NV_Non-CDLManual
Nevada
Non-Commercial
Class A and B
Study Guide
May 2010
Table of Contents
Foreword.....................................................................................................4
General Information ..................................................................................................................4
Non-Commercial Vehicle Classifications ..................................................................................4
What You Need To Know… ......................................................................................................5
Section 1 - Driving Safely ..........................................................................6
Basic Control of Your Vehicle ...................................................................................................6
Accelerating ..........................................................................................................................6
Shifting Gears .......................................................................................................................6
Controlling Speed..................................................................................................................7
Steering...............................................................................................................................11
Braking ................................................................................................................................14
Be Aware of Your Surroundings..............................................................................................16
Looking Ahead ....................................................................................................................16
Use Your Mirrors .................................................................................................................16
Signal Your Intentions .........................................................................................................17
Communicate Your Presence .............................................................................................18
Managing Space .....................................................................................................................20
Space ahead .......................................................................................................................20
Space behind ......................................................................................................................20
Space to the sides...............................................................................................................21
Space overhead ..................................................................................................................22
Space needed to cross or enter traffic ................................................................................23
Driving at Night .......................................................................................................................24
Driver Factors......................................................................................................................24
Roadway Factors ................................................................................................................24
Vehicle Factors ...................................................................................................................25
Driving in Winter......................................................................................................................25
Driving in Very Hot Weather....................................................................................................26
Seeing Hazards ......................................................................................................................28
Importance of Seeing Hazards............................................................................................28
Hazardous Roads ...............................................................................................................28
Drivers Who Are Hazards ...................................................................................................28
Emergencies ...........................................................................................................................29
Tire Failure ..........................................................................................................................29
Skid Control and Recovery .................................................................................................30
Accident Procedures ...........................................................................................................32
Fires ....................................................................................................................................32
Staying Alert and Fit to Drive ..................................................................................................34
Section 2 - Transporting Cargo Safely...................................................38
Inspecting and Securing Cargo...............................................................................................38
Inspecting your cargo..........................................................................................................38
Weight and balance ............................................................................................................38
Section 3 - Air Brakes ..............................................................................40
The Parts of an Air Brake System...........................................................................................40
Dual Air Brakes .......................................................................................................................44
Walk-Around Inspection ..........................................................................................................45
Final Air Brake Check .........................................................................................................45
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Using Air Brakes .....................................................................................................................47
Section 4 - Combination Vehicles ..........................................................50
Rollover risks ..........................................................................................................................50
Brake early ..............................................................................................................................51
Prevent trailer skids ................................................................................................................51
Recognizing the skid ...........................................................................................................51
Stop using the brake ...........................................................................................................52
Section 5 - Pre-Trip Vehicle Inspection Test .........................................53
All Vehicles .............................................................................................................................53
Engine Compartment Only..................................................................................................53
Cab Check/Engine Start......................................................................................................54
Air Brake Check (if equipped) .............................................................................................54
Light/Reflectors ...................................................................................................................55
Wheels ................................................................................................................................55
Tractor/Coupling..................................................................................................................55
Trailer ..................................................................................................................................56
Section 6 - Basic Vehicle Control Skills Test ........................................57
Scoring....................................................................................................................................57
Exercises ................................................................................................................................57
Section 7 - On-Road Driving Test ...........................................................59
Exercises ................................................................................................................................59
Clutch Usage (manual transmission) ..................................................................................59
Gear Usage (manual transmission) ....................................................................................59
Brake Usage .......................................................................................................................59
Lane Usage.........................................................................................................................59
How You Will Be Tested .........................................................................................................60
Turns ...................................................................................................................................60
Intersections........................................................................................................................60
Curve...................................................................................................................................62
Upgrade ..............................................................................................................................62
Downgrade..........................................................................................................................62
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Foreword
General Information
The vehicles in the non-commercial classification are generally vehicles that are used for
recreational purposes, or may include certain rental vehicles that meet the criteria of the below
license classifications. However, trucks, buses, and vehicles operating at heavier weights are
subject to certain laws, regulations, and restrictions that can vary from place to place.
You do not need a commercial driver’s license to operate some vehicles that fall within the
Gross Vehicle Weight Rating (GVWR) descriptions. The following are exempt from Nevada
commercial driver’s licensing requirements:
• Farmers transporting equipment, supplies, or products to or from a farm as long as the
vehicle is:
o
o
o
o
Controlled and operated by a farmer, his family members, or employees;
Used within 150 miles of the farm;
Not being used as a common or contract motor carrier; or
Not transporting placarded amounts of hazardous materials.
• Active duty military personnel driving a military vehicle
• Firefighters operating emergency equipment
If you qualify for this exemption, you may apply for an “F” endorsement on your Nevada driver’s
license.
Non-Commercial Vehicle Classifications
Class A
May drive any combination of vehicles with a gross combination weight rating
(GCWR) of 26,001 or more pounds, provided the vehicle being towed has a
gross vehicle weight rating (GVWR) of more than 10,000 pounds; or
Any combination of vehicles not exceeding 70 feet in length with a gross
combination weight rating of 26,000 pounds or less so long as the gross
combination weight rating of the towed vehicles does not exceed the gross
vehicle weight rating of the towing vehicle.
Class B
May drive any single vehicle with a gross vehicle weight rating of 26,001 or more
pounds, or any vehicle which is towing another vehicle which does not have a
gross vehicle weight rating of more than 10,000 pounds.
Class C
May drive any single vehicle or combination of vehicle that does not meet the
definition of Class A or Class B. May include a low-speed vehicle, moped or a trimobile.
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What You Need To Know…
If You Are Applying For This
Study This
Class A License
Section 1, Driving Safely
Section 2, Transporting Cargo Safely
Section 4, Combination Vehicles
Section 5, Pre-trip Inspection
Section 6, Basic Skills
Section 7, Drive Test
Class B License
Section 1, Driving Safely
Section 2, Transporting Cargo
Section 5, Pre-trip Inspection
Section 6, Basic Skills
Section 7, Drive Test
Any vehicle equipped with air brakes
Section 3, Air brakes
Written tests can be taken at all offices.
Drive tests are administered at the following offices:
555 Wright Way, Carson City
3920 East Idaho Street, Elko
178 North Avenue F, Ely
4110 Donovan Way, North Las Vegas
810 East Greg Street, Sparks
1137 South Main Street, Tonopah
3505 Construction Way, Winnemucca
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Section 1 - Driving Safely
Basic Control of Your Vehicle
To drive a vehicle safely, you must be able to control its speed and direction. Safe operation of
a vehicle requires skill in:
•
•
•
•
•
Accelerating
Shifting Gears
Controlling Speed
Steering
Braking
You should wear your seat belt in a moving vehicle at all times and apply your parking brake
when you leave your vehicle.
Accelerating
Rough acceleration can cause mechanical damage. When pulling a trailer, rough acceleration
can also damage the coupling. Start out smoothly and speed up gradually so the vehicle does
not jerk. If you are starting your vehicle in motion from a stop and you apply power to the drive
wheels and they begin to spin, take your foot off the accelerator.
If the vehicle has a manual transmission, don’t roll back when you start. You may hit someone
or something behind you. Partly engage the clutch before you take your right foot off of the
brake. If you have to stop on an uphill grade, use the parking brake to hold the vehicle until the
clutch engages. Release the parking brake only when you have applied enough engine power
to keep from rolling back.
Shifting Gears
It is important to shift gears correctly to keep control of the vehicle. If you can’t get your vehicle
into the right gear while driving, you will have less control.
Manual Transmission
Basic method for shifting up – Most heavy vehicles with manual transmissions require double
clutching to change gears. This is the basic method:
1. Release accelerator, push in clutch and shift to neutral at the same time.
2. Release clutch.
3. Let engine and gears slow down to the RPM required for the next gear (this takes
practice).
4. Push in clutch and shift to the higher gear at the same time.
5. Release clutch and press accelerator at the same time.
Shifting gears using double clutching requires practice. If you remain too long in neutral, you
may have difficulty putting the vehicle into the next gear. If so, don’t try to force it. Return to
neutral, release clutch, increase engine speed to match road speed, and try again.
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Knowing when to shift – There are two ways of knowing when to shift:
1. Engine speed (Revolutions Per Minute or RPM). Study the driver’s manual for your
vehicle and learn the operating RPM range. Watch your tachometer, and shift up when
your engine reaches the top of the range.
2. Road speed (Miles Per Hour or MPH). Learn what speeds each gear is good for. By
using the speedometer, you’ll know when to shift up.
With either method, you may learn to use engine sounds to know when to shift.
Basic method for shifting down
1. Release accelerator, push in clutch and shift to neutral at the same time.
2. Release clutch.
3. Press accelerator, increase engine and gear speed to the RPM required in the lower
gear.
4. Push in clutch and shift to lower gear at the same time.
5. Release clutch and press accelerator at the same time.
Downshifting, like upshifting requires knowing when to shift. Use either the tachometer or the
speedometer and downshift at the right RPM or road speed.
Special conditions where you should downshift are:
• Starting down a hill – Slow down and shift down to a speed that you can control
without using the brakes hard. Otherwise, the brakes can overheat and lose their
braking power.
• Entering a curve – When you downshift for a curve, you should do so before you enter
the curve. Slow down to a safe speed and shift down to the correct gear. This lets you
use some power through the curve to help the vehicle be more stable while turning. It
also lets you speed up as soon as you are out of the curve.
Multi-Speed Rear Axles
Multi-speed rear axles and auxiliary transmissions are used on many vehicles to provide extra
gears. They are generally controlled 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.
Automatic Transmissions
Some vehicles have automatic transmissions. You can select a low range to get greater engine
braking when going down grades. The lower ranges prevent the transmission from shifting up
beyond the selected gear (unless the governor RPM is exceeded). It is very important to use
this braking effect when going down grades.
Controlling Speed
Stopping distance
The primary cause of fatal crashes is driving too fast. The speed at which you drive should be
determined by your visibility and other driving conditions. These include traction, curves, traffic,
and hills.
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There are three things that add up to total stopping distance:
+
+
Perception Distance
Reaction Distance
Braking Distance
=
Total Stopping Distance
Perception Distance 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
¾ second. You will travel 60 feet in ¾ second at 55 mph.
Reaction Distance is the distance traveled from the time your brain tells your foot to
move from the accelerator until your foot is actually pushing the brake pedal. The
reaction time of an average driver is about ¾ second. You will travel an additional 60
feet in ¾ second at 55 mph.
Braking Distance is the distance it takes to stop once the brakes are applied. The
braking time for a heavy vehicle with good brakes is about 4 ½ seconds. You will travel
about 170 feet in 4 ½ seconds at 55 mph.
Total Stopping Distance is the distance you will need to bring a vehicle to a stop. At 55
mph on dry pavement, the total stopping distance is the length of a football field. It will
take about 6 seconds (60 + 60 + 170 = 290 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 greatly increase
stopping distances. Slowing down a little might help prevent an accident.
