighters.
Position yourself upwind. Let the winc carry the
extinguisher to the fire.
Continue until whatever was burning has been
cooled. Absence of smoke or flame does not mean
the fire cannot restart.
Class! ype of Fires
Class | Type
А Wood, Paper, Ordinary Combustibles
Extinguish by Cooiing and Quenching
Using Water or Dry Chemicals
B Gasciinc, Oil, Grease, Other Greasy
| Extinguish by Smothering, Cooling or
| Heat Shielding vsing carbon Dioxide or
Dry Chemicals
C E‘ectrical Equipment Fires
Extinguish with Norconducting Agents
such as Carbon Dioxide or Dry
Chemicals. DO NOT USE WATER.
D Fires in Combustible Metals
Extinguish by Usir.g Specialized
Extinguishing Powders
rigure 2.20
Sectior: 2 — Diving Safeiy
Dry Powder
Figure 2.21
Subsections 2.20 and 2.21
rest Your Knowledge
1. What are some things to do at an accident
scene lo prevent another accident?
2. Name bvo causes of tire fires.
3. What kinds of fires is a B:C extinguisher
not good for?
4, When using your extinguisher, should you
get as close as possible to the fire?
5. Name some causes of vehicle fires.
These questions may be on the test. If you can't
arswer them all, re-read subsections 2.20 and 2.21.
Page 2-38
Commercial Driver's License Manual
2.22 - Alcohol, Other Drugs, and
2.22,1 — Alcohol and Driving
Drinking alcohol and then driving is very dangerous
and a serious probiem. People who drink alcohc!
are involved in taffic accidents resulting in over
20,000 deaths every year. Alcohol impairs muscle
coordination, reaction time, depth nerception, and
night vision, it also affecis the paris of the brain
that control juggment and inhibition. For some
people, one drink is all it takes to show signs of
How Alcohol Works. Alcohol goes directly into
the blood stream and is carried to the brain. After
passing through the brain, a small percentage is
removed in urine, perspiration, and by breathing,
while the rest is carried to the liver. The liver can
only process one-third an ounce of alcohol per
hour, which is considerably less than the alcohol in
a standard drink. This is a fixed rate, so only time,
not black coffee or a cold sho ver, will sober you
up. 'f you have drinks faster than you: body can
get rid of them, you will have more alcohol in your
body, and your driving wili be more affected, The
Blood Alcohol Concentration (BAC) commonly
measures the amount of alcohol in your body. See
Figure 2.22.
Ali of tre following drinks contain the same amount
of alcohol:
À 12-ounce glass of 5% beer.
À 5-ounce giass of 12% wine.
A 1 1/2-0unce shot of 80 proof liquor.
What Determines Blood Alcohol
Concentration? BAC is determined by the amount
of alcohol you drink (more alcohol means higher
BAC), how fast you drink (faster drinking means
higner BAC) and your weight (a smali person
doesn't have to drink as much to reach the same
Alcohol and tiie Brain. Alcohol affects more and
more of the brain as BAC builds up. The first part
of the brain affected controls judgment and self-
control. One of the bad things about this is it can
keep drinkers from knowing they are getting drunk.
And, of course, good judgment and self-control are
absolutely necessary for safe driving.
| OMIDal e Dip TS the alcohol ón gine
hat Aena fuman performance. E doesn't |
make Ey difference whether за? аси: |
cornes from ‘a couple of beers.” or om |
two grasses of wine, or two shots of hand
Biar Aoprogioate Blood Alesha
ol CORTE “|
с TAT ао 1a
=. =i
5 o
5 Body Weight in Pounds =
5 © © о E с D | ©
| ZC
=D =
о | co | co | .00 | .00 | .00 | 20 | 00‘ оо P €
| ‘©
| Е
1 | .с% | .03 1.03 | .02 . ‚02 | 02.02 | 02 Р 3
|| 5
2 {08 { 06 | .05 | .05 ! 04 | 04 | 031 В Е
| 6
3 +4 ; .G& | .08 | .07 | 06 | .06 | .05 | 05 +
4 45 1.12 | .11 1.09 | .08 1.08 | .07 T 06 97
5 19 | .4G | .13 | 12 1.41 | .09 1.09 | .08 €
| 5
6 j.23|.00 161.44 | 13.11 | 10 | 09) 3
| Ca
7 26 | 22 1,19 1.78 1.75 | 43 1.12 1.11 38
8 1 .30 1 .25 | 21 | .19 ! “7 | 15] 14 | 13 5
© } 34 | .28 | 24 | 2° #911 47 15 | 34 6 E
10 ; .38 | 31 | 27 | 23 21 | 19 Ау | 16
| | |
Subtract .01% for each 40 minutes of drinkirg. One !
drink is 1.25 oz. of 80 proof liquor, 12 az. of beer,
or 5 oz. of tabls wine.
Figure 2.22
As BAC continues to build up, muscie control,
vision, and coordination are affected more and
more, Effects on driving riay include:
Straddling lanes.
Quick, jerky starts.
Not signaling, failure to use lights.
Section 2 — Driving Safely
Page 2-35
Commercial Driver's License Manual
Running stop signs and red lights.
Improper passing.
See Figure 2.23.
These effects mean increased chances of a crash
end chances of losing your drivers license.
Accident statistics show that the chance of a crash
is much greater for drivers who have been drinking
than for drivers who have not
| Tacita Of increasing
| Sigue Alegho Content
your blood recorded in milligrams of alcoñol per “00
milliiters of blood. Your BAC depends on the amount
of blood (which increases with weight} and the
amount of alcoho! you consume over time (hc: {asl
you drink). The faster you drink, the higher your
BAC, as the liver can only handie about one drink
per hour- the rest builes up in your biood.
- ах
paca, оон ann —
Blood Alcohol Content is the amount of alcohol in
Effects on Driving
BAC Effects on Body Condition
Mellow feeling, slight eLo
02 body warmth. Less inhibited.
Less alert, less self-
: . focused,
05 Noticeable relaxation. coordination
impairment begins,
Definite impairment in Drunk driving trail,
o impaired
08 coprdination & coordination &
ued ; judament.
Noisy, possible
embarrassing Reduction in
behavio:, mood reaction time.
Impaired balance &
45 movement, clearly
Unable to drive,
Many lose
30 consciousness.
Most lose
40 consciousness, some
50 Bresthing steps,
many díe.
BAC of ,10 means that 1/10 of 7 % (or 1/1000) of
your tola: blood contentis alcoho!.
Figure 2.23
How Aicoho! Affects Driving. All drivers are
affectec by drinking alcohol. Alcoho! affects
judgment, vision, coordination, and reaction time. i
causes serious driving errors, such as:
Increased reaction tme to hazards.
Driving too fast or too slow,
Driving in tha wrong lane.
Running over the curb.
2.22.2 — Other Drugs
Besides alcohol, other legal and illegal drugs are
being used more often. Laws prohibit possession
or use of many drugs while on duty. They prohibit
being under the influence of any “controlled
substance,” amphetamines (including “pep pis,”
“uppers,” and "bennies”), narcotics, or any other
substance, which can make the driver unsafe. This
could include a variety of prescription and over-the-
counter drugs (cold medicines), whicti may makes
the driver drowsy or otherwise affect safe driving
ability. However, possession and use of 2 drug
given to a driver by a doctor is permitted if the
doctor informs the driver that it will not affect safe
driving ability.
Pay attention to warning labels for legitimate drugs
and medicines, and to doctors orders regarding
possiole effects. Stay away from illegal drugs.
con't use any drug that hides fatigue-the only cure
for fatigue is rest. Alcoho: can make the effects of
other drugs much worse. The safesi rule is don’
mix drugs with driving at ail.
Use of drugs can lead to traffic accidents resuiting
fn death, iriury, and property damage.
Furthermore, it can lead to arrest, fines, and ja.
sentences, ¡t can also mean the end of a person's
oriving career.
2.23 ~ Staying Alert and Fit te Drive
Driving a vehicle for long hours is tiring. Even the
best of drivers will become less alert. However,
there are things that good drivers do to help stay
alert and safe.
2.£3,1 — Be Ready to Drive
Get Enough Sleep. Sleep is not like money, You
can't save it up ahead of time and you can’t borrow
t. But, just as with money, you can go into debt
with it. If you don't sieep enough, you “owe” more
sieep to yourself. This debt can only be paid off by
s.eeping. You can't overcome it with willpower, and
it wont go away by itself. The average person
needs seven or eight hours of sleep every 24
hours. Leaving on a long trip when vou're already
tred s dangerous. If усы nave a long tri
scheduled, make sure that you get enough sieen
berore you go.
Section 2 - Driving Safe:y
Page 2-*0
Commercial! Driver's License Manual
Schneduie Trips Safeiy. Try to arrange your
schedule so you are not in "sleep debt” before a
tong trip. Your body gets used to sleeping during
certair: hours, If you are driving during those hours,
you will be less alert. If possible, try to schedule
trips for the hours you are normally awake. Many
heavy inclor vehicle accidents occur between
ridnight and 6 a.m. Tired drivers can easily fall
asleep at these times, especially if they don“
regularly drive at those hours. Trying to push on
and finish à long trip at these times can be very
Exercise Regularly. Resistance to fatigue and
improved seep ae among the benefits of regular
exercise. Try to incorporate exercise into your daily
life, instead of sitting and watching TV in your
sleeper, walk or jog a few laps around the parking
lot. A little bit of daily exercise will give you energy
throughout the day.
Eat Healthy. It is often hard for drivers to find
healthy food. But with a ¡lite extra effort, you can
ea: healthy, even on the road. Try to find
restaurants with healthy, balanced meals. If you
must eat at fast-food restaurants, pick low-fat
items. Another simple way to reduce your caloric
intake is to eliminate fattening snacks. Instead, try
fruit or vegetables,
Avoid Medication. Many medicines can make you
sleepy. “hose that do have a label warning against
operating vehicles or machinery. The mosi
common medicine of this type is an ordinary cold
pill. If you have to drive with a cold, you are better
off suffering from the cold than from the effects of
the medicine.
Visit Your Doctor. Reguiar checkups literally can
be lifesavers. llinesses such as diabetes, heart
disease, and skin and colon cancer can be
detected easily and treated if found in time.
You should consult your physician or a local sleep
disorder center if you suffer from freauent dayiime
sleep.ness, have difficulty sleeping at night, {ake
frequent naps, fal asleep at strange times, snore
loudly, gasp and choke in your sleep, and/or wake
up feeling as though you have not hac enough
2.23.2 — While You Are Driving
Keep Cool. A hot poorly ventilated vehicle can
make you sleepy. Keep the window or vent
crackeu open or use the air conditioner, if you
have one.
Take Breaks. Short breaks can keep you alert. But
the time to take them is before vou feel really
drowsy or tired. Stop often. Walk around and
inspect your vehicle. It may help io do some
physical exercises.
Be sure to take a mid-afternoon break and plan to
sleep between midnight and 6 a.m.
Recognize the Danger Signals of Drowsy
Driving. Sigep is not voluntary. If you're drowsy,
you can fall asleep ang never even know it. If you
are drowsy, you are likely to have "micro sleeps”-
brief naps that last around four or five seconds. At
55 miles an hour, that's more than 100 yards, and
Aenty of time for a crash, Even if you are not
aware of being drowsy, if you have a sleep debt
you are stil at risk, Here are a few ways to tell if
you're about to fall asleep. 'f you experience any of
nese danger signs, take them as a warning that
you could fall asieep without meaning to.