The effect of vehicle weight on stopping distance
The heavier the vehicle or the faster it is moving, 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. Actually empty trucks
require greater stopping distances, because they have less traction. Also, an empty truck can
bounce and lock up its wheels, giving poorer braking. (This is not usually the case with buses.)
You can’t steer or brake your vehicle without traction. Traction is friction between the tires and
the road. There are some road conditions that reduce traction and call for lower speeds.
Speed and Curves
Drivers must adjust their speed for curves in the road. If you take a curve too fast, two things
can happen. The wheels can lose their traction and continue straight ahead, so you skid off the
road. Or, the wheels may keep their traction and the vehicle rolls over. Tests have shown that
trucks with a high center of gravity can roll over at the posted speed limit for the curve.
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Slow to a safe speed before you enter a curve. Braking in a curve is dangerous because it is
easier to lock the wheels and cause a skid. Slow down as needed. Don’t ever exceed the
posted speed limit for the curve. Be in a gear that will let you accelerate slightly in the curve.
This will help you keep control.
Speed and distance ahead
You should choose a speed that lets you stop within the distance you can see ahead. Fog, rain,
or other conditions may require that you slow down to be able to stop in the distance you can
see. At night, you can’t see as far with low beams as you can with high beams. Slow down
when you must use low beams.
Speed and traffic flow
When you’re driving in heavy traffic, the safest speed is the speed of other vehicles. Vehicles
going the same direction at the same speed are not likely to run into one another. If traffic is
heavy and moving at 35 mph though the speed limit is 55 mph, the safest speed for your vehicle
is most likely 35 mph. Also keep a safe following distance.
The main reason drivers exceed the speed limit is 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 than the speed of other traffic, you have to keep passing other vehicles. This
increases the chance of a crash. It is also more tiring. Fatigue increases the chance of a crash.
Going with the flow of traffic is safer and easier.
Speed on Downgrades
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 lower gears to climb hills or mountains. In coming down long, steep downgrades, gravity
causes the speed of your vehicle to increase. Use a low gear and use proper braking
techniques. The best way to choose a safe speed is based on your vehicle and its cargo. Select
a safe speed that is within the posted speed. If a speed limit is posted or there is a sign
indicating “Maximum Safe Speed,” never exceed the speed shown. Look for and heed warning
signs indicating the length and steepness of the grade.
The principal way you should control your speed going down long and/or steep downgrades is
the braking effect of the engine. The braking effect of the engine is greatest when it is near the
governed RPMs and the transmission is in the lower gears. If you are driving a new truck with a
manual transmission and are taking a long, steep downhill grade, you will probably have to use
a lower gear than you would use to climb the hill. Save your brakes so you will be able to slow
or stop as required by road and traffic conditions.
Shift the transmission to a low gear before starting down the grade. Do not try to downshift after
your speed has already built up. You will not be able to shift into a lower gear. Forcing an
automatic transmission into a lower gear at high speed could damage the transmission and lead
to loss of all engine braking effect.
You must go slowly enough so your brakes can hold you back, if needed, without getting too
hot. If the brakes become too hot, they may start to “fade.” This means you have to apply them
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harder and harder to get the same stopping power. If you continue to use the brakes hard, they
can keep fading until you cannot slow down or stop at all.
It is always important for the brakes to be adjusted right. However, it is especially important
when going down steep grades. If you have a brake modulator, the brake system should be
balanced to give about the same braking at each set of wheels. Otherwise, some brakes will do
more work than others. They will heat up and lose some of their stopping power.
Escape Ramps
Escape ramps have been built on many steep mountain grades. Escape ramps are made to
stop runaway vehicles safely without injuring drivers and passengers and to help avoid damage
to vehicles. Escape ramps use a long bed of loose soft material (pea gravel) to slow a runaway
vehicle, sometimes in combination with an upgrade.
Know escape ramp locations on your route. Signs show drivers where ramps are located.
Escape ramps save lives, equipment, and cargo. Use them if you lose your brakes.
Slippery Surfaces
It will take longer to stop and it will be harder to turn without skidding when the road is slippery.
You must drive slower to be able to stop in the same distance as on a dry road. Wet roads can
double stopping distance. On a wet road, you should reduce your speed by about one-third
(e.g., slow from 55 mph to about 35 mph). On packed snow, reduce speed by a half or more. If
the surface is icy, reduce speed to a crawl. If the road you are driving on becomes very slippery
due to glare ice, stop driving as soon as you can safely do so.
The following are some safety guidelines:
• Start gently and slowly – When first starting, get the feel of the road. Don’t hurry. If you
use too much power, the drive wheels may spin and you could lose control.
• Adjust turning and braking to 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 on slippery surfaces.)
• Adjust speed to conditions – Don’t pass slower vehicles unless necessary. Go slow
and watch far enough ahead to keep a steady speed. Avoid having to slow down and
speed up. Take curves at slower speeds and don’t brake while in curves. Be aware
that as the temperature rises to the point where ice begins to melt, the road becomes
even more slippery. Slow down more.
• Adjust space to conditions – Don’t drive alongside other vehicles. Keep a longer
following 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 slow down gradually.
• Wet brakes – When driving in heavy rain or deep standing water, your brakes will 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 power, wheel lockups, pulling to one side or the
other and jackknife if you pull a trailer.
• Avoid driving through deep puddles or flowing water if possible. If not, you should:
o Slow down.
o Place transmission in a low gear.
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o
o
o
o
Gently put on the brakes. This presses the linings against the brake drums or
discs and keeps mud, silt, sand, and water out of your brakes, keeping your
brakes working.
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 stop when safe to do so. Make sure no one is following, and then
apply the brakes to be sure they work right. If not, dry out further as described
above. (CAUTION: Do not apply too much brake pressure and accelerator at the
same time or you can overheat brake drums and linings.)
Identifying Slippery Surfaces
Sometimes it’s hard to know if the road is slippery. Here are some signs of slippery roads.
• Shady areas – Shady parts of the road will remain icy and slippery 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˚ F.
• Melting Ice – Slight melting will make ice wet. Wet ice is much more slippery than ice
that is not wet.
• Black Ice – Black ice is a thin layer that is clear enough that you can see the road
underneath it. It makes the road look wet. Any time the temperature is below 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 the front of
the mirror, mirror support, or antenna. If there’s ice on these, the road surface is
probably starting to ice up.
• Just after rain begins – Right after it starts to rain, the water mixes with oil left on the
road by vehicles. This makes the road very slippery. If the rain continues, it will wash
the oil away.
• Hydroplaning – In some weather, water or slush collects on the road. When this
happens, your vehicle can hydroplane. It’s like water skiing. The tires lose their
contact with the road and have little or no traction. You may not be able to steer or
brake. If the vehicle is hydroplaning, do not use the brakes to slow down, release the
accelerator. This will slow your vehicle and let the wheels turn freely. If the drive
wheels start to skid and you have a manual transmission, push in the clutch to let
them turn freely. It does not take a lot of water to cause hydroplaning. Hydroplaning
can occur at speeds as low as 30 mph if there is a lot of water. Hydroplaning is more
likely if tire pressure is low or the tread is worn. The grooves in a tire can carry water
away; if they aren’t deep, they won’t work. Be especially careful when driving through
puddles. The water is often deep enough to cause hydroplaning.
Steering
Keep Both Hands on the Steering Wheel
The proper way to hold a steering wheel is with both hands on opposite sides of the wheel. In
order to turn quickly, you must have a firm grip on the steering wheel. The best way to have
both hands on the wheel if there is an emergency is to keep them there all the time. If you do
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not have both hands on the wheel, the wheel could pull away from you if you hit a curb or a
pothole (chuckhole).
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 ahead. Remember, you can always turn
to miss an obstacle more quickly than you can stop. (However, top-heavy vehicles and tractors
with multiple trailers may flip over.)
Steering to Avoid a Crash
A quick turn can be made safely if it’s done the right 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 greater the chances of a skid or rollover.
• Be prepared to “counter steer,” that is, to turn the wheel back in the other direction,
once you’ve passed whatever was in your path. Unless you are prepared to counter
steer, you won’t be able to do it quickly enough. You should think of emergency
steering and counter steering as two parts of one driving action.
Where to Steer
If an oncoming driver drifts into your lane and is headed straight for you, steer to your right is
best action to take. If that driver realizes what has happened, the 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.
If you have been using your mirrors, you’ll know which lane is empty and can be safely used.
• If the shoulder is clear, going right may be best. No one is likely to be driving on the
shoulder but someone may be passing you on the left.
• If you are blocked on both sides, a move to the right may still be best. At least you
won’t force anyone into an opposing traffic lane and a possible head-on collision.
Leaving the Road
In some emergencies, you may have to drive off the road. It may be less risky than facing a
collision with another vehicle.
Most shoulders are strong enough to support the weight of a large vehicle and, therefore, offer
an available escape route. Here are some guidelines if you need to leave the road:
• Avoid Braking – If possible, avoid braking until your speed has dropped to about 20
mph. Then brake very gently to avoid skidding on a loose surface.
• Keep one set of wheels on pavement if possible – This helps to maintain control.
• 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 moving back onto the road when it is
safe.
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• Returning to the Road – If you are forced to return to the road before you can stop,
use the following procedure:
o Hold the wheel tightly and turn sharply enough to get right back on the road
safely.
o Don’t try to edge gradually back on the road. If you do, your tires might grab
unexpectedly and you could lose control.
When both front tires are on the paved surface, counter steer immediately. The two turns should
be made as a single “steer-counter-steer” move.
Backing a Trailer
When backing a car, straight truck, or bus, you turn the top of the steering wheel toward 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.
Because you cannot see everything behind your vehicle, backing up is always dangerous. Avoid
backing whenever you can. When you park, try to park so you will be able to pull forward when
you leave.
When you do have to back up with a trailer, try to position your vehicle so you can back in a
straight line. Additionally, here are a few simple safety rules:
Look at your path – Look at your line of travel before your begin. Get out and walk
around the vehicle. Check your clearance to the sides and overhead in and near the
path your vehicle will take.
Back slowly – Always back as slowly as possible. Use the lowest reverse gear. That way
you can easily correct any steering errors. You also can stop quickly if necessary.
Use the mirrors – The mirrors will help you see whether the trailer is drifting to one side
or the other.
Correct drift immediately – As soon as you see the trailer getting off course, correct it by
turning the top of the steering wheel in the direction of the drift.
Use driver-side backing – Back and turn toward the driver’s side whenever possible
especially on a curved path. Back to the driver’s side so you can see well. Backing
toward the right side is very dangerous because you can’t see as well. If you back and
turn toward the driver’s side, you can watch the rear of your vehicle by looking out the
side window. Use driver-side backing even if it means going around the block to put your
vehicle in this position. The added safety is worth it.
Pull forward – When backing a trailer, make pull-ups to reposition your vehicle as
needed.