Your eyes close or go out of focus by themselves.
You have trouble keeping your head up.
You can't stop yawning.
You have wandering, disconnected thoughts.
You don't remember driving the last few miles.
You drift between lanes, tailgate, or miss traffic
You keep jerking the truck back into the lane.
You have drifted off the road and narrowly missed
If you have even one of these symptoms, you may
be in canger of faking asleep. Pull off the road ina
safe place and take a nap.
2.23.3 — When You Do Becume Sleepy
When you are sleepy, trying to “push on” is far
more dangerous than most drivers think. it is a
major cause of fatal accidents. Here are some
important rules to follow,
Slop to Sleep. When your body needs sieep,
sleep is the only thing that will work. If you have to
таке а stop anyway, make it whenever you feel
the first signe of sleepiness, even if it is earlier than
you piannea. By getting up a little earlier the next
day, you can keep on schedule without ihe danger
of driving while you are not alert,
Take a Map. IY you can't stop for the night, at least
puli off at & safe place, such as a rest area or truck
stop, and take a nap. A nap as short as a half-hour
will do more to overcome fatigue thar a half-hour
coifee stop.
Section 2 — Drivirc Safely
Page 2-41
Commercial Drive”s License Manual
Avoid Drugs. There are no drugs that can
overcome being tired. While they may keep you
awake for e while, they ont make you alert, And
eventually, you'll be even more tired than if you
hacnt taken them at all. Sleep is the only tung that
can overcome fatigue.
Do Not, Do rot rely on coffee or another source of
caffeine to keep you awake. Do not count on the
radio, an cpen window, or other tricks to keep you
2.23.4 ~ lllness
Once in a while, you may become so iil that you
cannot operate = motor vehicle safely. If this
happens to you, you must not drive. However, in
case of an emergency, you may drive to the
nearest place wnere you can safeiy stop.
2.24 - Hazardous Materials Ru'es For
Ali Commercia! Drivers
All drivers should know something about
hazardous materials. You must be able to
recognize hazardous cargo, and you must know
whether or not you can haul it without having a
hazardous materigls endorsement on your CDL
2.24.1 — Vhat Are Hazardous Materials?
lazarcous materials are products that pose a risk
to health, safety, and property during
transportation. See Figure 2.24.
2.24.2 —~ Wiñy Are There Ruies?
You must folow the many rules about transporting
hazardous materials. The intent of the rules Is to:
Contain the product.
Communicate the rigk.
Ensure safe drivers ard equipment.
To Contain the Product. Many hazardous
products can injure or kill on contact. To protect
drivers and others from contac*, the rules tell
shinpers how to package safely. Similar rules tel
drivers how to load, transport, ano unload bulk
tanks. 1 hese are containment rules.
Hazard Class Dafiutiona
Class | Class Name Example
1 Expiosives Dynamite,
5 Gases Propane, Oxygen,
3 Flammable Gasoline Fuel,
Flammable В
4 Solids | Matches, Fuses
I Ammonium
5 Oxidizers Nitrete, Hydragen
6 Poisons Pesticides,
| ‘( . Uraniur,
7 Radioactive Plutonium
"vrai Hydrochloric Acid,
8 Corrosives Baitery Acid |
9 Hazardous ormatdenyde,
Materials Stl |
ORM-D (Other
Regulated Hair Spray or
None Meterial- Charcoal
Combustible Fuel Oils, Lighter
None Liquics Fluid
Figure 2,24
Te Communicate the Risk. The shipper uses a
shipping paper and diamond shaped hazard abels
to warn dockworkers and drivers of the risk.
After an accident or hazardous material spill or
leak, you may be injured and unabe to
communicate the hazards of the materials you are
transporting. Firefighters and police can prevent or
reduce the amount of damage or injury at the
scene if they know what hazardous materials are
being carried. Your life, and the lives of others,
may depend on quickly 'ocating the hazardous
materials shipping papers. For that reasor, you
must tab shipping papers related to hazardous
materials or keep them on top of other shipping
papers. You must also keep shipping papers:
In a pouch on the driver's door, or
In clear view within reach while driving, or
On the driver's seat when out of the vehicle.
£.24.3 — Lists of ARsguietes! Products
Placards are used to warn others of hazardous
meteriais. Placards are signs put on the outside of
a vehicle tha! icentify the hazard class of the
Section 2 ~ Driving Safely
Page 2-42
Commercial Driver's License Manual
cargo. A placarded vehicle must have at least four
identical placards. They are put on the front, rear,
and both sides. Placards must be readable from all
four directions. They are at least 10 3/4 inches
square, turned upright on a point, in a diamond
shape. Cargo tanks and other bulk packaging
display the identification number of their contents
on placards or orange paneis.
identification Numbers are a four digit code used
by first responders to identify hazardous materials.
An identification number may be used to identify
more than one chemical on shipping papers. The
identification number will be preceded by the
letters “NA” or "UN”. The US DOT Emergency
Response Guidebook (ERG) identifies the
chemicals all identification numbers ara assigned
Not all vehicles carrying hazardous materials need
to have placards. The rules about placards are
given in Section 9 of this manual. You can drive a
vehicle that carries hazardous materials if it does
not require placards. К it requires placards, you
cannot drive it unless your driver ficense has the
hazardous materials endorsement. See Figure
The rules require all drivers of piacarded vehicies
to learn how to safely load and transport
hazardous products. They must have a commercial
driver license with the hazardous materials
endorsement. To get the reguired endorsement,
you must pass a written test on material found in
Section 9 of this manual. A tank endorsement is
required for certain vehicles that transport liquids
or gases. The liquid or gas does not have to be a
hazardous material. A tank endorsement is only
required if your vehicle needs a Class A or B CDL
and your vehicle has a permanently mounted
cargo tank of any capacity, or your vehicle is
carrying a portable tank with a capacity of 1,000
gallons or more.
Drivers who need the hazardous materials
endorsement must learn the placard rules. If you
do not know if your vehicle needs placards, ask
your employer. Never drive a vehicle needing
placards unless you have the hazardous materials
endorsement. To do so is a crime. When stopped,
you will be cited and you will not be allowed to
drive your truck further, K will cost you time and
money, A failure to placard when needed may risk
your life and others if you have an accident.
Emergency help wili not know of your hazardous
Figure 2.25
Hazardous materials drivers must also know which
products they can foad together, and which they
cannot. These rules are also in Section 9. Before
loading a truck with more than one type of product,
you must know if it is safe to load them together. If
vou do not know, ask your employer.
Subsections 2 2.22, 2. 23, and 2.24
Test Your Knowledge
1. Common medicines for colds can make
you sleepy. True or False?
What should you do if you become sleepy
while driving?
Coffee and a little fresh air will help a
drinker sober up. True or False?
What is a hazardous materials placard?
Why are placards used?
What is "sleep debt"?
What are the danger signals of drowsy
NE ее N
These questions may be on the test. If you can't
answer them all, re-read subsections 2.22, 2.23,
and 2.24.
Section 2 — Driving Safely
Page 2-43
Commercial Driver's Licrnse Manual
aly. Ea
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This Section Covers
» Inspecting Carge
« Cargo Weight and Balance
= Securing Carge
« Cargo Needing Special Attention
This section lelis you about nauling cargo safely.
You must undersiand basic cargo safety rulas to
get a CDL.
if you load cargo wrong or de not secure it, it can
be a danger to others and yourself. Loose cargo
that falls off a vehicle can cause traffic problems
and others could be hurt or killed. Loose cargo
could hurt or kil you during a quick stop or crash.
Your veiicle could be damaged by an overload.
Steering could be affected by how a vehicle is
loaded, making it more difficult to control the
Whetner or not you load and secure the cargo
vourse f, you are responsible for:
Inspecting your cargo,
Recognizing overloads and poorly baanced
Knowing your cargo is properly secured and does
not obscure your view ahead or to the sides. *
Knowing your cargo does not restrict your access
to emergency equipment.
if you intend to carry hazardous material that
requires placards on your vehicie, you will also
need to have a hazardous materials endorsement.
Section 8 of this manual has the information you
need to pass the hazardous materials test.
3.1 ~ Inspecting Cargo
As part of your pre-trip inspection, make sure the
truck is not overioadec and the carro is balanced
and properly,
Ate: Starting. Inspect the cargo and its securing
devices again within the first 50 miles after
beginring e tip. Maxe any adjustrents neeced.
Re-check. Re-check the cargo and securing
devices as often 25 necessary during a trip to keep
the lozd secure, You nead lo inspect again:
Afte: you have driven for 3 hours or 150 miles.
After every break you take during driving.
Federal, state, and local regulations tor commercial
vehicle weight, securing cargo, covering loads, and
where you car Grive large vehicles vary from place
to place. Know the rules where you will be driving.
2.2 - Weight and Balance
You are responsible for not being overioaded. The
following are some definitions of weight you should
3.2.1 — Definitions You Should Know
Gross Vehicie Weight (GVW). The total weight of
a sing'e vehicle pius its load,
Gross Combination Weight (GCW) The loial
weight of a powered unit, plus trailer(s), plus the
Gross Vehicle Weight Rating (GVWR). The
maximum GVW specified by the manufacturer for a
single vehicle plus its load.
Gross Combination Weight Rating (GCWR).
The maximum GCW specified by the manufacturer
for a specific combination of vehicles pius its load.
Axle Weight. The weight transmitted to the ground
hy one ax'e or one sei of ax'es.
Tire Load. The maximum safe weight a tire can
carry at a specified pressure. This rating is stated
on the side of each tire,
Suspension Systems. Suspension systems have
a manufacturers weignt capacity rating.
Coupiing Device Capacity. devices are
rated for the maximum weight they can pull and/or
3.2.2 — Legal Weight Limits
You must keep weights within legal limits. States
have maximums for GVWs, GCWs, and axle
weignts. Orien. maximum axle weights are set by a
bridge formula. À bridge formula permits ¡ess
maximum axle weight for axles that are closer
together. This is io prevent overloading bridges
and roadways.
Section 3 - Transportine Carco Safe y
Page 3-1
Commercial Driver's License Manual
Overloading can have bad effects on steering,
braking, and speed control. Overloaded trucks
have to go very slowly on upgrades. Worse, they
may gain too much speed on downgrades.
Stopping distance increases. Brakes can fail when
forced to wark too hard.
During bad weather or in mountains, it may not be
safe to operate at legal maximum weights. Take
this into account before driving.
3.2.3 — Don't Be Top-heavy
The height of the vehicle's center of gravity is very
important for safe handling. A high center of gravity
(cargo piled up high or heavy cargo on top) means
you are more likely to tip over, It is most dangerous
in curves, or if you have to swerve to avoid a
hazard. it is very important to distribute the cargo
so it is as low as possible. Put the heaviest parts of
the cargo under the lightest parts.
3.2.4 — Balance the Weight
Poor weight balance can make vehicle handling
unsafe. Too much weight on the steering axle can
cause hard steering. It can damage the steering
axle and tires. Under-loaded front axles (caused by
shifting weight too far to the rear) can make the
steering axle weight too light to steer safely. Too
little weight on the driving axles can cause poor
traction. The drive wheels may spin easily. During
bad weather, the truck may not be able to keep
going. Weight that is loaded so there is a high
center of gravity causes greater chance of rollover.
On flat bed vehicles, there is also a greater chance
that the load will shift to the side or fall off. See
Figure 3.1.
3.3 — Securing Cargo
3.3.1 — Blocking and Bracing
Blocking is used in the front, back, and/or sides of
a piece of cargo to keep it from sliding. Blocking is
shaped to fit snugly against cargo. It is secured to
the cargo deck to prevent cargo movement.
Bracing is also used to prevent movement of
cargo. Bracing goes from the upper part of the
cargo to the floor and/or walls of the cargo
Wrong Right |
Lo E
Wrong Right
Figure 3.1
3.3.2 — Cargo Tiedown
On flatbed trailers or trailers without sides, cargo
must be secured to keep it from shifting or falling
off. In closed vans, tiedowns can also be important
to prevent cargo shifting that may affect the
handling of the vehicle. Tiedowns must be of the
proper type and proper strength. Federal
regulations require the aggregate working load limit
of any securement system used to secure an
article or group of articles against movement must
be at least one-half times the weight of the article
or group of articies. Proper tiedown equipment
must be used, including ropes, straps, chains, and
tensioning devices (winches, ratchets, clinching
components). Tiedowns must be attached to the
vehicle correctiy (hooks, bolts, rails, rings). See
figure 3.2.
Cargo should have at least one fie-clown for each 10 fest of cargo,
Make sure you have enough lie-downs to meet this need, No matter
how small the cago is, there should be at least two tie-downs holding it,
В by:
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Figure 3.2
Section 3 - Transporting Cargo Safely
Page 3-2
Commercial Driver's License Manual
Cargo shouid have at least one tiedown for each
ten feet of cargo. Make sure you have enough
tedowns to meet this need. No matter how small
the cargo, it should have at ieast two tiedowns.
There are special requirements for securing
various heavy pieces of metal. Find out what they
are if you are to carry such :0ads.
3.5.3 — Header Boards
Front-end header boards (“headache racks”)
protect you from your cargo in case of a crash or
emergency stop. Make sure the front-end structure
is in good condition. The front-end structure should
block the forward movement of any cargo you
3.3.4 — Covering Cargo
“here are two basic reasons for covering cargo:
To protect people from spilled cargo.
To protect the cargo from weather.
Spill protection is a safety requirement in many
states. Be familiar with the laws in the states you
drive in.
You should ¡vox at your cargo covers in the mirrors
from time to time while ariving. À flapping cover
can tear loose, uncovering the cargo, and poss.bly
biock your view or somecne else's.
3.3.8 -- Sealed and Containerized Loads
Containerized loads generally are used when
freight is carried part way by rai or ship. Delivery
by truck occurs at the beginning and/or end of the
journey. Some containers have their own tiedown
devices or locks that attach directly to a special
frame. Others have to be loaded onto flat bed
trailers. They must be properly secured just like
any other cargo.
You cannot inspect sealed ivads, but you should
check that you don't exceed gross weight and axle
weight limits.
3.4 - Cargo Needing Special Attention
3.4.7 — Lry Bulk
yy bulk tanks require special care because they
have a high center of gravity, ard the load can
shift. Be extremely cautious (siov. and careful)
going around curves and making sharp turns.
3.4.2 — Hanging Meat
Hanging meat (suspended beef, pork, lamb) in a
refrigerated wuck can be a very unsiable loac with
a high center of gravity. Particular caution is
needed on sharp curves such as off ramos and on
ramps. Go siowiy.
3.£.3 — Livestoci
Livestock can move around in a trahei, causing
unsafe handling. With ‘ess than a full load, use
false bulkheads to keep livestock punched
together. £ven when bunched, special core is
necessary because livestock can lean on curves.
This shifts the center of gravity and maies rollover
more likely.
3.4.4 -- Oversizec ji oads
Over-length, over-width, and/or overweight loads
recuire special transit permits. Driving is usually
imied to certain mes, Special equipment may be
necessary such as wide oad” signs, flashing
fights, flags, etc. Such loads may require a police
escort or pilot vehicles bearing warning signs
and/or flashing lights. These special loads require
special drivirg care.
Section 3
Test Your Anowiedae
1. What four things related to cargo are
drivers resnonsible for?
2. How often must you stop while on the road
to check your cargo?
3. How is Gross Combination Weight Rating
different from Gross Combination Weight?
4, Name two situations where legal maximum
weights may not be safe,
5. What can happen if you don’t have enough
weight on the front axle?
6. What is the minimum number of tiedowns
tor any flat bed load?
7. What is the minimum number of tiedowns
for a 20-foot load?
8. Name the two nasic reasons for covering
cargo on an open bed.
9. What mus! you check before transporting a
sea:ed load?
These questions may be on your test. If you cant
answer them ail, re-read Section 3.
Sectior 3 - Trensno-ting Cargo Safely
Page 3-3
Cammercizf Driver's License Mantua!
Section 4
ef ta A
EP ud Val Pc 1 Vd PR
This Section Covers
а VYehicie inspection
« Loading
s On the Koac
v After-trie Vehicle Inscection
+ Prohibited Practices
Use of Brake-door Interiocks
Bus drivers must have a commercial driver license
if they drive a vehicle designed to seat more than
16 or more persons, including the driver.
Bus drivers must have a passenger endorsement
on their commercial driver license. To gel the
endorsement you must pass a knowledge test on
Sections 2 and 4 of this manual. (if your bus has
air brakes, you must also pass a knowiedge test on
Section 5,) You must also pass the skills tests
required for the class of vehicle you drive.
4.1 -- Vehicle Inspection
Sefore driving your bus, you must be sure it is
safe. You musi review the inspection report made
by the previous driver. Only if defecis reported
earlier have becn certified as repaired or not
needed to be repaired, should you sign the
previous driver's report. This is your certification
that the defects reported earlier have been fixed.
4.1.1 - Vehicle Sysiems
Make sure these things are in good working order
before driving:
Service brakes, including air hose couplings {if
your bus has a trailer or semitraller).
Parking brake.
Steering mechanism.
Lights and reflectors.
Tres (fro wheels must not have recapped or
regroovea tires).
Windshield wiper or wipers.
Rear-vision mirror or mirrors.
Coupling devices (if present).
Wheels and rims.
Emergency equipment.
5.1.2 — Access Doors and Panels
As you check the outside of the bus, close any
open emergency exits. Also, close any oper
access panels (for baggage, restroom service,
engine, ec.) before driving.
EZ 1.3 - Bus Interror
Peopie sometimes Gamage unattended buses,
Always check the interior of the bus before driving
to ensure rider safety, Aisles and stairwells shouid
aways be clear. The following parts of your bus
must be in safe working condition:
Each handhold and railing.
Flooi covering.
Signaling devices, including the restroom
emergency buzzer, if {ne bus has a restroom.
Emergency exit hancles,
The seats must be safe Tor riders. All seats musi
be securely fastened to the bus.
Never drive ‘vith an open emergency exit door or
window. The ‘Lmergency Exit" sign on ar
emergency door must be clearly visible. If there is
a red emergency door light, it must work. Turn it on
at night or any other time you use your outside
41,4 — Rooÿï Hatches
You may lock some emergency roof hatches in a
partly open position for fresh air. Do not leave them
open as a regular practice. Keep ir mind the bus's
higher clearance wiile driving with them open.
Maxe sure your bus has the fire extirguisher and
emergency roflectors required by law. The bus
must also have spare electrica' fuses, urless
equipped with circuit breakers.
4.1.5 — Lise Your Seatbeit!
The driver's seat should have a seat belt. Always
vse it for safety.
4.2 — Loadirg anc Trip Start
Do not allow riders to leave carry-on baggage in €
doon“ay or aisle. There should be nothing in the
aisie ¡hat might trip o:her riders. Secure baggage
and freight in ways that avoid damage ard:
Sectior 4 - Transponing Passengers Safely
Pzge 4-1
Commercial Driver's License Manual
Allow the driver to move freely and easily.
Allow ricers to exit bv ary window or door in an
Protect riders from injury if carry-ons fall or shift.
£,2.1 ~ Hazardous Materials
Watch for cargo or baggage containing hazardous
materials. Most hazardous materials cannot be
carried on a ous.
The Federal Hazardous Materials Table shows
which materiais aie hazardous. They pose a risk to
health, safety, and property during transportation.
The rules require shippers to mark containers of
Fazardous material with the material's name,
identification number, and hazard label. There are
nine different four-inch, diamond-shaped hazard
labels. See Figure 4.1. Watch for the diamond-
shaped labels. Jo not transport any hazardous
material uniess you are sure the rules allow it.
; Hazard Class Definitions
Class | Class Name : Example
| | Ammunition,
1 Exp.osives Dynamite,
2 Gases Propane, Oxygen,
Gasoline Fuel,
3 _ Flammable Acetone
4 Solids Matches, Fuses
5 Oxidizers Nitrate, Hydrogen
5 Poisons hestoices,
7 ] Radioactive Plutonium
. Hydrochloric Acid,
8 Corrosives Battery Acid
9 Hazardous norme Cehyde,
ORM-D (Other
| Regulatec Hair Spray or
None Material- Charcoal
None Combustible Fuel Qils, Lighter
Licuids Fluid
Figure 4.1
4.2.2 — Forbidden Hazardous Materials
Buses may carry smali-arms ammunition lebeled
ORN-D, emergency hospital supplies, ang drugs.
You can carry small amounts of some other
hazardous materials if the shipper cannot send
then any other way. Buses must never carry:
Division 2.3 poison gas, liquid Class 6 poison, tear
gas, irritating material.
More than 100 pounds of solid Class 6 poisons.
Explosives in the space occupied by people,
excep: small arms ammunition.
Labeled radivective materias in the space
occupied by people.
More than 500 pounds total of allowed hazardous
materials, and no more than 100 pounds of any
one class,
Riders sometimes board a bus with an unlabeled
hazardous material. Do not allow riders to carry on
common hazards such as car batteries or gasoline.
4.2.3 Standez Line
No rider may stand forward of the rear of the
drivers ceat. Buses designed to allow standing
must have a two-inch line on the floor or some
other means of showing riders where they cannot
stand. This is called the stancee line. Al standing
riders must stay behind it.
4.2.4 — At Your Destination
When arriving at the destination or intermediate
stops announce:
The location.
Reason for stopping.
Next cepaærture time.
Bus number.
Remind riders to take carry-ons with them if {hey
get off the bus. If the aisle is on a lower level then
the seats, remind riders of the step-down. It is best
to tell them before coming to a compleie stop.
Charter bus drivers should not allow riders on the
bus until departure time. This wiii nelp prevent theft
or vandalisrit of the bus.
Section 4 - “rensporiing “assergers Safely
Расе 4-2
Commercial Driver's License Мапиа!
4.3 — On the Road
4.3.1 -- Passenger Supervision
Meny cherter and intercity carriers have passenger
comfort and safety rules. Mention ruies about
smoking, drinking, o° use of radio and tape nlayers
at the start of the trip. Explaining the rules at the
start will help to avoid trouble later on.