Use a helper – If possible, a helper should be used whenever you have to back your
vehicle. There are blind spots you can’t see. The helper should stand near the back of
your vehicle where you can see them. Before you begin backing, work out a set of hand
signals that you both understand. Agree on a signal for “STOP.”
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Braking
If somebody suddenly 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 correctly.
You can use the “controlled braking” or the “stab braking” method to keep a vehicle in a straight
line when braking. This will then allow you to turn if it becomes necessary.
Controlled braking
With this method, you apply the brakes as hard as you can without locking the wheels.
• Keep steering wheel movements very small while doing this.
• If you need to make a larger steering adjustment or if the wheels lock, release brakes.
• Reapply the brakes as soon as you can.
Stab 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 can take up to one
second for the wheels to start rolling after you release brakes. If you reapply the
brakes before the wheels start rolling, the vehicle won’t straighten out.)
Emergency braking does not mean pushing down on the brake pedal as hard as you can. That
will only keep the wheels locked up and cause a skid. If the wheels are skidding, you cannot
control the vehicle.
Retarders
Some vehicles have “retarders.” Retarders help slow a vehicle, reducing the need for using your
brakes. They reduce brake wear and give you another way to slow down. There are many types
of retarders (exhaust, engine, hydraulic, electric). All retarders can be turned on or off by the
driver. On some, the retarder power can be adjusted. When turned “on,” the retarders apply
their braking power, to the drive wheels only, whenever you let up on the accelerator pedal all
the way.
Caution: Retarders can cause the drive wheels to skid when the drive wheels have
poor traction. Therefore, you should turn the retarder off whenever the road is wet, icy,
or snow covered.
Brake Failure
Brakes kept in good condition rarely fail. (Air brakes are discussed in Section 3) Most hydraulic
brake failures occur for one of three reasons:
• Loss of hydraulic pressure.
• Brake fade on long hills.
• Brake fade due to being out of adjustment.
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Loss of Hydraulic Pressure
When the system won’t build up pressure, the brake pedal will feel spongy or go to the floor.
Here are some things you can do:
1. Downshift – Putting the vehicle into a lower gear will help to slow the vehicle.
2. Pump the brakes – Sometimes pumping of the brake pedal will generate enough
hydraulic pressure to stop the vehicle.
3. Use the parking brake – The parking or emergency brake is separate from the hydraulic
brake system. Therefore, it can be used to slow the vehicle. However, be sure to press
the release button or pull the release lever at the same time you use the emergency
brake so you can adjust the brake pressure and keep the wheels from locking up.
4. Find an escape route – While slowing the vehicle, look for an escape route (an open
field, side-street or escape ramp). Turning uphill is a good way to slow and stop the
vehicle. Make sure the vehicle does not start rolling backward after you stop. Put it in low
gear, apply the parking brake, and if necessary, roll back into some obstacle that will
stop the vehicle.
5. Brake failure on Downgrades – Going slow enough and braking properly will almost
always prevent brake failure on long down-grades. Once the brakes have failed,
however, you will need to look outside your vehicle for something to stop it.
• Your best hope is an escape ramp. If there is one, there’ll be signs telling you
about it. Use it. Ramps are usually located a few miles from the top of the
downgrade. Every year, hundreds of drivers avoid injury or damage to their
vehicles by using escape ramps. Some escape ramps use soft gravel that resists
the motion of the vehicle and brings it to a stop. Others turn uphill, using the hill to
stop the vehicle and soft gravel to hold it in place.
• 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
worse.
• If no escape ramp is available, take the least hazardous escape route you can –
such as an open field or a side road that flattens out or turns uphill. Make the move
as soon as you know your brakes don’t work. The longer you wait, the faster the
vehicle will go and the harder it will be to stop.
Brake Fading on Long Hills
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 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. To prevent brake fade, you should select a gear which will keep your
vehicle to a safe speed on steep downgrades.
Brake Fade Due to Being Out of Adjustment
Brakes also can fade because of being out of adjustment. To safely control a vehicle, every
brake must do its share of the work. If some brakes are out of adjustment, they will not be doing
their share. The other brakes can overheat and fade and there will not be enough braking
available to control the vehicle. Brakes can get out of adjustment when they are used a lot and
should be checked often. Also, brake linings wear faster when they are hot.
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Proper Braking Technique
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 proper low gear, the following is a proper
braking technique:
™ Apply the brakes just hard enough to feel a definite slowdown.
™ When your speed has been reduced to approximately 5 mph below your “safe” speed,
release the brakes. [This brake application should last for about three (3) seconds.]
™ When your speed has increased to your “safe” speed, repeat the steps above. For
example: if your “safe” speed is 40 mph, you now apply the brakes hard enough to
gradually reduce your speed to 35 mph and then release the brakes. Repeat this as
often as necessary until you have reached the end of the downgrade.
Be Aware of Your Surroundings
To be a safe driver, you need to know what’s going on all around your vehicle. Not using your
eyes properly is a major cause of accidents.
Looking 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 lot of distance, knowing what the traffic is doing on all sides is very important.
You need to look well enough ahead to make sure you have room to make these
moves safely.
• How far ahead to look – A driver should look 12 to 15 seconds ahead of the vehicle
while driving. 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 to stop too quickly
or make lane changes. Looking 12 to 15 seconds ahead doesn’t mean not paying
attention to things that are closer to you. Good drivers shift their attention back and
forth, near and far.
• 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.
• Look for road conditions – Look for hills and curves, or anything that may require you
to reduce your speed. Pay attention to traffic signals and signs. If a light has been
green for some time, anticipate the change, start slowing down, and be ready to stop.
Traffic signs may alert you to road conditions where you may have to change speed.
Use Your Mirrors
It’s important to know what is going on behind and to the sides of your vehicle. You should
adjust your mirrors prior to starting a trip. Check your mirrors regularly and check more often in
special situations. However, remember there are “blind spots” that your mirrors cannot show
you.
• Traffic – Check the mirrors for vehicles on either side and in back of you. In an
emergency, you may need to know if you can make a quick lane change.
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• 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 can 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.
o Lane changes – You need to check your mirror to make sure no one is along
side you or about to pass you. If you saw a car approaching from the rear, then
the next time you check your mirror you do not see the car, you should wait to
change lanes until you are sure the car isn’t in your blind spot. Check your
mirrors:
ƒ Before you change lanes to make sure there’s enough room;
ƒ After you have signaled, to check that no one has moved from your blind
spot;
ƒ Right after you start the lane change to double-check that your path is
clear; and
ƒ After you complete the lane change.
o Turns – Use your mirrors to check where the rear of your vehicle is while you
make turns. This will help make sure you don’t hit anything.
o Merges – Use your mirrors to make sure the gap in traffic is large enough for you
to enter safely.
o Tight maneuvers – Any time you are driving in close quarters, use your mirrors
often to make sure you have enough clearance.
• How to use mirrors – Use mirrors correctly by checking them quickly and
understanding what you use.
o Checking quickly – 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 ahead.
o Understanding what you see – Many large vehicles have curved (convex,
“fisheye,” “spot,” “bugeye”) mirrors that show a wider area than flat mirrors. This
is often helpful. But everything appears smaller in a convex mirror that 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.
Signal Your Intentions
Other driver’s can’t know what you are going to do until you tell them. Signaling what you intend
to do is important for safety, and it’s the law. Here are some general rules for signaling.
Turns – There are three good rules for using turn signals:
1. Signal early. Signal well before you turn. It’s the best way to keep others from
trying to pass you.
2. Signal continuously. You need both hands on the wheel to turn safely. Don’t
cancel the signal until you have completed the turn.
3. Cancel your signal. Don’t forget to turn off your turn signal after you’ve turned if
you don’t have self-cancelling signals.
Lane changes – Signal early and change lanes slowly and smoothly. This will allow a driver
you didn’t see to honk the horn and/or avoid your vehicle.
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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 4-way emergency flashers when you are driving very slow 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 slow you have to go to make a tight turn
in a large vehicle. Warn drivers behind you by braking early and slowing gradually.
• Stopping on the road – Truck and bus drivers sometimes stop in the road to unload
cargo or passengers or stop 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 slowly, 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 for each state where you will be
driving.)
• 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.
Communicate Your Presence
Other drivers may not notice your vehicle even when it’s in plain sight. Let them know you’re
there to help prevent accidents.
• 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. At night, flash your lights from low to high beam and back.
Don’t leave your high beams on until you have completely passed the vehicle. Drive
carefully enough to avoid a crash even if they don’t see or hear you.
• When it’s hard to see – At dawn or dusk, or in rain or snow, it can be hard to see and
be seen. If you are having trouble seeing other vehicles, other drivers will have trouble
seeing you. You can let others know you are there by turning on the low beam
headlights, not just the identification or clearance lights.
• When parked at the side of the road – When you pull off the road and stop, always be
sure to turn on the 4-way emergency flashers. This is especially important at night.
Don’t trust the taillights to give warning. Drivers have crashed into the rear of a parked
vehicle because they thought it was moving normally.
If you must stop on the road or the shoulder of a road, you should put out your reflective
triangles within ten minutes. Warning devices must always be carried in your vehicle. Place your
warning devices at the following locations:
• On the traffic side of the vehicle, within ten (10) feet of the front or rear corners to
mark the location of the vehicle. (Fig. 1-1)
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Figure 1-1
Warning Device Placement:
Two-Lane (traffic in both directions) or
Undivided Highway
• Approximately
100
feet
behind and ahead of the
vehicle on the shoulder or in
the lane you are stopped in.
(Fig. 1-1)
• If a hill or curve keeps oncoming drivers from seeing
the vehicle within 500 feet,
move the rear reflective
triangle back down the road. (Fig 1-2)
Figure 1-2
Warning Device Placement:
Obstructed View
• If you must stop on or by a one-way divided highway, place warning devices 10 feet,
100 feet, and 200 feet toward the approaching traffic. (Fig. 1-3)
Figure 1-3
Warning Device Placement:
One-Way or Divided Highway
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• When putting out the triangles, hold them between yourself and the oncoming traffic
for your own safety and so other drivers can see you.
Use your horn when needed
Your horn can let others know you are 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.
Managing Space
To be a safe driver, you need space all around your vehicle. When things go wrong, space
gives you time to think and to take action. To have space available when something goes
wrong, you need to manage your space. While this is true for all drivers, it is especially
important for large vehicles. They take up more space and require more space for stopping and
turning.
Space ahead
Of all of the space around your vehicle it is the area ahead of the vehicle, the space you are
driving into, that is most important. You need space ahead in case you must suddenly stop.
According to accident reports, the vehicle that trucks and buses most often run into is the one in
front of them. The most frequent cause is following too closely. Remember, if the vehicle ahead
of you is smaller than yours, it can probably stop faster than you can. You may crash if you are
following too closely.
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 one second for safety. For example, if you are driving a 40-foot vehicle at 35 mph and the
road is dry and visibility is good, you should leave 4 seconds between you and the vehicle
ahead. In a 60-foot rig, you will need 6 seconds. Over 40 mph, you would need 5 seconds for a
40-foot vehicle and 7 seconds for a 60-foot vehicle.
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 10 feet of length. 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 one second for
speeds above 40 mph. Also remember that when the road is slippery, you need much more
space to stop.
Space behind
You can’t stop others from following you too closely, but there are things you can do to make it
safer:
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• Stay to the right; and
• Deal with tailgaters safely.
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
In a large vehicle, it’s often hard to see whether a vehicle is close behind you. When you are
traveling slowly, drivers trapped behind often follow closely. Also, many car drivers follow large
vehicles closely 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
crash:
• Avoid quick changes. If you have to slow down or turn, signal to reduce the chances of
a crash.
• 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.
• Don’t speed up. It’s safer to be tailgated at a low speed than a high speed.
• Don’t flash your brake lights or turn on your tail lights. Follow the suggestions above.
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.
Traveling next to others – There are two dangers in traveling alongside other vehicles:
• Another driver may change lanes suddenly and turn into you; and
• You may be trapped when you need to change lanes.
Strong winds – Strong winds make it difficult to stay in your lane. The problem is usually
worse for lighter vehicles and a double with empty trailers will have the most difficulty
staying in its lane. Winds are especially a problem when coming out of tunnels. Don’t
drive alongside others if you can avoid it.
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 vehicles, 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.
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Space overhead
Hitting overhead objects is a danger. Make sure you always have overhead clearance.
• Don’t assume that the height posted at bridges and overpasses are correct. Repaved
roads or packed snow may have reduced the clearances since the heights were
posted.
• The weight of a vehicle changes its height. An empty van is higher than a loaded one.
Going 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 may or may not be posted on low
bridges or underpasses.
• Some roads can cause a vehicle to tilt. There can be a problem clearing objects along
the edge of the road, such as signs or trees. Where this is a problem, drive a little
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. It’s easy to miss seeing them while you are backing.
(Also check for other hazards at the same time.)
Many drivers forget about the space under their vehicles. That space can be very small when a
vehicle is heavily loaded. Railroad tracks can stick up several inches. This is often a problem
on dirt roads and in unpaved yards where the surface around the tracks can wear away. Don’t
take a chance on getting hung up halfway across. Drainage channels across roads can cause
the end of some vehicles to drag. Cross such depressions carefully.
The space around a truck or bus is important in turns. Because of wide turning and off tracking,
large vehicles can hit other vehicles or objects during turns.
Right turns
Here are some rules to help prevent right-turn 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. See Figure 1-4,
page 23.
• Don’t turn wide to the left as you start the turn. A 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 turn. See Figure 1-5, page 23.
• If you must cross into oncoming traffic to make a turn, watch out for vehicles coming
toward you. Give them room to go by or stop. However, don’t back up for them
because you might hit someone behind you.
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Figure 1-4
Do This
Figure 1-5
Don’t Do This
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 of your vehicle may hit
another vehicle because of off-tracking.
If there are two turning lanes, always take the right-hand
turn lane. Don’t start in the inside lane, because you
may have to swing right to make the turn. Drivers on
your right may be hard for you to see. You may crash
into them.
Figure 1-6
If there are two left-turn lanes, use
the right-hand lane.
Space needed to cross or enter traffic
Be aware of the size and weight of your vehicle when you cross or enter traffic. Here are some
important things to keep in mind:
• Because of slow acceleration and the space large, heavy vehicles require, you may
need a much larger gap to enter traffic than you would in a car.
• Acceleration varies with the load. Allow more room if your vehicle is heavily loaded.
• Before you start across a road, make sure you can get all the way across before traffic
reaches you.
TEST YOUR KNOWLEDGE
1.
2.
3.
4.
How do you find out how many seconds of following distance space you have?
If you are driving a 30-foot vehicle at 55 mph, how many seconds of following distance
should you allow?
You should decrease your following distance if somebody is following you too closely.
True or False?
If you swing wide to the left before turning right, another driver may try to pass you on the
right. True or False?
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Driving at Night
You are at greater risk when you drive at night. Drivers can’t see hazards as easily as in
daylight, so they have less time to respond. Drivers caught by surprise are less able to avoid a
crash. The problems of night driving involve the driver, the roadway, and the vehicle. We will
discuss each of these factors.
Driver Factors
Vision, glare, fatigue and lack of alertness are all factors that need to be considered when
driving at night.
• Vision – People can’t see as sharply at night or in dim light. Also, the eyes need time
to adjust to seeing in dim light. Most people have noticed this when walking from
daylight into a dark room.
• Glare – Glare from your headlights can cause problems for drivers coming toward you.
They can also bother drivers going in the same direction you are when your lights
shine in their rearview mirror. Older drivers are especially bothered by glare. Most
people have been temporarily blinded by camera flash units or by the high beams of
an oncoming vehicle. It can take several seconds to recover from glare. Even two
seconds of glare blindness can be dangerous. A vehicle going 55 mph will travel more
than half the distance of a football field during that time. Don’t look directly at bright
lights when driving. Look at the right lane or edge marking if possible. Dim your lights
within 500 feet of an oncoming vehicle and when following another vehicle within 300
feet. If other drivers don’t put their low beams on, don’t try to “get back at them” by
switching to your high beams. This increases glare for oncoming drivers and increases
the chance of a crash.
• Fatigue and lack of alertness – Fatigue (being tired) and lack of alertness are bigger
problems at night. The body’s need for sleep is beyond a person’s control. Most
people are less alert at night, especially after midnight. This is particularly true if you
have been driving for a long time. A fatigued driver may not see hazards as soon or
react as quickly, so the chance of a crash is greater. If you are sleepy, the only safe
cure is to get off the road and get some sleep. If you don’t, you risk your life and the
lives of others.
Roadway Factors
Roadway factors such as lighting and other drivers are more apparent when driving at night.
• Poor lighting – In the daytime, there is usually enough light to see well. This is not true
at night. Some areas may have bright streetlights, but many areas will have poor
lighting. On most roads, you will probably have to depend entirely on your headlights.
Less light means you will not be able to see hazards as well as in daytime. Many
accidents at night involve pedestrians, bicyclists, and animals that are difficult to see in
low light. Even with street lights, traffic signals and hazards can be hard to see against
a background of signs, shop windows, and other lights. Drive slower when lighting is
poor or confusing. Drive slowly enough to be sure you can stop in the distance you
can see ahead. If you cannot see well with your headlights, use your high beams
when legal and keep your interior light off.
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• Drunk Drivers – Drunk drivers and drivers under the influence of drugs are a hazard to
themselves and to you. Be especially alert around the closing times for bars and
taverns. Watch for drivers who have trouble staying in their lane or maintaining speed,
stop without reason, or show other signs of being under the influence of alcohol or
drugs.
Vehicle Factors
• Headlights – At night, your headlights will usually be the main source of light for you to
see and for others to see you. You can’t see nearly as much with your headlights as
you can during the daytime. With low beams, you can see ahead about 250 feet and
with high beams about 350-500 feet. You must adjust your speed to keep your
stopping distance within your sight distance. This means going slow enough to be able
to stop within the range of your headlights. Otherwise, by the time you see a hazard,
you will not have time to stop. Use high beams when it is safe and legal to do so. Use
them when you are not within 500 feet of an approaching vehicle. Also, don’t let the
inside of your vehicle get too bright. This makes it harder to see outside. Keep the
interior light off and adjust your instrument lights as low as you can and still read the
gauges. Night driving can be more dangerous if you have problems with your
headlights. Dirty headlights may give only half the light they should, cutting down your
visibility and making it harder for others to see you. Make sure your lights are clean
and working. Have a qualified person make sure they are adjusted properly.
Headlights that are out of adjustment will not provide the directional light intended and
may be directed inappropriately at other drivers.
• Other Lights – In order for you to be seen easily, your reflectors, marker lights,
clearance lights, taillights, and identification lights must be clean and working properly.
• Turn Signals and Brake Lights – At night, your turn signals and brake lights are even
more important for telling other drivers what you intend to do. Make sure you have
clean, working turn signals and stop lights.
• Windshields and Mirrors – It is more important at night than in the daytime to have a
clean windshield and mirrors. Bright lights at night can cause dirt on your windshield or
mirrors to create a glare of its own, blocking your view. Most 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 the windshield that seemed to look okay in the middle of the day.
Clean your windshield on the inside and outside for safe driving.
Driving in Winter
Make sure your vehicle is ready for driving in winter weather. You should make a regular pre-trip
inspection, paying extra attention to the following items:
•
•
•
Coolant and Antifreeze Levels – Make sure the cooling system is full and there is
enough anti-freeze in the system to protect against freezing. This can be checked with a
special coolant tester.
Defrosting and Heating Equipment – Make sure the defrosters work. They are needed
for safe driving. Check that the heater is working properly before starting your trip and
that you know how to operate 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 the windshield hard enough to wipe the
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•
•
•
•
•
•
window clean. Otherwise they may not sweep off snow properly. Make sure the
windshield washer works and there is washing fluid contained in the washer reservoir.
Use windshield washer antifreeze to prevent freezing of the washer liquid. If you can’t
see well enough while driving, stop safely and fix the problem.
Tires – Make sure you have enough tread on your tires. The drive tires must provide
traction 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 should have at least 4/32 inch tread depth in every major groove on front
wheels and at least 2/32 inch on other wheels. More would be 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 chains,
even to get to a place of safety. Carry the right number of chains and extra cross links.
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. Learn how to put the chains on
before you need to do it.
Lights and Reflectors – Make sure the lights and reflectors are clean. Lights and
reflectors are especially important during bad weather. Check from time to time during
bad weather to make sure they are clean and working right.
Hand Holds, Steps and Deck Plates – Remove all ice and snow from hand holds, steps
and deck plates which you must use to enter the cab or to move about the vehicle. This
will reduce the danger of slipping.
Radiator Shutters and Winter Front – Remove ice from the radiator shutters. Make sure
the winter front is not closed too tightly. If the shutters freeze shut or the winter front is
closed too much, the engine may overheat and stop.
Exhaust System – Exhaust system leaks are especially dangerous when cab ventilation
may be poor (windows rolled up, etc.) Loose connections could permit poisonous carbon
monoxide to lead into your vehicle. Carbon monoxide gas will cause you to be sleepy.
Large amounts of carbon monoxide can kill you. Check the exhaust system for loose
parts and for sounds and signs of leaks.
Driving in Very Hot Weather
Do a normal pre-trip inspection by paying special attention to the following items:
•
•
•
Tires – Check the tire mounting and air pressure. Inspect the tires every two hours or
every 100 miles 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 cool off. If a
tire is too hot to touch, remain stopped until the tire cools off. Otherwise, the tire may
blow out or catch fire. Pay special attention to recapped or re-treaded tires. Under high
temperatures the tread may separate from the body of the tire.