While driving, scan the interior of your bus as weil
as the road zhead, to the sides, and to the rear.
You may have 0 remind riders about rules, or to
keep arms and heads inside the bus.
6.3.2 — Al Stops
Rideis can stumble when getting on or off, and
when tic bus starts or stops. Caution riders to
watch their step when leaving the bus. Wait for
‘hem to sit down or brace themselves before
starting. Starting and stopoing should be as
smooth as possible to avoid rider injury.
Occasionaly, you may have a drunk or disruptive
rider, You must ensure this nder's safety as wel as
that of others. Don't discharge such riders where it
would be unsafe ior them. It may be safer at the
next scheduled stop or a well-lighted area where
there are other people. Many carriers have
guidelines for handling cisruptive riders.
£.3.3 — Common Accicents
The Most Common Bus Accidents. Bus
accidents ofien happen at intersections. Use
caution, even if a signal or stop sign controls other
traffic. School and mass transit buses sometimes
scrape off mirrors or hit passing vehicles when
puling out from a bus stop. Remember the
ciearance your bus needs, and watch for poles and
tree limbs at stops. Know the size of the gap your
ous needs to acceerate and merge with traffic.
Wait for the gap to open before leaving the stop.
Never assume other drivers vill brake to give you
room when you signal or start to pull out.
4.3.4 — Epeed on Curves
Crashes on curves that kili people and destroy
buses result from excessive speed, often when
rain or snow has made the road slippery. very
banked curve has a за’е "design speed.” In good
weather, the posted speed is safe for cars but it
may be too righ for many ouses. With good
traction, the bus may roll over; with poor traction, it
might slide of the curve. Reduce speed for curves!
If your bus leans toward the outside on a barked
curve, you are driving too fast.
4.3.5 — Railroad-highway Crossings Siops
Stop at RR Crossings:
Stop your vus betveen 15 and 50 feel before
railroad crossings.
Lister: anc lock in both directions for trains. You
should open your forward door if it improves your
ability to see or hear an aoproaching train.
Before crossing after a train has passed, meke
sure there isnt another train coming in the other
direction on other Tracks,
of your bus has a menual transmission, never
change gears while crossing tha tracks.
You do not have to stop, bul must slow down and
carefuily check for other vehicies:
r Al streetcar crossings.
» Where a policeman or flagman is directing
~ Hf a traffic signal is green.
» At crossings marked as “exempt or
4.3,6 — Dravoridges
Stop at Drawbriuges, Stop at drawbridges that do
not have a signal light or traffic control attendant.
Stop at least 50 feet before the draw of the oridge.
Look to make sure the draw is completely ciosed
before crossing. You da not need to stop, but must
slow down and make sure it's safe, when:
There is a traftic light showing green.
The bridge has an attendant or traffic officer who
controls traffic whenever the bridge opens.
4.4 — Aîter-tris Vehicle Inspection
inspect your bus at the end of each shift. if you
work for an interstate carrier, you must complete a
writen inspection report for @ach bus driven. The
report must specify each bus end ist any defect
that would affect safety or result in 2 breakdown. If
there are no defects, the report should say so.
Riders sometimes damage safety-related Darts
such as hancholds, seats, emergency exits, and
windows. If you report this damage at the end of a
shift, mechanics can make repairs before the bus
goes out again. Mass transit drivers should also
make sure passenger signaling devices and drake-
door interiocks woik properly.
Section 4 - Transporting Passangers Safely
Page 1-3
Commercial Driver's License Manual
4.5 — “rohibitad Practices
Avoid fueling your bus vith riders on board unless
absoiutely necessary. Never refuel in a closed
building with riders on board.
Dont talk with riders, or engage in any other
distracting activity, while driving.
Do not iow or push a disabled bus with riders
aboard the vehicle, unless getting off would be
unsafe. Only tow or push the bus 10 the nearest
safe spot to discharge passengers. Follow your
employer's çuicdelines on {owing or pushing
disabled buses.
4.6 -- Use of Brake-door Intericcks
Urban mass transit coaches may have a brake and
accelerator inieriock system. The interlock applies
the brakes and holds the throttle in idle position
when the rear door is open. The interlock releases
when you close the rear door. Do not use this
safety feature in place of the parking brake,
Seciion à
Test Your Knowledge
1 Name some things to check in the interior
of a bus during a pre-trip inspection.
2. What are some hazardous materials you
can transport by bus?
3. What are some hazardous materials you
cant transport by bus?
4. What is à standee line?
5. Does it matter where you make a
disruptive passengei get off the bus?
6. How far from a railroad crossing should
vou stop?
7. Wien must you stop before crossing a
8. Describe from memory the “prohibited
practices” listed in the manual.
9. The rear door of a transit bus has to be
open to put on the parking brake. True or
These questions may be on your test. IF you can't
answer them all, re-read Section 4.
Да Дес ши ша)
ocfion € - Transporting Passengers Safely
Page 4-4
Commercial Driver's License Manual
Section 5
This Section Covers
a Air Brake System Parts
+ Dual Air Brake Systems
s Inspecting Air Brakes
e Using Air Brakes
This section tells you about air brakes. If you want
to drive a truck or bus with air brakes, or pull a
trailer with air brakes, you need to read this
section. If you want to pull a trailer with air brakes,
you also need to read Section 6, Combination
Vehicles. An air brake endorsement is only
required if your vehicle needs а CDL.
Air brakes use compressed air to make the brakes
work. Air brakes are a good and safe way of
stopping large and heavy vehicles, but the brakes
must be well maintained and used properly.
Air brakes are really three different braking
systems: service brake, parking brake, and
emergency brake.
The service brake system applies and releases the
brakes when you use the brake pedal during
normal driving.
The parking brake system applies and releases the
parking brakes when you use the parking brake
The emergency brake system uses parts of the
service and parking brake systems to stop the
vehicle in a brake system failure,
The parts of these systems are discussed in
greater detail below,
5.1 — The Parts of an Air Brake System
There are many parts to an air brake system. You
should know about the parts discussed here.
5.1.1 - Air Compressor
The air compressor pumps air into the air storage
tanks (reservoirs). The air compressor is
connected to the engine through gears or a v-belt.
The compressor may be air cooled or may be
cooled by the engine cooling system. It may have
its own oil supply or be lubricated by engine oil. H
the compressor has its own oil supply, check the
oil level before driving.
5.1.2 — Air Compressor Governor
The governor contrais when the air compressor will
pump air into the air storage tanks. When air tank
pressure rises to the “cut-out” level (around 125
pounds per-square-inch or “psi’), the governor
stops the compressor from pumping air. When the
tank pressure falls to the “cut-in” pressure (around
100 psi), the governor allows the compressor to
start pumping again.
5.1.3 — Air Storage Tanks
Air storage tanks are used to hold compressed air.
The number and size of air tanks varies among
vehicles. The tanks will hold enough air to allow
the brakes to be used several times, even if the
compressor stops working.
5.1.4 - Air Tank Drains
Compressed air usually has some water and some
compressar ofl in it, which is bad for the air brake
system. For example, the water can freeze in cold
weather and cause brake failure. The water and oil
tend to collect in the bottom of the air tank. Be sure
that you drain the air tanks completely. Each air
tank is equipped with a drain valve in the bottom.
There are two types:
Manually operated by tuming a quarter turn or by
pulling a cable. You must drain the tanks yourself
at the end of each day of driving. See Figure 5.1.
Automatic-the water and oil are automatically
expelled. These tanks may be equipped for
manual draining as well.
Automatic air tanks are available with electric
heating devices. These help prevent freezing of
the automatic drain in cold weather.
C= р
Manual Draining Valve
Figure 5.1
Section 5 — Air Brakes
Page 5-1
Commercial Driver's License Manual
5.1.5 — Alcohol Evaporator
Some air brake systems have an alcohol
evaporator to put alcohol into the air system. This
helps to reduce the risk of ice in air brake valves
and other parts during cold weather. Ice Inside the
system can make the brakes stop working.
Check the alcohol container and fill up as
necessary, every day during cold weather. Daily air
tank drainage is still needed to get rid of water and
cil. (Unless the system has automatic drain
5.1.6 — Safety Valve
A safety relief valve is installed in the first tank the
air compressor pumps air to. The safety valve
protects the tank and the rest of the system from
too much pressure. The valve is usually set to
open at 150 psi. If the safety valve releases air,
something is wrong. Have the fault fixed by a
5.1.7 - The Brake Pedal
You put on the brakes by pushing down the brake
pedal. (It is also called the foot valve or treadie
valve.) Pushing the pedal down harder applies
more air pressure. Letting up on the brake pedal
reduces the air pressure and releases the brakes.
Releasing the brakes lets some compressed air go
out of the system, so the air pressure in the tanks
is reduced. It must be made up by the air
compressor. Pressing and releasing the pedal
unnecessarily can let air out faster than the
compressor can replace it. If the pressure gets too
low, the brakes wont work.
5.1.8 —- Foundation Brakes
Foundation brakes are used at each wheel. The
most common type is the s-cam drum brake. The
parts of the brake are discussed below.
Brake Drums, Shoes, and Linings. Brake drums
are located on each end of the vehicle's axies. The
wheels are bolted to the drums. The braking
mechanism is inside the drum. To stop, the brake
shoes and linings are pushed against the inside of
the drum. This causes friction, which slows the
vehicle (and creates heat). The heat a drum can
take without damage depends on how hard and
how long the brakes are used. Too much heat can
make the brakes stop working.
S-cam Brakes. When you push the brake pedal,
air is let into each brake chamber. Air pressure
pushes the rod out, moving the slack adjuster, thus
twisting the brake camshaft. This turns the s-cam
(so called because it is shaped like the letter “S").
The s-cam forces the brake shoes away from one
another and presses them against the inside of the
brake drum. When you release the brake pedal,
the s-cam rotates back and a spring pulls the brake
shoes away from the drum, letting the wheels roll
freely again. See Figure 5.2.
Brake chamber
Brake drum |
Slack adjuster
Adjusting nut
Cam roller
>» ~ Brake
Brake shoe lining
Figure 5.2
Wedge Brakes. In this type of brake, the brake
chamber push rod pushes a wedge directly
between the ends of two brake shoes. This shoves
them apart and against the inside of the brake
drum. Wedge brakes may have a single brake
chamber, or two brake chambers, pushing wedges
in at both ends of the brake shoes. Wedge type
brakes may be self-adjusting or may require
manual adjustment.
Disc Brakes. In air-operated disc brakes, air
pressure acts on a brake chamber and slack
adjuster, like s-cam brakes. But instead of the s-
cam, a “power screw’ is used. The pressure of the
brake chamber on the slack adjuster turns the
power screw. The power screw clamps the disc or
rotor between the brake lining pads of a caliper,
similar to à large c-clamp.
Wedge brakes and disc brakes are less common
than s-cam brakes.
5.1.9 - Supply Pressure Gauges
All vehicles with air brakes have a pressure gauge
connected to the air tank. If the vehicle has a dual
air brake system, there will be a gauge for each
half of the system. (Or a single gauge with two
Section 5 — Air Brakes
Page 5-2
Commercial! Driver's License Manual
needles.) Dual systems will be discussed later.
These gauges tell you ho у much pressure is in the
air tanks.