Engine oil – The engine oil helps keep the engine cool, as well as lubricating it. Make
sure there is enough engine oil. If you have an oil temperature gauge, make sure the
temperature is within the proper range while you are driving.
Engine coolant – Before starting out, make sure the engine cooling system has enough
water and antifreeze according to the engine manufacturer’s directions. (Antifreeze helps
the engine under hot conditions as well as cold conditions.) When driving, check the
water temperature or coolant temperature gauge from time to time. Make sure that it
remains in the normal 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.
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Some vehicles have sight glasses or see-through coolant overflow containers or coolant
recovery containers. These permit you to check the coolant level while 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. If the engine is
overheating, never remove the radiator cap or any part of the pressurized system until
the system has cooled. Steam and boiling water can spray under pressure and cause
severe burns. If you can touch the radiator cap with your bare hand, it is probably cool
enough to open.
If coolant has to be added to a system without a recovery tank or overflow tank, follow
these steps:
™
™
™
™
™
™
Shut engine off.
Wait until engine has cooled.
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 from cooling system.
When all pressure has been released, press down on the cap and turn it further
to remove it.
™ Visually check level of coolant and add more coolant if necessary.
™ Replace cap and turn all the way to the closed position.
• Engine belts – Learn how to check V-belt tightness on your vehicle by pressing on the
belts. Loose belts will not turn the water pump and/or fan properly. This will result in
overheating. Also check belts for cracking or other signs of wear.
• Hoses – Make sure coolant hoses are in good condition. A broken hose while driving can
lead to engine failure and fire.
• Watch for bleeding tar – Tar in the road pavement frequently rises to the surface in very
hot weather. Spots where tar “bleeds” to the surface are very slippery.
• Go slow enough to prevent overheating – High speeds create more heat for tires and
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 fire and engine failure.
TEST YOUR KNOWLEDGE
1.
2.
3.
4.
5.
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 False?
You can safely remove the radiator cap as long as the engine isn’t overheated.
True or False?
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Seeing Hazards
Importance of Seeing Hazards
• What is a Hazard? A hazard is defined as an unavoidable danger or risk (such as
another driver, bicyclist, pedestrian, or road debris). Tourists can be hazards because
they may drive slowly and make sudden stops or lane changes.
• Seeing Hazards Lets You Be Prepared – You will have more time to act if you see
hazards before they become emergencies. In the example above, you might make a
lane change or slow down to prevent a crash if the car suddenly cuts in front of you.
Seeing this hazard gives you time to check your mirror and signal a lane change.
Being prepared reduces the danger. A driver who did not see the hazard until the slow
car pulled back on the highway in front of him would have to do something very
suddenly.
• Learning to See Hazards – There are often clues that will help you see hazards. The
more you drive, the better you can get at seeing hazards. This section will talk about
hazards that you should be aware of.
Hazardous Roads
Slow down and be very careful if you see any of the following road hazards:
• Work Zones – Construction zones on the highway could be considered a potential
hazard. You may encounter narrowed lanes, obstacles, and uneven surfaces. Drive
slowly and carefully through work zones and watch for sharp pavement drop-offs. Use
your 4-way flashers or brake lights to warn drivers behind you when appropriate.
• Uneven Road Shoulder – Pavement may drop near the edge of the road. Steering
may be difficult if you drive off the edge of the road and are forced to take corrective
action. Driving too close to the edge may also cause your vehicle to tilt, making the top
of your trailer hit roadside objects such as tree limbs or signs.
• Road Debris – Things that have fallen onto the road could cause damage to your tires
and wheel rims. Debris can harm electrical and brake lines, or if caught between dual
tires, could cause severe damage. It is important to remain alert for objects of all sorts,
so you can see them early enough to take the appropriate action.
• Off ramps/On ramps – Freeway and turnpike exits can be particularly dangerous for
commercial vehicles. Off ramps and on ramps often have speed limit signs posted.
Remember, these speeds may be safe for automobiles but may not be safe for larger
vehicles or heavily loaded vehicles. Exits that go downhill and turn at the same time
can be especially dangerous. You should slow down to a safe speed before the curve.
The downgrade makes it difficult to reduce speed, and braking and turning at the
same time can be a dangerous practice.
Drivers Who Are Hazards
In order to protect yourself and others, you must know when other drivers may do something
hazardous. Some clues to this type of hazard are discussed below.
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Blocked Vision
People who can’t see others are a very dangerous hazard. Be alert of drivers whose vision is
blocked. Vans, loaded station wagons, and cars with the rear window blocked are examples.
Rental trucks should be watched carefully. Their drivers are often not used to the limited vision
to the sides and rear of the truck. In winter, vehicles with frosted, ice covered, or snow covered
windows are also hazards.
Vehicles may be partly hidden by blind intersections or alleys
If you only can see the rear or front end of a vehicle but not the driver, then he or she can’t see
you. Be alert because he/she may back out of an alley into your lane. Always be prepared to
stop.
Delivery trucks can present a hazard
Packages or vehicle doors often block the driver’s vision. Drivers of step vans, postal vehicles,
and local delivery vehicles often are in a hurry and may suddenly step out of their vehicle into
the traffic lane.
Parked vehicles can be hazards
When vehicles are parked, people may start to get out, or they may suddenly start up and drive
into your way. Watch for movement inside the vehicle itself that shows people are inside. Watch
brake lights or backup lights, exhaust, and other clues that a driver is about to move.
Be careful of a stopped bus
Passengers may cross in front of, or behind, the bus and they often can’t see you.
Pedestrians and bicyclist can also be hazards
Walkers, joggers, and bicyclists may be on the road with their back to the traffic, so they can’t
see you. Sometimes they wear portable stereos with head sets, so they can’t hear you, either.
This can be dangerous. On rainy days, pedestrians may not see you because of hats or
umbrellas. They may be hurrying to get out of the rain and may not pay attention to the traffic.
Emergencies
Traffic emergencies occur when two vehicles are about to collide. Vehicle emergencies occur
when tires, brakes, or other critical parts fail. Following the safety practices in this manual can
help prevent emergencies. But, if an emergency does happen, your chances of avoiding a crash
depend upon how well you take action. Actions you can take are discussed below.
Tire Failure
There are four important things that safe drivers do to handle a tire failure safely:
• Be aware that a tire has failed.
• Hold the steering wheel firmly.
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• Stay off the brake.
• After stopping, check all the tires.
Recognize Tire Failure
Quickly knowing you have a tire failure will let you have more time to react. Having just a few
seconds to remember what you’re supposed to do can help you. The major signs of tire failure
are:
Sound – The loud “bang” of a blowout is an easily recognized sign. Because it can 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 was yours.
Vibration – If the vehicle thumps or vibrates heavily, it may be a sign that one of the tires
has gone flat. 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 of a rear tire will cause the vehicle to slide back and forth or
“fishtail.” However, dual rear tires usually prevent this.
Any of these signs is a warning of possible tire failure. You should do the following:
Hold the Steering Wheel Firmly – If a front tire fails, it can twist the steering wheel out of
your hand. The only way to prevent this is to keep a firm grip on the steering wheel with
both hands at all times.
Stay Off the Brake – It’s natural to want to brake in an emergency. However, braking
when a tire has failed could cause loss of control. Unless you’re about to run into
something, stay off the brake until the vehicle has slowed down. Then brake very gently,
pull off the road, and stop.
Check the Tires – After you’ve come to a stop, get out and check all the tires. Do this
even if the vehicle seems to be handling all right. If one of your dual tires goes flat, the
only way you may know it is by getting out and looking at it.
Skid Control and Recovery
A skid happens whenever the tires lose their grip on the road. This is caused in one of four
ways:
Over braking – Braking too hard (over braking) will lock up the wheels. Skids also can
occur when using the speed retarder when the road is slippery.
Over steering – Turning more sharply than the vehicle can safely turn.
Over acceleration – Supplying too much power to the drive wheels, causing them to
spin.
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Driving too fast – Most serious skids result from driving too fast for road conditions.
Drivers who adjust their driving to conditions don’t over accelerate and don’t have to
over brake or over steer from too much speed.
Drive-Wheel Skids
By far, the most common skid is one in which the rear wheels lose traction through excessive
braking or acceleration. Skids caused by acceleration usually happen on ice or snow. Taking
your foot off the accelerator can easily stop them. (If it is very slippery, push the clutch in.
Otherwise the engine can keep the wheels from rolling freely and regaining traction.)
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.
Correcting a Drive-Wheel Braking Skid
Do the following to correct a drive-wheel braking skid:
Stop braking – This will let the rear wheels roll again and keep the rear wheels from
sliding any further. If on ice, push in the clutch to let the wheels turn freely.
Turn quickly – When a vehicle begins to slide sideways, quickly steer in the direction you
want the vehicle to go – down the road. You must turn the wheel quickly.
Counter steer – As a vehicle turns back on course, it has a tendency to keep right 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
counter steer in a skid takes a lot of practice. The best place to get this practice is on a
large driving range or “skid pad.”
Front-Wheel Skids
Most front-wheel skids are caused by driving too fast for conditions. Other causes are
lack of tread on the front tires and cargo loaded so not enough weight is on the front
axle. 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-wheel 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 possible without
skidding.
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TEST YOUR KNOWLEDGE
1.
2.
3.
4.
Stopping is not always the safest thing to do in an emergency. True or False
What are some advantages of going right instead of left around an obstacle?
What is an “escape ramp”?
If a tire blows out, you should put the brakes on hard to stop quickly. True or False?
Accident Procedures
When you’re in an accident and not seriously hurt, you need to act to prevent further damage or
injury. The basic steps to be taken at any accident are to:
Protect the Area
The first thing to do at an accident scene is to keep another accident from happening at the
same spot. To protect the accident area:
• If your vehicle is involved in the accident, try to get it to the side of the road. This will
help prevent another accident and allow traffic to move.
• If you’re stopping to help, park away from the accident. The area immediately around
the accident will be needed for emergency vehicles.
• Put on your flashers.
• Set out reflective triangles to warn other traffic. Make sure they can be seen by other
drivers in time for them to avoid the accident.
Notify Authorities
If you have a CB, put out a call over the emergency channel, or if you have a cell phone, dial 91-1 before you get out of 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.
Care for Injured
If a qualified person is at the accident and helping the injured, stay out of the way unless asked
to assist. Otherwise, do the best you can to help any injured parties. Here are some simple
steps to follow in giving assistance:
• Don’t move a severely injured person unless the danger of fire or passing traffic
makes it necessary.
• Stop heavy bleeding by applying direct pressure to the wound.
• Keep the injured person warm.
Fires
Truck fires can cause damage and injury. Learn the cause of fires and how to prevent them.
Know what to do to extinguish fires.
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Causes of Fire – The following are some causes of vehicle 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, loose connections.
Fuel – Driver smoking, improper fueling, loose fuel connections.
Cargo – Flammable cargo, improperly sealed or loaded, poor ventilation.
Fire Prevention - Pay attention to the following:
• Pre-trip inspection – Make a complete inspection of the electrical, fuel, and exhaust
systems, tires and cargo.
• En-route inspection – Check the tires, wheels, and truck body for signs of heat
whenever you stop during a trip.
• Follow safe procedures – Follow correct safety procedures for fueling the vehicle,
using brakes, handling flares, and other activities that can cause a fire.
• Monitoring – Check the instruments and gauges often for signals of overheating, and
use the mirrors to look for signs of smoke from the tires or the vehicle.
• Caution – Use normal caution in handling anything flammable.
Fire Fighting
Knowing how to fight fires is important. Fires have been made worse by drivers who didn’t know
what to do. Here are some procedures to follow in case of fires:
• Pull off the road – The first step is to get the vehicle off the road and stop. In doing so:
o Park in an open area, away from buildings, trees, brush, other vehicles or
anything that might catch fire.
o Don’t pull into a service station!
o Use your CB radio if you have one to notify the police of your problem and your
location; or
o If you have a cell phone, dial 9-1-1 for assistance.
• Keep the fire from spreading – Before trying to put out the fire, make sure that it
doesn’t spread any further.
o With an engine fire, turn off the engine as soon as you can. Don’t open the hood
if you can avoid it. Shoot extinguishers through louvers, radiator, or from the
underside of the vehicle.
o For a cargo fire in a van or box trailer, keep the door shut, especially if your cargo
contains hazardous materials. Opening the van doors will supply the fire with
oxygen and can cause it to burn very fast.
• Use the right fire extinguisher
o The B:C type fire extinguisher is designed to work on electrical fires and burning
liquids.
o The A:B:C type is designed to work on burning wood, paper or cloth, but don’t
use water on an electrical fire (you could get shocked) or a gasoline fire (it will
spread the flames).
o A burning tire must be cooled. Lots of water may be required. If you’re not sure
what to use, especially on a hazardous materials fire, wait for qualified fire
fighters.
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• Extinguishing the fire – Here are some rules to follow in putting out a fire:
o Know how the fire extinguisher works before a fire happens. Study the
instructions printed on the extinguisher before you need it.
o When using the extinguisher, stay as far away from the fire as possible.
o Aim at the source or base of the fire, not up in the flames. Position yourself
upwind. Let the wind carry the extinguisher to the fire rather than carrying the
flames to you.
o Continue until whatever was burning has been cooled. Absence of smoke or
flame does not mean the fire is completely out or cannot restart.
o Only try to extinguish a fire if you know what you are doing and it is safe to do so.
TEST YOUR KNOWLEDGE
1.
2.
3.
4.
5.
What are some things to do at an accident scene to prevent another accident?
Name two causes of tire fires.
What kinds of fires is a B:C extinguisher not good for?
When using your extinguisher, should you get as close as possible to the fire?
Name some causes of vehicle fires.
Staying Alert and Fit to 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 can do to help stay alert and safe. Here are a few
suggestions:
Get enough sleep
Leaving on a long trip when you are already tired is dangerous. If you have a long trip
scheduled, make sure you get good sleep before you go. Most people require 7 to 8 hours of
sleep every 24 hours.
Schedule trips safely
Your body gets used to sleeping during certain hours of a day. 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 motor vehicle accidents occur between midnight and 6 a.m. Tired drivers
can easily fall asleep at these times, especially if they don’t regularly drive at those hours.
Trying to push on and finish a long trip at these times can be very dangerous.
Avoid medication
Many medicines can make you drowsy. Those medicines have label warnings against operating
vehicles or machinery. The most common is an ordinary cold pill. If you have to drive with a
cold, you are better off suffering from the cold symptoms than from the effects of the medicine.
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Keep cool
A hot, poorly ventilated cab can make you sleepy. Keep the window or vent cracked, or use the
air conditioner if you have one.
Take breaks
Short breaks can help you stay alert, but the time to take them is before you are drowsy. Stop
often. Walk around and inspect your vehicle. It may help to do some physical exercise.
When You do Become 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 rules to follow:
• Stop to sleep – When you body needs sleep, sleep is the only thing that will work. If you
have to make a stop anyway, make it whenever you feel the first signs of sleepiness, even
if it is earlier than you planned. By getting up a little earlier the next day, you can keep on
schedule without the danger of driving while you are not alert.
• Take a nap – If you can’t stop for the night, at least pull off the road and take a nap. A halfhour nap will do more to overcome fatigue than a half-hour coffee stop.
• Avoid drugs – There are no drugs that can overcome being tired. While they may keep you
awake for a while, they won’t make you alert. And eventually, you’ll be even more tired than
if you hadn’t taken them at all. Sleep is the only thing that can overcome fatigue.
Alcohol and Driving
Drinking alcohol and then driving is a very serious problem. People who drink alcohol are
involved in traffic accidents resulting in over 20,000 deaths every year. You should know:
•
•
•
•
How alcohol works in the human body
How it affects driving
Laws regarding drinking and driving
Legal, financial, and safety risks of drinking and driving
The truth about alcohol
There are many dangerous ideas about the use of alcohol. The driver who believes in these
wrong ideas will be more likely to get into trouble. Here are some examples:
False
True
Alcohol increases the ability to drive.
Alcohol is a drug that will make you
less alert and reduce your ability to
drive safely.
Some people can drink a lot and not
seem affected by it.
Everyone who drinks is affected by
alcohol.
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If you eat a lot first, you won’t get
drunk.
Food will not keep you from getting
drunk.
Coffee and a little fresh air will help
sober you up.
Only time will help a drinker sober up
- other methods just don’t work.
Stick with beer - it’s not as strong as
wine or whiskey.
A few beers are the same as a few
shots of whiskey or a few glasses of
wine.
What is a drink?
It is the alcohol in drinks that impairs human performance. It doesn’t make any difference
whether that alcohol comes from “a couple of beers,” from two glasses of wine, or two shots of
hard liquor. All of the following drinks contain the same amount of alcohol:
• A 12-ounce glass of 5% beer
• A 5-ounce glass of 12% wine
• A 1½-ounce shot of 80-proof liquor
How alcohol works
Alcohol goes directly from the stomach into the blood stream. A drinker can control the amount
of alcohol that he or she consumes by having fewer drinks or none. However, the drinker cannot
control how fast the body gets rid of alcohol. If you have drinks faster than the body can get rid
of them, you will have more alcohol in your body, and your driving will be more affected. The
amount of alcohol in your body is commonly measured by the Blood Alcohol Concentration
(BAC).
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 higher BAC), and your weight (a small person doesn’t have
to drink as much to reach the same BAC).
Alcohol and the 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, which are necessary for safe driving. One of the bad things
about this is it can keep drinkers from knowing they are getting drunk.
As blood alcohol concentration continues to build up, muscle control, vision, and coordination
are affected more and more. Eventually, a person will pass out.
How alcohol affects driving – All drivers are affected by drinking alcohol. Alcohol affects
judgment, vision, coordination, and reaction time. It causes serious driving errors, such as:
• Increased reaction time to hazards
• Driving too fast or too slow
• Driving in the wrong lane
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•
•
•
•
•
•
•
Running over the curb
Weaving
Straddling lanes
Quick jerky starts
Not signaling, failure to use lights
Running stop signs and red lights
Improper passing
These effects mean increased chances of a crash and chances of losing your driver’s license.
Accident statistics show that the chance of a crash is much greater for drivers who have been
drinking than for drivers who were not.
Other drugs
Besides alcohol, other legal and illegal drugs are being used more often. Laws prohibit
possession or use of many drugs. They prohibit being under the influence of any “controlled
substance” such as Amphetamines (including “pep pills” and “bennies”), narcotics or any other
substance that can make the driver unsafe. This could include a variety of prescriptions and
over-the-counter drugs (cold medicines) that may make the driver sleepy or otherwise affect
safe driving ability. However, possession and use of a 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 of legitimate drugs and medicines and to doctor’s orders
regarding possible effects. Stay away from illegal drugs. Don’t use any drug that hides fatigue.
The only cure for fatigue is rest. Alcohol can make the effects of other drugs much worse. The
safest rule is, don’t mix drugs with driving at all.
Use of drugs can lead to traffic accidents, resulting in death, injury, and property damage.
Furthermore, it can lead to arrest, fines, and jail sentences. It can also mean the end of a
person’s driving privilege.
Illness
Once in a while, you may become so ill that you cannot operate a 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 where you can safely stop.
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Section 2 - Transporting Cargo Safely
Inspecting and Securing Cargo
This section tells you about cargo safety. All drivers must understand some basic cargo safety
rules to get a Class A or B license. If you load cargo wrong, it can be a danger to others and to
yourself. Cargo that is not loaded or secured properly can cause other highway users to hit or
be hit by loose cargo. Loose cargo can hurt you or passengers during a quick stop or crash.
Inspecting your cargo
As part of your pre-trip inspection, check for overloads, poorly balanced weight, and cargo that
is not secured correctly. Also check that all outside storage compartment doors are latched
securely or locked.
Inspect the cargo and its securing devices again within 50 miles after beginning a trip and make
any adjustments needed. Inspect again after you have driven for 3 hours or 150 miles, and after
every break you take during the drive.
Weight and balance
It is important to know the weight and balance of your loaded vehicle. Overloading can have bad
effects on steering, braking, and speed control. Overloaded vehicles have to go very slowly on
upgrades. Worse, they may gain too much speed on downgrades. Stopping distance increases
and brakes can fail when forced to work too hard.
You are responsible to make certain your vehicle is not overloaded. Here are some definitions
of weight you should know:
• Gross vehicle weight (GVW) – The total weight of a single vehicle plus its load.
• Gross combination weight (GCW) – The total weight of a powered unit plus trailer(s)
plus the cargo.
• Gross combination weight rating (GCWR) – The weight specified by the manufacturer
of a vehicle as the combined loaded weight of that vehicle and a trailing vehicle.
• Axle weight – The weight transmitted to the ground by one axle or one set of axles.
• 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 manufacturer’s weight capacity
rating.
• Coupling device capacity – Coupling devices are rated for the maximum weight they
can pull and/or carry.
• Legal weight limits – You must keep weights within legal limits. States have
maximums for GVWs, GCWs, and axle weights. Often, maximum axle weights are set
by a bridge formula. A bridge formula permits less maximum axle weight for axles that
are closer together. This is to prevent overloading bridges and roadways.
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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 it is easier
to turn over. 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 or in the lower storage compartments.
Rolling over is also more likely in curves, if you have to swerve to avoid a hazard, or turns. Drive
slowly around turns and use a safe speed in curves.
Balance the weight. When loading cargo, keep the load balanced in the cargo area. Poor weight
balance can make vehicle handling unsafe. Too much weight on the steering axle can make
steering difficult and cause damage to 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. Also, too little weight on the driving axles can cause poor traction. The drive wheels
may spin easily. During bad weather, the truck or RV may not be able to keep going.