£.1.10 —~ Application Pressure Gauge
This gauge shows how much air pressure you are
applying io the brakes. (This gauge is not on all
vehicles.) Increasing application pressure fo hold
the same speed means the brakes are fading. You
should slow down and use a lower gear. The need
for increased pressure can also be caused by
brakes out of adjustment, air ¡eeks, or mechanical
3.1.17 ~ Low Air Fressure Warning
À low eir pressure warning signal is required on
vehicies with air brakes. A warning signal you can
see must come on before the air pressure in the
tanks falls below 60 psi. (Or one half the
compressor governor cutout pressure on older
vehicles.) The warning is usually a red light. A
buzzer may also come on.
Another type of warning is the "wig wag.” This
device drops a mechanical arm into your view
when the pressure in the system drops below 60
psi. An automatic wig wag wil rise out of your view
when the pressure in the sysiem goes above 60
psi. The manual reset type must be placed in tre
“out of view” position manually. it will not stay in
pace until the pressure in the system is above 60
On large buses it is common for the low pressure
warning devices to signal al 80-85 psi.
5.1.12 — Stop Light Switch
Drivers behind you must be warned when you put
your brakes on. Tie air brake system does this
with an electric switch that works by air pressure.
The switch turns on the brake lights when you pt
on the air brakes.
5.1.73 - Front Brake Limiting Valve
Some older vehicles (made before 1975) have a
front brake limiting valve and a control in the cab.
The contro! is usually marked “normal” and
“slippery.” When you put the control in the
“s'ipperv position. the [limiting valve cuts the
“normal” air pressure to the front brakes by hall.
Limiting valves were used to reduce the chance of
the front wheels skidding on slippery surfaces.
However, they actually “ecuce the siopping power
of the vehicle. Front wheel braking is good under
Secilon 5 — A: drakes
all conditions. Tests have shown front wheel skids
from braking are not likely even on ice. "lake sure
the contra! is in the "norma! position to have
normai stopping power,
Many vehicles have aulomatic front wheel limiting
velves, They reduce the air to the front brakes
except when the brakes are put on very hard (60
psi or more appication pressure). These vaives
cannot be controlled by the driver,
5.1.74 — Spring Brakes
Alt trucks, truck tractors, and buses must be
equipped wilt emergency brakes and parking
brakes. They must be held on by mechanical forces
(because air pressure can eventually leek away).
Spring brakes are usually used to meet these
needs. Wnen driving, powerful springs are held
back by air pressure. if the air pressure is
removed, the springs out on the brakes. A parking
brake control in the cab allows the driver to let the
air out of the spring brakes. This lets the springs
put the brakes on, A leak in the air brake system,
which causes all the air to be lost, will also cause
the springs to nut on the brakes.
Tractor and straight truck spring brakes will come
fully on when air pressure drops to a range of 20 to
<5 psi (typically 20 to 30 asi). Do not wait for the
brakes to come on automatically. When the low air
pressure warning light and buzzer first come cn,
bring the vehicle to à safe stop right away, while
you can still control the brakes.
The braking power of spring brakes depends on
the brakes being in adjustment. If the brakes are
not adjusted nroperly, neither the regular brakes
nor the emergency/parkirg brakes will work right.
5.1.15 — Parking 3rake Controls
n newer vehicles with air brakes, you put on ihe
parking orakes using a diamond-shaped, yellow,
push-pull control knob. You pull the knob out to put
the parking brakes (spring brakes) on, and push it
in to release them. On older vehicles, the parking
brakes may be controlled by a lever. Use the
parking brakes whenever you park.
Caution, Never push the vrake pecal down when
the spring urekes are on. If you do, the brakes
cout: be damaged vv the combined forces of the
springs and the air pressure. Many brake systems
are cesigned so this wii not heppen. But not ail
systems are set up thai way, and those that ar:
may not aways wok. It is much better to develop
Page 5-3
Commercial Driver's License Manual
the habit of not pushing the brake pedal down
when the spring brakes are on.
Modulating Control Valves. in some vehicles a
control handle on the dash board may be used to
apply the spring brakes gradually. This is called a
modulating valve, it is spring-loaded so you have a
feel for the braking action. The more you move the
control =e he harder the spring brakes come
on. They work this way so you can contro! the
spring brakes if the service brakes fai. When
parking a vehicle with a modulating control valve,
move the lever as far as It will go and hold it in
place with the locking device.
Dual Parking Control Valves. When main air
pressure is lost, the spring brakes come on. Some
vehicles, such as buses, have a separate air tank
which can be used to release the spring brakes.
This is 50 you can move the vehicle in an
emergency. One of the valves is a push-pull type
and is used to put on the spring brakes for parking.
The other valve is spring loaded in the "out
position. When you push the control in, air from the
separate air tank releases the spring brakes so you
can move. When you release the button, the spring
brakes come on again. There is only enough air in
the separate tank to do this a few times. Therefore,
plan carefully when moving. Otherwise, you may
be stopped in a dangerous location when the
separate air supply runs out. See Figure 5.3.
5.1.16 — Antilock Braking Systems (ABS)
Truck tractors with air brakes built on or after
March 1, 1997, and other air brakes vehicles,
(trucks, buses, trailers, and converter dollies) built
on or after March 1, 1998, are required to be
equipped with antilock brakes. Many commercial
vehicles built before these dates have been
voluntarily equipped with ABS. Check the
certification label for the date of manufacture to
determine if your vehicle is equipped with ABS,
ABS is a computerized system that keeps your
wheels from locking up during hard brake
Vehicles with ABS have yellow malfunction lamps
to tell you if something isn’t working.
Tractors, trucks, and buses will have yellow ABS
malfunction lamps on the instrument panel.
Trailers will have yellow ABS malfunction lamps on
the left side, either on the front or rear corner.
Dollies manufactured on or after March 1, 1998 are
required to have a lamp on the left side.
Tractor protection valve
» Provides air supply
» Closes automatically if air supply drops
when driving
The parking brakes, when applied, close the
tractor protection valve and set the spring
brakes at the same time,
Figure 5.3
On newer vehicles, the malfunction lamp comes on
at start-up for a bulb check, and then goes out
quickly. On older systems, the lamp could stay on
until you are driving over five mph.
If the lamp stays on after the bulb check, or goes
on once you are under way, you may have lost
ABS control at one or more wheels,
in the case of towed units manufactured before it
was required by the Department of Transportation,
it may be difficult to tell if the unit is equipped with
ABS. Look under the vehicle for the electronic
control unit (ECU) and wheel speed sensor wires
coming from the back of the brakes.
ABS is an addition to your normal brakes. It does
not decrease or increase your normal braking
capability. ABS oniy activates when wheels are
about to lock up.
ABS does not necessarily shorten your stopping
distance, but it does help you keep the vehicle
under control during hard braking.
Section 5 — Air Brakes
Page 5-4
Commercial Driver's License Manual
Ha nd valve
Pressure Gauge
i Foot Valve 1
Norm mm] A
Compresso A | [- i
One-Way ||
[cneck Valve !
1 aa N
Low Pressure
warning Buzze
and Switch
Safety Valve
Tractor Parking =
Brake Valve (Blue) Emergency Valve \ /
Spring Brake Va
es Highway Valve
Ë ; i Parking B rake
Parking Maxi-Brake Tracia Protection
4 Reservoir
B rake Valve (Yellow) |
Glad nas
Relay Valve
Figure 5.4
Subsection 5.1
Test Your Knowiedge
1. Why must air tanks be drained?
2. What is a supply pressure gauge used for?
3. All vehicles with air brakes must have a
low air pressure warning signal. True or
4, What are spring brakes?
5. Front wheel brakes are good under all
conditions. True or False?
6. How do you know i your vehicle is
equipped with antilock brakes?
These questions may be on your test. if you can't
answer them all, re-read subsection 5.1.
5.2 — Dual Air Brake
Most heavy-duty vehicles use dual air brake
systems for safety. A dual alr brake system has
two separate air brake systems, which use a single
set of brake controls. Each system has its own air
tanks, hoses, lines, etc. One system typically
operates the regular brakes on the rear axe or
axles. The other system operates the regular
brakes on the front axle (and possibly one rear
axle). Both systems supply air to the trailer (if there
is one). The first system is called the “primary”
system. The other is called the “secondary”
system. See Figure 5.4.
Before driving a vehicle with a dual air system,
aliow time for the air compressor to build up a
minimum of 100 psi pressure in both the primary
and secondary systems. Watch the primary and
secondary air pressure gauges {or needles, if the
system has two needles in one gauge). Pay
attention to the low air pressure warning light and
buzzer. The warning light and buzzer should shut
off when air pressure in both systems rises to a
value set by the manufacturer. This value must be
greater than 60 psi.
The warning light and buzzer should come on
before the air pressure drops below 60 psi in either
system. If this happens while driving, you should
stop right away and safely park the vehicle. if one
air system is very low on pressure, either the front
or the rear brakes will not be operating fully. This
means it will take you longer to stop. Bring the
vehicle to a safe stop, and have the air brakes
system fixed.
Section 5 — Air Brakes
Page 5-5
Commercial Drivers License Manua!
5,3 — Inzpeciing Air Brake Systems
You should use tne basic seven-step inspection
procedure described in Section 2 to inspect your
vehicle. There are more things to inspect on a
vehicie with air brakes than one without them.
Tnese things are discussed below, in the order
trey “it into the seven step methad.
5.3.7 — During Step + Engine Compartmar:t
Check Air Compressor Drive Belt (if compressor is
velt-driven). HF the air compressor is belt-oriven,
check the condition and tightness of the belt. №
should be in good condition.
5.3.2 — During Stez 5 V/aikaround
Check Slack Adjusters on S-cam Brakes. Park on
evel ground and chock the wheels to prevent the
vehicle from moving. Release the parking brakes
SO you can move the slack adjusters. Jse gloves
and pull hard on each slack adjuster that you can
reach. if a slack adjuster moves more than about
one inch where the push rod attaches to it, it
probably needs adjustment. Adjust it or have it
adjusted, Vehicles with toc much brake slack can
be very hard to stop. Out-of-adjustment 2rakes are
the most common problem found In roadside
inspections. Be safe. Check the slack adjusters.
All vehicles built since 1994 have automatic slack
adjustors, Even though automatic stack adjustors
adjust themseives during full brake applications,
thoy must be checked.
Automatic adjusters should net have to be
manually adjusted except when performing
maintenance on the brakes and during installation
of the slack adjusters. In a vehicle equipped with
automatic adjusters, when the pushrod stroke
exceeds the legai brake adjustment limit, it is an
indication that 2 mechanical problem exists in the
adjuster itself, a problem with the related
foundation brake components, or that tae adjuster
was improperly installed.
The manual adjustment of an aviomatic adjuster to
bring a brake pushrod stroke within legal limits is
general’'y masking a mecnarical problem and is
not fixing it. Further, routine adjustmert of most
automatic adjusters will likely result in premature
wear of the adjuster itself. It is recommended that
when brakes equipped with automatic adjusters
ere found to be out of adjustment, the driver take
Section 5 — £ir Erakes
the vehicle {0 a repa’r facility as soon as possible
to have the problem correcied.