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Section 3 - Air Brakes
This section tells you about air brakes. You need this information for safe operation of air brakes
used on trucks, RVs, and buses. If you want to pull a trailer with air brakes, you will also need to
read Section 4: Combination Vehicles.
Air brakes use compressed air to make the brakes work. You can apply all the braking force you
need to each of the wheels of a heavy vehicle, even units pulling 2 or 3 trailers. Air brakes are a
safe way of stopping large vehicles if the brakes are well maintained and used right. However,
you must know more about air brakes than you need to know with the simple brake systems
used on light vehicles. Therefore, it is important for you to study this section.
Air brake systems are three braking systems combined: the service brake system, the parking
brake system, and the emergency brake system.
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 control.
The emergency brake system uses parts of the service and parking brake systems to
stop the vehicle in the event of a brake system failure.
The Parts of an Air Brake System
There are many parts to an air brake system. You should know about the parts discussed here.
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. If the compressor has its own oil supply, check the oil level before driving.
Air compressor governor
The governor controls 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 into the “cut-in”
pressure (around 100 psi) the governor allows the compressor to start pumping again.
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.
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Air tank drains
Compressed air usually has some water and some compressor oil in it that 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. Therefore, each air tank is equipped
with a drain valve in the bottom. There are two types:
• Manual – This is operated by turning a quarter turn or by pulling a cable. You must
drain the tanks yourself at the end of each day of driving; and
• Automatic – The water and oil is automatically expelled. Airtanks may be equipped for
manual draining as well. The automatic types are available with electric heating
devices. This helps prevent freeze up of the automatic drain in cold weather.
Figure
3-1
Manual Drain Valve
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 the 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 rid the system of water and oil (unless the system has automatic
drain valves).
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 mechanic.
The brake pedal
You put on the brakes by pushing down on the brake pedal. 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 goes too low, the brakes won’t work.
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When you push the brake pedal down, two forces push back against your foot. One force
comes from a spring. The second force comes from the air pressure going to the brakes. This
lets you feel how much air pressure is being applied to the brakes.
• 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
cam shaft. 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, and a spring pulls the brake shoes away from the drum,
allowing the wheels to roll freely again.
Figure
S-cam Air Brake
3-2
• 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.
Supply pressure gauges
All air-braked vehicles 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 needles). Dual systems will be discussed later. These gauges tell you how much pressure
is in the air tanks.
Application pressure gauge
The gauge shows how much air pressure you are applying to the brakes. This gauge is not on
all vehicles. When going down steep grades, increasing application pressure to 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 being out of adjustment, air leaks, or
mechanical problems.
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Low air pressure warning
A low air pressure warning signal is required on vehicles 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 cut-out pressure on older vehicle(s). The warning signal 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 will rise out of your
view when the pressure in the system goes above 60 psi. The manual reset type must be
placed in the “out-of-view” position manually. It will not stay in place until the pressure in the
system is above 60 psi.
On large buses, it is common for the low pressure warning devices to signal at 80-85 psi.
Stop light switch
Drivers behind you must be warned when you apply your brakes. The air brake system does
this with an electric switch that works by air pressure. The switch turns on the brake lights when
you apply the air brakes.
Front brake limiting valve
Some older vehicles (made before 1975) have a front brake limiting valve and a control in the
cab. The control is usually marked “normal” and “slippery.” When you put the control in the
“slippery” position, the limiting valve cuts the “normal” air pressure to the front brakes by half.
Limiting valves were used to reduce the chance of the front wheels skidding on slippery
surfaces. However, they actually reduce the stopping power of the vehicle. Front wheel braking
is good under all conditions. Tests have shown front wheel skids from braking are not likely,
even on ice. Make sure the control is in the “normal” position to have normal stopping power.
Many vehicles have automatic front wheel limiting valves. They reduce the air to the front
brakes except when the brakes are put on very hard (60 psi or more application pressure).
These valves cannot be controlled by the driver.
Spring brakes
All trucks, RVs, and buses must be equipped with emergency brakes and parking brakes. They
must be held on by mechanical force (because air pressure can eventually leak away). Spring
brakes are usually used to meet these needs. When driving, powerful springs are held back by
air pressure. If the air pressure is removed, the springs put 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 that causes all the air to be lost will also cause the
springs to put on the brakes.
Spring brakes will come fully on when air pressure drops to a range of 20 to 45 psi (typically 20
to 30 psi). Do not wait for the brakes to come on automatically. When the low air pressure
warning light and buzzer first come on, bring the vehicle to a safe stop right away, while you can
still control the brakes.
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The braking power of spring brakes depends on the brakes being in adjustment. If the brakes
are not adjusted right, neither the regular brakes nor the emergency parking brakes will work
right.
Parking brake controls
In newer vehicles with air brakes, you put on the parking brakes using a diamond shaped,
yellow, push-pull control knob. You pull the knob out to the 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 brake pedal down when the spring brakes are on. If you do, the
brakes could be damaged by the combined forces of the springs and the air pressure. Many
brake systems are designed so this will not happen. Not all systems are set up that way, and
those that are may not always work. It is much better to develop 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 dashboard 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 lever, the harder the spring brakes come on. They work
this way so you can control the spring brakes if the service brakes fail. 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 that can be used to release the spring brakes. This is so 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 break 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.
TEST YOUR KNOWLEDGE
1.
2.
3.
4.
5.
Why must air tanks be drained?
What is a supply pressure gauge used for?
All vehicles with air brakes must have a low air pressure warning signal. True or False?
What are spring brakes?
Front wheel brakes are good under all conditions. True or False?
Dual Air Brakes
Most newer heavy-duty vehicles use dual air brake systems for safety. A dual air brake system
has two separate air brake systems that use a single set of brake controls. Each system has its
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own set of brake controls. Each system has its own air tanks, hoses, lines, etc. One system
typically operates the regular brakes on the rear axle 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.”
Before driving a vehicle with a dual air system, allow time for the air compressor to build up a
minimum of 100 psi 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 repaired.
Walk-Around Inspection
Check Manual Slack Adjusters on S-cam brakes. Park on level ground and chock the wheels to
prevent the vehicle from moving. Turn off the parking brakes so you can move the slack
adjusters. Use gloves and pull hard on each slack adjuster that you can get to. 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 too much brake slack can be very hard to
stop. Out-of-adjustment brakes are the most common problem found in roadside inspections.
Be safe; check the slack adjusters.
Final Air Brake Check
Test low-pressure warning signal
Shut the engine off when you have enough air pressure that the low-pressure warning signal is
not on. Turn the electric power on and step on and off the brake pedal to reduce air tank
pressure. The low air 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 dual air systems.
If the warning signal doesn’t work, you could lose air pressure and you would not know it. This
could cause sudden emergency braking in a single circuit air system. In dual systems, the
stopping distance will be increased. Only limited braking can be done before the spring brakes
come on.
Check that the spring brakes come on automatically
Chock the wheels, release the parking brakes when you have enough air pressure to do it, and
shut the engine off. Step on and off the brake pedal to reduce the air tank pressure. The
“parking brake” knob should pop out when the air pressure falls to the manufacturer’s
specification, usually in a range between 20 and 40 psi. This causes the spring brakes to come
on.
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Check rate of air pressure build-up
With the engine at operating RPM, the pressure should build from 85 to 100 psi within 45
seconds in dual air systems. If the vehicle has larger than minimum air tanks, the build-up time
can be longer and still be safe. Check the manufacturer’s specifications. In single air systems
(pre 1975), typical requirements are pressure build-up from 50 to 90 psi within 3 minutes with
the engine at an idle speed of 600 to 900 RPM.
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 service brake
and time the air pressure drop. The loss rate should be less than 2 psi in one minute for single
vehicles, less than 3 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 3 psi in one
minute for single vehicles, more than 4 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 driving.
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
the manufacturer’s specifications.) Run the engine at a fast idle. 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 cut-in at about the manufacturer’s specified cut-in
pressure. The pressure should begin to rise.
If the air governor does not work as described, it may need to be fixed. A governor that does not
work right 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 a 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
5 mph), and apply the brakes firmly using the brake pedal. Note any vehicle “pulling” to one
side, unusual feel, or delayed stopping action.
TEST YOUR KNOWLEDGE
1. What is a dual air brake system?
2. What are slack adjusters?
3. How can you check slack adjusters?
4. How can you test the low-pressure warning signal?
Page5.46 How
of 62 can you check that the spring brakes come on automatically?
6. What are the maximum leakage rates?
Revised 5/10
Using Air Brakes
Normal stops
Push the brake pedal down. Control 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 down close to
idle. When stopped, select a starting gear.
Emergency stops
You should brake so you can steer and so your vehicle stays in a straight line. Use one of the
following two methods.
• Control braking – This method is also called “squeeze” braking. Put on the brakes as
hard as you can without locking the wheels. Do not turn the steering wheel while doing
this. If you need to make large steering adjustments or if you feel the wheels sliding,
release the brakes. Brake again as soon as the tires get traction.
• Stab braking – Press on the brake pedal as hard as you can. Release the brakes
when the wheels lock up and as soon as the wheels start rolling, put on the brakes
fully again. It can take up to one second for the wheels to start rolling after you release
the brakes. Make sure you stay off the brakes long enough to get the wheels rolling
again. Otherwise the vehicle may not stay in a straight line.
Stopping distance
We talked about stopping distance in Section 2 under “speed and stopping distance.” With air
brakes there is an added delay: the time required for the brakes to work after the brake pedal is
pushed. With hydraulic brakes, used on cars and light/medium trucks, the brakes work instantly.
However, with air brakes, it takes a little time for the air to flow through the lines to the brakes –
generally one-half second or more. Thus, the total stopping distance for vehicles with air brake
systems is made up of four different factors: perception distance, reaction distance, brake lag
distance, and effective braking 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 300
feet. This is longer than a football field.
Braking on downgrades
When you use the brakes, they get hot. Brakes can take a lot of heat. However, brakes will stop
working if there is too much heat. Excessive heat is caused by trying to slow down from too high
a speed too many times or too quickly. Brakes will fade when they get too hot. You will have to
push harder on the pedal to get the same stopping force. They can fade so badly they will not
slow you down.
It is always important for the brakes to be adjusted right. However, it is especially important
when going down steep grades. In addition to proper slack adjustment, the air brake system
should be balanced to give about the same braking at each of the wheels. Otherwise, some
brakes will do more work than others. They will heat up and lose some of their stopping power.
Brake balance can be tested and fixed by good air brake mechanics.
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Low air pressure warning
If the low air pressure warning comes on, stop and safely park your vehicle as soon as possible.