The manual adjustment of an automatic acjusler
shoula orly be used as a temporary measure *¢
correct ithe adjustment in an emergency situation
as it is likely the brake will soon be back out of
adjustment since this procedure usually does not
fix the underlying adjustment probiem.
(Note: Automatic slack adjusiers are mace by
different manufacturers ano do not all operate the
same. Therefore, ihe specific manufacturer's
Service Manual should be consulied prior to
troumeshooting a brake adjustment probler.)
Check Braxe Drums (or Discs), Linings, and
Hoses. Brake drums {or discs) must not have
cracks longer than one half the width of the friction
area. ! ininos (friction material) must nat be loose
or soaked with oil or grease. They must not be
dangerously thin. Mechanical parts must be in
place, not broken or missing. Check the air noses
connected to the brake chambers to mare sure
they aren't cut or worn due to rubbing.
5.3.3 - Step 7 Final Air Brake Check
Do the following checks instead of the hydraulic
brake check shown in Section 2 Step 7: Check
Brake System.
Test Low Pressure Warning Signal. Shut tre
engine off when you have enough air pressure 50
thal the low pressure warning signal is not on. Turn
the e:ectrica. power on and step on and off the
brake nedal to reduce air tank pressure. The low
sir pressure warning signal must come on before
the pressure drops to less than 60 psi in the air
tank (or tank with the lowest air pressure, in dua!
air systems). See Figure 5.5.
If the warning signal doesn't work, you could lose
ar pressure and you would not know it. This could
cause sudden emergency braking in a singie-
circuit air sysiem. In dual systems the stopping
cistance will be increased. Only limited braking can
be done before the spring brakes come on.
Page u-6
Commercial Driver's License Manual
a | ‘|
) a Fl
a 1 | } un
en vehicles es are uipped with a
e into the driver's
vien and whl oot tot stoy up In place until
the desired air pressure is restored,
Figure 5.5
Check That Spring Brakes Come On
Automatically, Continue to fan off the air
pressure by stepping on and off the brake pedal to
reduce tank pressure. The tractor protection valve
and parking brake valve should close (pop out) on
a tractor-trailer combination vehicle and the
parking brake valve should close {pop out) on
other combination and single vehicle types when
the air pressure falls to the manufacturer's
specification (20 — 40 psi). This will cause the
spring brakes to come on.
Check Rate of Air Pressure Buildup. When the
engine is at operating rpms, the pressure should
build from 85 to 100 psi within 45 seconds in dual
alr systems. (If the vehicle has larger than
minimum air tanks, the buildup time can be longer
and stil be safe. Check the manufacturer's
specifications.) In single air systems (pre-1975),
typical requirements are pressure buildup from 50
to 90 psi within 3 minutes with the engine at an idle
speed of 600-900 rpms.
If air pressure does not build up fast enough, your
pressure may drop too low during driving, requiring
an emergency stop. Don't drive until you get the
problem fixed.
Test Air Leakage Rate. With a fully-charged air
system (typically 125 psi), turn off the engine,
release the parking brake, and time the air
pressure drop. The loss rate should be less than
two psi in one minute for single vehicles and less
than three psi in one minute for combination
vehicles. Then apply 90 psi or more with the brake
pedal. After the initial pressure drop, if the air
pressure falls more than three psi in one minute for
single vehicles {more than four psi for combination
vehicles), the air loss rate is too much. Check for
air leaks and fix before driving the vehicle.
Otherwise, you could lose your brakes while
Check Air Compressor Governor Cut-in and
Cut-out Pressures. Pumping by the air
compressor should start at about 100 psi and stop
at about 125 psi. (Check manufacturer's
specifications.) Run the engine at a fast idie. The
air governor should cut-out the air compressor at
about the manufacturer's specified pressure. The
air pressure shown by your gauge(s) will stop
rising. With the engine idling, step on and off the
brake to reduce the air tank pressure. The
compressor should сито а! about the
manufacturers specified cutin pressure. The
pressure should begin to rise.
if the air governor does not work as described
above, it may need to be fixed. A governor that
does not work properly may not keep enough air
pressure for safe driving.
Test Parking Brake. Stop the vehicle, put the
parking brake on, and gently pull against it in à low
gear to test that the parking brake will hold.
Test Service Brakes. Wait for normal air
pressure, release the parking brake, move the
vehicle forward slowly (about five mph), and apply
the brakes firmly using the brake pedal. Note any
vehicle “pulling” to one side, unusual feel, or
delayed stopping action.
This test may show you problems, which you
otherwise wouldn't know about until you needed
the brakes on the road.
Section § - Alr Brakes
Page 5-7
Commerciai Driver”s License Manual
Subsections 5,2 and 5.3
Tesi Your Knowledge
What is 2 dual air brake system?
What are the slack adjusters?
How can vou check siack adjusters?
How can you test the low pressure warning
5. low can you chect that the spring brakes
come on automatically?
6. What are the maximum 'eakage rates?
These questions may be on your test. If you can't
answer them all, re-read subseciions 5.2 and 5.3.
5.4 — Using Air Brakes
8.4.1 — Normal! Stops
Push the brake pedal dowr. Controi the pressure
so the vehicle comes to a smooth, safe stop. If you
have a manual transmission, don't push the clutch
in until the engine rpm is dowr close to idle. When
stopned, select a starüng gear.
5.4.2— Braking witis Antitock Brakes
When you brake hard on sl'opery surfaces in a
vehicle without ABS, your wheels may lock up.
When your steering wneels lack up, you lose
steering control. Whei your other wheels lock up,
you may skid, jackknife, or even spin the vehicle.
ABS helps you avoid wheel lock up. The computer
senses impending lockup, reduces the braking
pressure to e safe ‘evel, and you maintain control,
You may or may not de able to stop faster with
ABS, but you should be alle ‘o steer around an
obstacle while braking, and avoid skios caused by
over praking.
Having ABS on only the tractor, only the trailer, o;
even on only one axle, still gives you more contral
over the vehicle during braking. Brake normally.
When only the tracitor has ABS, you should be able
to maintain steering control, and there is iess
chance of jackknifing. But, keep your eye on the
traiier and let up on the brakes (i you can safely do
so) if it begins To swing ous.
Wher only the trailer has ABS, tha trailer is less
likely to swi”g out, but r you ose steering control
or start a tractor jackkni‘e, let up on the brakes (if
you car safely do so) until you gain contro:
When you drive a tractor-trailer combination with
ABS, you should brake as you always eve. in
other words:
Use only the brzking force necessary to ston safely
and stay in control.
Brake the same way, regardiess of whether you
have ABS on the tractor, the trailer, or both,
As you slow down, moritor vour tracici and treile-
and heck of the brakes {if it is safe to do so) to
stay in control.
There is only one exception to this procedure, if
you always drive a straight truck or combinetion
with working ABS on all axles, in an emergency
stop, you can fully apply the brakes.
Without ABS, you still have rormal brake functions.
Drive and brake as you always have.
Remember, if your ABS malfunctions, you still
have regular brakes. Drive normally, but get the
system selviced soon.
54,3 — Emergency Stons
If somebody suddenly pulls aut in front of you, your
natural resnonse is to nit the brakes. This is a good
response if there's enough distance to stop, and
you use the brakes correctly.
You should brake In a way that will keen your
vehicle in a straight line and allow you io turn if it
becomes necessary. You can use the “controled
braking” methoa oi the "stab braking” method.
Controlled Braking. With this method, you apply
the brakes as hard as you can without locking the
wheels. Keep steering wheel movements very
smal! while doing this. If you need to make a larger
steering adjustment or if the wheels lock, release
the brakes. Re-apyly the brakes as soon as you
Stab Braking
App y your brakes al. the way.
Release brakes wher whee's lock up.
As soon as ihe whees start rolling, apply the
brakes fully again. (it can take up to one second
for the \ heels to start rolling afer you: release the
brakes. !f you re-apply the brakes before the
wheels start rolling, the vehicle won't straighten
Section 5 - Air Brakcs
Paga 3-3
Commercial Drivers License Manual
5.4.4 — Stopping Distance
Stopping distance was described in Section 2
under “Speed and Stopping Distance. With air
brakes there is ar added delay--the time required
for the brakes to work afler the brake pedal is
pushed. With hydrauiic brakes (used on cars and
fight/mecium trucks), the brakes work instantly.
However, with air brakes, it takes a little time {one
half second or more} for the air to flow through the
lines to the brakes. Thus, the tota: stoppino
distance for vehicles with air brake systems is
made up of four differert factors.
Perception Distance + Reaction Distance + Brake
Lag Distance + Effective Braking Distance = Total
Stopping Distance
The air brake lag distance at 55 mph on dry
pavement adds about 32 feet. So at 55 mph for an
average driver under good traction and brake
conditions, the total stopping distance is over 450
feet. See Figure 5.6.
Stopping D'stance Chart
Wiles Per | How Far | Drive. Venicle Total
Hour The Ry | Reac:ion | Eraking Stopp ng
Will Distance | Distance | Distance
Travel in |
15mph ‘22. 17 ft. 29 ft. ES FL
20 mph 44 fi. 33 ft. 115 fi. 148 ft.
45 mph 86 it. 50 ft, 260 fi. 310 ft
50 mph 73H. 55 ft. 320 ft. 375 ft
55 mph 81 4 61 ñ 390 fi. 451 ft,
Figure 5.€
5.4.5 — Brake Fading or Failure
Brakes are designed so brake shoes or pads rub
against the brake drum or disks to slow the vehicle.
Braking creates heat, bul brakes are designed to
take a lot of heat. However, brakes can fade or fail
from excessive heat caused by using them too
much and not relying on the engine braking effect.
Excessive use of the service brakes results in
overheating and leads ¡0 brake fade. Brake fade
resuts from excessive heet causing chemical
changes in the brake lining, which reduce friction,
ana also causing expansion of the brake drums.
As the overheated drums expand, the brake shoes
and linings have to move farther to contact the
drurns, and the force of this contact is reduced.
Continued overuse mav increase brake fade until
the vehicle cannot be slaved dovn or stopped.
Brake fade is also affected by adjustment. To
safely control a venicle, every brake must do js
share of ine work. Brakes out of adjustment will
stop doing their share before those that are in
adjustment. The other brakes can then overheat
and fade, and there will not be enough brakiag
available to conirol the vehicle(s). Brakes can get
out of adjustment quickly, especially when they are
hot. Thereícre, cieck brake adiustment often.
3.4.6 - Propar Sraking Technicue
Remember. The use of brakes on a long and/or
steep downgrade is only a supplement to the
braking effect of the engine. Once the vehicle is in
the prope: low gear, the following is the proper
braking technigue:
Annly the brakes just nard enough to feel a definite
When your speed has been reduced to
approximate.:y five mph below your “safe" speed,
release the brakes. (This application should last for
about three seconds.)
When your speed has increased to your “safe”
speed, repeat steps 1 and 2.
For example, if your “safe” soeed is 40 mph, you
wou'c not apply the brakes until your speed
reaches 40 mph. You now apply the >raxes hard
enough to gradually reduce your speed to 35 mph
and then release the brakes. Repeat th's as often
as necessary until you have reached the end of the
5.4.7 « Low Air Pressure
If the low air pressure warring comes on, stop and
safely park your vehicle as soon as possible. There
might be an air leak in the system. Controlied
braking is possible only while enough air remains
in the air tanks. The spring brakes will come on
when the zir pressure drops into the range of 20 to
45 psi. A neavily loaded vehicle will take a jong
distance fo stop because the spring brakes do not
work on all axes. Lightly loaded venicles or
vehicles on slippery roads may skid out of control
when the spring brakes come on. it is much safer
to stop while there is enough air in the tanks to use
tre foot brakes.
5.6.8 Parking Prekes
Any time you park, use the parking brakes, except
as noted velow. Pull the parking brake control
knob out to anply the narking brakes. push it in 1o
release. The control will be a yellow, diamerd-
shaped krob labeled “parking brakes” on rewer
Section 5 - Air Brakes
Page 5-8
Commercia; Driver's License Manual
vehicles. On older vehicies, it may be a round blue
knob or seme other shape (inciuding a lever that
swings frora side to side or up and down).
Dont use the parking brakes if the brakes are very
kot (from just having come down a steep grade), or
ir the brakes cre very wet in freezing temperatures.
If they are used wile they are very hol, they can
be damaged by the heat. ¥ they are used in
freezing temperatures when the brakes are very
wel, they can fresze so the vehicle cannot move.
Use wheel chocks on a level surface to hold the
vehicie. Let hat brakes cool before using the
parking brakes. If the brakes are wei, use the
orakes lighlly while driving in a low gear to heat
and dry them.
if your vehicle does not have automatic air tank
drains, drain your ar tanks at the end of each
working day to remove moisture and oi.
Otherwise, the brakes could fail.
Never leave your vehicle unattendeo
without applying the parking brakes or
chocking the wheels. Your vehicle mighi
roll away and cause injury and damage.
Supsectiaon 5.4
Test Your Knowledge
1. Why should you be in the proper gear before
starting down a hill?
2. What factors can cause brakes to fade or
3. The use of brakes on a long, steep
cowngrade is only 2 supp'ement to the
braking effect of the engine. True or False?
4. If you are away from your vehicle only a short
time, you do not need to use the parking
brake. True or False?
5. Hov: often sHould you vcrain air tanks”?
6 How do you brake when you drive a vactor-
trailer combination with ABS?
7. You stil have normal brake functions if your
ABS is not working. True or False?
These questions may be on your test. IT you can't
answer them ali, re-read subsection 5.4.
Section 3 — Air Brakes Page 5-10
Commercial Driver's License Manual
Me EEE LA 4 ET E] je y E A gE E
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Zen Mc Mayo
This Section Covers
« Sriving Combinations
« (ombination Venicie Air Brakes
e Antiiock Brake Sysiems
> Coupling and Uncoupling
a Inspecting Combinations
This section provides information needed to pass
the tesis for combination vehicies (iractor-trailer,
doubles, triples, straight truck with trailer). The
information is only to give you the minimum
knowledge needed for driving common
combination vehicles. You should aiso study
Section 7 if you need to pass the test for doubles
and triples.
6.1 -- Driving Combination Vehicies
Combinaticn vehicles are usualy heavier, longer,
and require more driving skill than single
commercial vehicles. This means that drivers of
combination vehicles need more knowledge and
skil than drivers of single vehicles. in this section,
we talx about some important safety factors that
apply specifically to combination vehicles.
6.7.7 — Rollover iZisks
More than half of truck driver deaths in crashes are
the result of truck rollovers. When more cargo is
piled up in a truck, the “center or gravity moves
higher up from the road. The truck becomes easier
io tum over. Fully 'oaded rigs are ten times more
likely to roll over in a crash than empty rigs.
The following two things will help you prevent
rollover-keep the cargo as close to the ground as
possible, and drive slowly around turns. Keeping
cargo low is even more important in combination
vehicies than in straight trucks. Also, keep the load
centered on your rig. I the load is to one side so it
makes a trailer iean, a rollover is more likely. Make
sure your Cargo is centered ang spread oul as
rauch as possible. (Cargo distribution is covered ii
Section 3 of this manual}
Rollovers happen wher you turn too fest. Drive
sioviy around corners, on ramps, and off ramps.
Avoid quick lane changes, especially when fully
6,72 - Steer Gentiy
Trucks with trailers have a dangerous “crack-the-
wiip” effect. When you make a quier lane change,
the crack the-whip effect can urn the trailer over.
There arc many accidenis where ony the trailer
has overturned.
‘Rearward ampiification” causes the crack-the-
whip effect. Figure 6.1 shows eight types of
combination vehicles and the rearward
amplification sach has In 8 quick ‘ane change.
Rigs with ihe ieast crack-the-whin effect are shown
at the top anc those with the most, at the bottom.
Rearward amplification of 2.0 in the chart means
that the rear traier is tice as likely to tun over as
the tractor. You can see that iripies have a
reaiward amplification of 3.5. This means you can
rolf the last trailer of triples 3.5 times ac easily as a
five -ax.e tractor.
Steer gently and smoothly when you are puiing
trailers. If you maxe a sudden movement with your
steering wheel, your traiter coulé tip over. Follov:
far enough behind other vehicles (at least 1
second for each 10 feet of your vehicle length, plus
another second if going over 40 mph). Loox far
enoug” down the road to avoid being suiprised
and having to make a sucden lane change. At
night, crive slowy enough to see obstacles with
your headlights before it is too late to change lanes
or stop gently. Slow down to a safe speed before
going into a turn.
6.1.3 -- Grake Early
Control your speed whether fully loaded or empty,
Large combination vehicies take longer to stop
when they are empty than when they are fully
loaded. When lightly loaded, the very stiff
suspension springs and sirong brakes give poor
traction and make it very easy to lock up the
wheels. Your traiier can swing out and strike other
vehicles. Your tractor can jackknife very quickly.
You also must be very careful about diving
"bobtail” tractors (tractors without semitraiers).
Tests have shown that bobtails can be very hard to
stop smcothy. It takes them longer to stop than a
tractor-semitrailer foadeu lo maximum gross
In any combination rig, alow lots of following
distance and look far ahoad, so you cen brake
ear:y. Don: be caught by surprise anc have to
make a “panic” stop.
Section 6 - Combination Ve Ces
Раде 6-1
Commercial Drivers License Manual
10 15 20 25 30 as 40
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Figure 6.1
5.1.4 - Railroad-highwey Crossings
Railroad-highway crossings can aso cause
sroblems, particularly when pulling trailers with low
underneath clearance.
These trailers can get siuck on raised crossings:
ow slung units (lowboy, car carrier, Moving van,
possum-belly livesteck trailer).
Sing:e-axle tractor pliling a long trailer with iis
landing gear set to accommodate a tandem-axle
if for any reason vou get stuck on the tracks, get
out of the vehicle and away from the tracks. Check
signposis or signa: housing at the crossing for
emergency notification information. Call 811 or
other emergency number. Give the location of the
crossing using al identifiable landmariks, especially
the DOT number, ir posted.
6.1.5 .- Prevent Trailer Sicids
When the wheels of a trailer lock up, the trailer will
tend to swing around. This is more likely to happen
when the trailer is empty or lightly loaded. This
type of jackknife is often called a "trailer jackinife.
See Figure 6.2.
The procedure for stonping a traile: skid is:
Kecognize the Skid. The earliest and best way to
recognize that the trailer has started to skid is by
seeing “t in your mirrors. Ary time you apply the
brakes hard, check the mirrors to make sure the
taler is siayind where it should be. Once the
trailer swings out of your lane, it's very difficuli to
prevent a jackknifre.
12. (From К.О, Ervin, R.L. Nisconger, C.C.
MacAdant, aad P.S. Fancher, “Influence of
size anu weigh variables on the stability
and contro! properties of heavy irucks,
University of Michigan Transportation
Rescarch Institute, 1983).
Section 6 - Combination Velie es
Commercial Driver's License Manual
toot Travel
Taller Wheels
Locked-Up a
And Sliding
Figure 6.2
Stop Using the Brake. Release the brakes to get
traction back. Do not use the trailer hand brake (if
you have one) to "straighten out the rig.” This is the
wrong thing to do since the brakes on the trailer
wheels caused the skid in the first place. Once the
trailer wheels grip the road again, the trailer will
start to follow the tractor and straighten out.
6.1.6 — Turn Wide
When a vehicle goes around a corner, the rear
wheels follow a different path than the front
wheels. This is called offtracking or “cheating.”
Figure 8.3 shows how offtracking causes the path
followed by a tractor to be wider than the rig itself.
Longer vehicles will offtrack more. The rear wheels
of the powered unit (truck or tractor) will offtrack
some, and the rear wheels of the trailer will offtrack
even more. If there is more than one trailer, the
rear wheels of the last trailer will offtrack the most.
Steer the front end wide enough around a corner
so the rear end does not run over the curb,
pedestrians, etc. However, keep the rear of your
vehicle close to the curb. This will stop other
drivers from passing you on the right. if you cannot
complete your turn without entering another traffic
lane, turn wide as you complete the turn. This is
better than swinging wide to the left before starting
the turn because it will keep other drivers from
passing you on the right. See Figure 6.4.
Path follows by the Eursrrocot tira
Рай бойко ций Блу these ооо Этот а
Figure 6.3
fraps a =
ый 4
| нау щи, a IE
Figure 6,4
6.1.7 — Backing with a Trailer.
Backing with a Trailer. When backing a car,
straight truck, or bus, you turn the top of the
steering wheel in the direction you want to go.
When backing a trailer, you turn the steering wheel
in the opposite direction. Once the trailer starts to
turn, you must turn the wheel the other way to
follow the trailer.
Whenever you back up with a trailer, try to position
your vehicle so you can back in a straight line. If
you must back on a curved path, back to the
driver's side so you can see. See Figure 6.5.
‘Section 6 - Combination Vehicles
Page 6-3
Commercial Driver's License Manual
Figure 6.5
Look at Your Path. Look at your line of travel
before you begin. Get out and walk around the
vehicle. Check your clearance to the sides and
overhead, in and near the path your vehicle.
Use Mirrors on Both Sides. Check the outside
mirrors on both sides frequently. Get out of the
vehicle and re-inspect your path if you are unsure.
Back Slowly. This will let you make corrections
before you get too far off course.
Correct Drift Immediately. As soon as you see
the trailer getting off the proper path, correct it by
turning the top of the steering wheel in the
direction of the drift.
Pull Forward. When backing a trailer, make pull-
ups to re-position your vehicle as needed.
Subsection 6.1
Test Your Knowiedge
1. What two things are important to prevent
2. When you turn suddenly while pulling
doubles, which trailer is most likely to turn
3. Why should you not use the trailer hand
brake to straighten out à jackknifing trailer?
4. What is offtracking?
5. When you back a trailer, you should
position your vehicle so you can back in a
curved path to the driver's side. True or
6. What type of trailers can get stuck on
railroad-highway crossings?
These questions may be on your test. If you can't
answer them all, re-read subsection 6.1.
6.2 — Combination Vehicle Air Brakes
You should study Section 5: Air Brakes before
reading this. In combination vehicles the braking
system has parts to control the trailer brakes, In
addition to the parts described in Section 5. These
parts are described below.
6.2.1 — Trailer Hand Valve
The trailer hand valve (also called the trolley valve
or Johnson bar) works the trailer brakes. The trailer
hand valve should be used oniy to test the trailer
brakes. Do not use it in driving because of the
danger of making the frailer skid. The foot brake
sends air to all of the brakes on the vehicle
(including the trailer(s)}. There is much less danger
of causing a skid or jackknife when using just the
foot brake.
Never use the hand valve for parking because all
the air might leak out unlocking the brakes (in
trailers that don't have spring brakes). Always use
the parking brakes when parking. If the trailer does
not have spring brakes, use wheel chocks to keep
the trailer from moving.
6.2.2 — Tractor Protection Valve
The tractor protection valve keeps air in the tractor
or truck brake system should the traiier break away
or develop a bad leak. The tractor protection valve
Section 6 - Combination Vehicles
Page 6-4
Commercial Drivers License Manual
is controlled by the "trailer air supply” contro! valve
in the cab. The contiol valve allows you to open
and shut the tractor protection valve. The tractor
protection valve will close automatically # air
pressure is low (in the range of 20 to 45 psi), Wien
the tractor protection valve cioses, it stops any air
from going out of the tractor. it also iets the air out
of the trailer emergency ne. This causes the trailer
emergency brakes {o come on, wilh possible loss
of control. (Emergency brakes are covered later.)
6.2.3 -- Trailer sir Supply Control
The trailer air supply control on newer vehicles is a
red eight-sided knob, which you use to control the
tractor protection valve. You push it in to supply the
trailer with air, and pul: it out to shut the air off and
put on the trailer emergency brakes. The valve will
pop out (thus closing the tractor protection valve)
whan the air pressure drops into the range of 20 to
£5 nsi. Tractor protection valve contras or
“emergency” valves on older vehicies may not
operate automatically. “here may be a lever rather
than a knob. The "normar position is used for
pulling a trailer. The “emergency” position is used
io shut the air off and put on the tra:er emergency
6.2.4 — Traiter Air Lines
Every combination vehicie has two air lines, the
service line and the emergarcy ine. They run
between each vehicle (tractor to trailer, trailer to
dolly, dolly to second trailer, etc.)
Service Air Line. The service line (also celled the
control lire or signal line} carries air, waich is
controlled by the foot brake or the trailer hand
brake. Depending on how hard you press the foot
brake or hand valve, the nressure in the service
line will similarly change. The service line is
connecied to relay vaives. These valves allow the
trailer brakes to be applied more quicky than
would otherwise be possibie.
Emergency Air Line. The emergency line (also
called the supply line} has two purposes. First, it
supplies air to the trailer air tanks. Secord, the
emergency ne controls the emergency brakes on
combination vehicles. Loss of air pressure in the
emergency fine causes the traller emergercy
brakes to come or. The pressure 0ss could be
caused by @ trailer Creaking loose, thus tearing
apart the emergency air hose. Or it could be
caused by a nose, metal tubing, or other part
breaking, letting the air out. Wher. the emergency
fine loses nressure, № also causes the tracior
protection valve to close (the air supply “rob wi:
pop out).
Emergency lines are often coded with the color red
(red hose, red couplers, or other parts) to keep
from getting them mixed up with the blue service
6.2.5 — Hose Couplers (Glad Hands)
Glau hards are coupling devices used to connect
tie service and emergency air lines from the truck
or tractor to “he trailer. The couplers have a rubber
seal, which prevertis air from escaping. Clean the
couplers and rubber seals before a connection is
made. When conneciing te glad hanus, press the
two seals logether with the couplers at a 90 degree
angle to eac: other. A turn of the glad hand
attachec to the hose will join and lock the couplers.
When coupling, make sure to couple ihe proper
glad hands iogether. Ta help avoid mistakes,
colors are sometimes used. Blue is used fo” the
service lines and red for the emergency (supply)
lines. Sometimes, meta! tags are attached to the
ines vith the vords “service” and “emergency”
stamped on them. See Figure 6.6
If you do cross the air litres, supply air will be sent
to the service line instead of going to charge the
trailer air tanks. Air will not be available to release
the trailer spring brakes (parking brakes). the
spring brakes dont release when you push the
trailer air supply control, check the air line
Older trailers do not have spring brakes. If the air
supply in the traiter air tanx has leaked away there
wil be no emergency brakes, and the traier
wheels will turn freely. If you crossed the air lines,
you could drive away but you wouldn't have trailer
brakes. This would be very dangerous. Always test
the trailer brakes before driving with the hand valve
or by puiling the air supply (tractor protection valve)
control. Pull gently against them in à ow gear to
make sure the brakes work.
Some venicles have “dead end" or dummy
couplers io which the hoses may be attached
when they are not in use. This will prevent water
and dirt from getting into the coupier and the air
lines. Use tre dummy couplers when the air lines
are nut cennecied to 2 trailer. if there are no
dummy couplers, the glac nands can sometimes
be locked together (depending on the couviings). It
is very important to keep the air supply clean.
Seciion & - Combing: or Vehicies
Page 6-5
Commercial Driver's License Manual
Trailer Line
Truck Line
Figure 6.6
6.2.6 — Trailer Air Tanks
Each trailer and converter dolly has one or more
air tanks. They are filled by the emergency (supply)
line from the tractor. They provide ihe air pressure
used to operate trailer brakes. Air pressure is sent
from the air tanks to the brakes by relay valves,
The pressure in the service line tells how much
pressure the relay valves should send to the trailer
brakes. The pressure in the service line is
controlled by the brake pedal (and the trailer hand
It is important that you don't let water and oil build
up in the air tanks. If you do, the brakes may not
work correctly. Each tank has a drain valve on it
and you should drain each tank every day. If your
tanks have automatic drains, they will keep most
moisture out. But you should still open the drains to
make sure.
6.2.7 ~ Shut-off Valves
Shut-off valves (also called cut-out cocks) are used
in the service and supply air lines at the back of
trailers used to tow other trailers. These valves
permit closing the alr lines off when another trailer
is not being towed. You must check that all shut-off
valves are in the open position except the ones at
the back of the last trailer, which must be closed.
6.2.8 — Trailer Service, Parking and
Emergency Brakes
Newer trailers have spring brakes just like trucks
and truck tractors. However, converter dollies and
trailers built before 1975 are not required to have
spring brakes. Those that do not have spring
brakes have emergency brakes, which work from
the air stored in the trailer air tank. The emergency
brakes come on whenever air pressure in the
emergency line is lost. These {trailers have no
parking brake. The emergency brakes come on
whenever the air supply knob is pulled out or the
trailer is disconnected. A major leak In the
emergency line will cause the tractor protection
vaive to close and the trailer emergency brakes to
come on. But the brakes will hold only as long as
there is air pressure in the trailer air tank.
Eventually, the air will leak away and then there
will be no brakes. Therefore, it is very important for
safety that you use wheel chocks when you park
trailers without spring brakes.
You may not notice a major leak in the service line
until you try to put the brakes on. Then, the air loss
from the leak will lower the air tank pressure
quickly. IF it goes low enough, the trailer
emergency brakes will come on.
Ee a ==
Subsection 6.2
Test Your Knowledge
1. Why should you not use the trailer hand
valve while driving?
Describe what the trailer air supply control
Describe what the service line is for.
What is the emergency air line for?
Why should you use chocks when parking
a trailer without spring brakes?
Where are shut-off vaives?
These questions may be on your test. !f you can't
answer them all, re-read subsection 6.2,
— —
—— —н——— —
Section 6 - Combination Vehicles
Page 6-6
Commercial Drivers License Manual
6.3 — Antilock Brake Systems
6.3.1 — Trailers Required to Have ABS
AN trailers and converter dollies built on or after
March 1, 1998, are required to have ABS.
However, many trailers and converter dollies built
before this date have been voluntarily equipped
with ABS.
Trailers will have yellow ABS malfunction lamps on
the left side, either on the front or rear corner. See
Figure 86.7. Dollies manufactured on or after March
1, 1998, are required to have a lamp on the left
In the case of vehicles manufactured before the
required date, it may be difficult to tell if the unit is
equipped with ABS. Look under the vehicle for the
ECU and wheel speed sensor wires coming from
the back of the brakes.
Back of Semitruek Trailer
ABS Test Light
Figure 6.7
6.3.2 — Braking with ABS
ABS is an addition to your normal brakes. it does
not decrease or increase your normal braking
capability. ABS only activates when wheels are
about to lock up.
ABS does not necessarily shorten your stopping
distance, but it does help you keep the vehicle
under control during hard braking.
ABS helps you avoid wheel lock up. The computer
senses impending lockup, reduces the braking
pressure to a safe level, and you maintain control.
Having ABS on only the trailer, or even on only
one axle, still gives you more control over the
vehicle during braking.
When only the trailer has ABS, the trailer is less
likely to swing out, but if you lose steering control
or start a tractor jackknife, let up on the brakes (if
you can safely do so) until you gain control.
When you drive a tractor-trailer combination with
ABS, you shouid brake as you always have. In
other words:
Lise only the braking force necessary to stop safely
and stay in control.
Brake the same way, regardless of whether you
have ABS on the tractor, the trailer, or both.
As you slow down, monitor your tractor and trailer
and back off the brakes (if it is safe to do so) to
stay in control.
Remember, if your ABS malfunctions, you still
have regular brakes. Drive normally, but get the
system serviced soon.
ABS won't allow you to drive faster, follow more
closely, or drive less carefully.
6.4 - Coupling and Uncoupling
Knowing how ta coupie and uncouple correctly is
basic to safe operation of combination vehicles.
Wrong coupling and uncoupling can be very
dangerous. Generai coupling and uncoupling steps
are listed below. There are differences between
different rigs, so learn the details of coupling and
uncoupling the truck(s) you will operate.
6.4.1 - Coupling Tractor-Semitrailers
Step 1. inspect Fifth Wheel
Check for damaged/missing parts.
Check to see that mounting to tractor is secure, no
cracks in frame, etc.
Be sure that the fifth wheel plate is greased as
required. Failure to keep the fifth wheel plate
lubricated could cause steering problems because
of friction between the tractor and trailer.
Section 8 - Combination Vehicles
Page 6-7
Commercial Driver's License manual
Check if fifth wheel is in proper position for
= Whee! tilted down toward rear of tractor.
” Jaws open.
> Safety unlocking handle in the automatic ‘ock
„ |f you have a sliding fifth wheel, make sure it
is locked.
r Make sure the trailer kingpin is not bent or
Step 2. inspect Area and Chocx Wheels
Make sure area around the vehicle is clear.
Be sure trailer wnees are chocked ar spring
brakes are on.
Check that cargo (if any) is secured against
movement due to tactor being coupied to the
Step 3. Position Tractor
Put the tractor directly in front of the trailer. (Never
back under the trailer at an angle because you
might push the fraier sideways and break the
‘anding gear.)
Check position, using outside mirrors, by looking
down both sides of {he traller.
Step 4. Back Slowiy
Back until fifth wneel just :ouches the trailer.
Don't hit the traiier.
Step 5, Secure Tractor
Put on the parking brake. .
Put transmission in neutral.
Step 6. Check Trailer Height
The trailer shou'c be low erough that it is reised
slichtly by the tractor when the tractor is backed
under it. Raise or iower the tralier as needed. (If
the trailer is too low, the tractor may strike anc
damage the trailer nose; if the trailer is too high, it
may not coup.e correctly.)
Check ihat the ki
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