There might be an air leak in the system. Controlled braking is possible only while enough air
remains in the air tanks. The spring brakes will come on when the air pressure drops into the
range 20 to 45 psi. A heavily loaded vehicle will take a long distance to stop because the spring
brakes do not work on all axles. Lightly loaded vehicles or vehicles on slippery roads may skid
out of control when the spring brakes come on. It is much safer while there is enough air in the
tanks to use the foot brakes.
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 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 to brake fade. Brake fade
results from excessive heat causing chemical changes in the brake lining that reduce friction
and also causes expansion of the brake drums. As the overheating drums expand, the brake
shoes and linings have to move farther to contact the drums, and the force of this contact is also
reduced. Continued overuse may increase brake fade until the vehicle cannot be slowed down
or stopped at all.
Brakes can also fade because of improper adjustment. To safely control a vehicle, every brake
must do its share of the work. If some brakes are out of adjustment, they will not be doing their
share. The other brakes can overheat and fade, and there will not be sufficient braking available
to control the vehicle(s). Brakes can get out of adjustment quickly, especially when they are hot.
Therefore, brake adjustment must be checked frequently.
Proper braking technique
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 proper low gear, the following is the proper braking
technique:
1. Apply the brakes just hard enough to feel a definite shutdown.
2. When your speed has been reduced to approximately 5 mph below your “safe” speed,
release the brakes.
3. When you speed has increased to your “safe” speed, repeat steps 1 and 2.
For example – If your “safe” speed is 40 mph, you would not apply the brakes until your speed
reaches 40 mph. You now apply the brakes hard enough to gradually reduce your speed to 35
mph and then release the brakes. Repeat this as often as necessary until you have reached the
end of the downgrade.
Parking brakes
Any time you park, use the parking brakes, except as noted below. Pull the parking brake
control knob out to apply the parking brakes, push it in to release them. The control will be a
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yellow, diamond shaped knob labeled “parking brakes” on newer vehicles. On older vehicles, it
may be a round blue knob or some other shape (including a lever that swings from side to side
or up and down).
Don’t use the parking brakes if the brakes are very hot from just having come down a steep
grade, or if the brakes are very wet in freezing temperatures. If they are used while they are
very hot, they can be damaged by the heat. If they are used in freezing temperatures when the
brakes are very wet, they can freeze so the vehicle cannot move. Use wheel chocks to hold the
vehicle. Let hot brakes cool before using the parking brakes. If the brakes are wet, use the
brakes lightly while driving in a low gear to heat and dry them.
If your vehicle does not have automatic air tank drains, drain your tanks at the end of each
working day to remove moisture and oil. Otherwise the brakes could fail.
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Section 4 - Combination Vehicles
This section provides information needed to pass the tests for combination vehicles (tractortrailer, doubles, triples, straight truck and trailer). The information is only to give you the
minimum knowledge needed for driving common combination vehicles. This section covers
driving combinations, coupling and uncoupling, and inspection combinations.
Combination vehicles are usually heavier, longer, and require more driving skills than single
commercial vehicles. This means that drivers of combination vehicles need more knowledge
and skill than drivers of single vehicles. In this section, we talk about some important safety
factors that apply specifically to combination vehicles.
Rollover risks
More than half of truck driver deaths in crashes are from truck rollovers. When more cargo is
piled up in a truck, the “center of gravity” moves higher up from the road. The truck becomes
easier to turn over. Fully loaded rigs are 10 times more likely to roll over in a crash than empty
rigs.
Do the following two things to help prevent a rollover.
o
o
Keep the cargo as close to the ground as possible, and go slow around turns. Keeping
the cargo low is even more important in combination vehicles than in straight trucks.
Keep the load centered on your rig. If the load is to one side, it can cause the trailer to
lean and a rollover is more likely.
Figure 4-1
Influence of
Combination
Type on
Rearward
Amplification
Page 50 of 62
(From R.D. Ervin, R.L. Nisonger, C.C. MacAdam, and P.S. Fancher, "Influence of size and weight
variables on the stability and control properties of heavy trucks", University of Michigan
Transportation Research Institute, 1983.)
Revised 5/10
Trucks with trailers have a dangerous “crack-the-whip” effect. When you make a quick lane
change, the crack-the-whip effect can turn the trailer over. There are many accidents where only
the trailer has overturned.
“Rearward amplification” causes the crack-the-whip effect. Figure 4-1. Page 50 shows eight
types of combination vehicles and the rearward amplification each has in a quick lane change.
Rigs with the least crack-the-whip effect are shown at the top and those with the most are at the
bottom. Rearward amplification of 2.0 in the chart means that the rear trailer is twice as likely to
turn over as the tractor. You can see that triples have a rearward amplification of 3.5. This
means you can roll the last trailer of triples 3.5 times as easily as a five-axle tractor-semi.
Steer gently and smoothly when you are pulling trailers. If you make a sudden movement with
your steering wheel, you could tip over a trailer. Follow far enough behind other vehicles (at
least one second for each ten feet of your vehicle length, plus another second if going over 40
mph). Look far enough down the road to avoid being surprised and having to make a sudden
lane change. At night, drive slow 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.
Brake early
Control your speed whether fully loaded or empty. Large
combination vehicles that are empty take longer to stop
than when they are fully loaded. When lightly loaded, the
very stiff suspension springs and strong brakes give poor
traction and make it very easy to lock up the wheels. Your
trailer can swing out and strike other vehicles. Your tractor
can jackknife very quickly. See Figure 4-2.
Figure 4-2 Tractor Jackknife
You also must be very careful about driving “bobtail” tractors (tractors without semi-trailers).
Tests have shown that bobtails can be very hard to stop smoothly. It takes them longer to stop
than a tractor-semi trailer loaded to maximum gross weight.
In any combination rig, allow a lot of following distance and look far enough ahead so you can
brake early. Don’t be caught by surprise and have to make a “panic” stop.
Prevent trailer skids
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
jackknife.” This is shown to the right.
Figure 4-3
Trailer Jackknife
Recognizing the skid
The earliest and best way to recognize
that the trailer has started to skid is by
seeing it in your mirrors. Any time you
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apply the brakes hard, check the mirrors to make sure the trailer is staying where it should.
Once the trailer swings out of your lane, it is very difficult to prevent a jackknife.
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.
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Section 5 - Pre-Trip Vehicle Inspection Test
This section covers internal and external inspections. During the pre-trip inspection, you must
show that the vehicle is safe to drive. You will have to walk around the vehicle and point to or
touch each item and explain to the examiner what you are checking and why. You may not have
to crawl under the hood or under the vehicle. It is important to inspect your truck or bus prior to
leaving on a trip for safety reasons.
All Vehicles
Study the following vehicle parts for the type of vehicle you will be using during the noncommercial skills test. You should be able to identify each part and tell the examiner what you
are looking for or inspecting.
Engine Compartment Only
• Leaks/Hoses/Wiring
o Look for puddles on the ground.
o Look for dripping fluids on the underside of the engine and transmission.
o Inspect hoses for condition and leaks.
o Look for worn electrical wiring insulation.
• Oil Level
o Indicate where the dipstick is located.
o See that the oil level is within safe operating range. Level must be above refill
mark.
• Coolant Level
o Inspect reservoir sight glass; or
o If engine is not hot, remove the radiator cap and check for visible coolant level.
• Power Steering Fluid
o Indicate where power steering fluid dipstick is located.
o Check for adequate power steering fluid level. Level must be above refill mark.
• Engine Compartment Belts
o Check the following belts for snugness (up to ¾ inch play at center of belt),
cracks, or frays.
ƒ Power steering belt
ƒ Alternator belt
ƒ Air compressor belt
Note - if any of the components listed above are not belt-driven, you must tell the
examiner which component(s) are not belt-driven and ensure the component(s)
are operating properly (not damaged or leaking) and are mounted securely.
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Cab Check/Engine Start
• Oil Pressure Gauge
o Make sure the oil pressure gauge is working.
o Check that pressure gauge shows increasing or normal oil pressure or that the
warning light goes off.
o If equipped, the oil temperature gauge should begin a gradual rise to the normal
operating range.
• Ammeter/Voltmeter
o Check that gauges show the alternator and/or the generator is charging or that
warning light is off.
• Mirrors and Windshield
o Mirrors should be clean and adjusted properly from the inside.
o Windshield should be clean with no illegal stickers, no obstructions, or damage to
the glass.
• Wipers/Washers
o Check that wiper arms and blades are secure, not damaged, and operate
smoothly.
o If equipped, windshield washers must operate correctly.
• Horn
o Check that the air horn and/or electric horn are in working condition.
• Heater/Defroster
o Test that the heater and defroster work.
Air Brake Check (if equipped)
Failure to perform an air brake check will result in an automatic failure of the vehicle inspection
test. Air brake safety devices vary. However, this procedure is designed to see that any safety
device operates correctly as air pressure drops from normal to a low air condition. For safety
purposes, in areas where an incline is present, you will use wheel chocks during the air brake
check. The proper procedures for inspecting the air brake system are as follows:
•
•
•
•
•
•
With the engine running, build the air pressure to governed cut-out (100-125 psi).
Shut off the engine, turn key to ON position.
Chock the wheels.
If necessary, release the tractor protection valve and parking brake, push in valves.
Fully apply the foot brake and hold it for one minute.
Check the air gauge to see if the air pressure drops more than three pounds in one
minute (single vehicle) or four pounds in one minute (combination vehicles).
• Begin fanning off the air pressure by rapidly applying and releasing the foot brake.
The low air warning device should activate before the air pressure drops below 60 psi.
• Continue to fan off the air pressure. At approximately 40 psi on a tractor-trailer
combination vehicle, the tractor protection valve and parking brake valve should close
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(pop out). On other combination and single vehicle types, the parking brake valve
should close (pop out).
Light/Reflectors
Check that all external lights and reflective equipment are clean and functional. Light and
reflector checks include the following:
•
•
•
•
•
•
•
Clearance lights (red on rear, amber elsewhere)
Headlights (low and high beams)
Taillights
Turn signals
4-way flashers
Brake lights
Red reflectors on rear, and amber reflectors elsewhere
Note: Checking of brakes, turn signals, and 4-way flasher functions must be done separately.
Wheels
The following must be inspected on every vehicle:
• Rims – Check for damage or bent rims. Rims cannot have welding repairs.
• Lug nuts – Check that all lug nuts are present, free of cracks and distortions such as
rust trails or shiny threads. Make sure bolt holes are not cracked or distorted. Ensure
there are no signs of looseness.
• Tread depth – Check for minimum tread depth: 4/32” on steering axle tires, and 2/32”
on all other tires.
• Tire condition – Check that tread is evenly worn and look for cuts or other damage to
tread or sidewalls. Also make sure that valve caps and stems are not missing, broken,
or damaged.
• Tire inflation – Check for proper inflation by using a tire gauge, or by striking tires
with a mallet or other similar device.
Note: You will not get credit if you simply kick the tires to check for proper inflation.
Tractor/Coupling
•
Air/Electric Lines
o Listen for air leaks.
o Check that air hoses and electric lines are not chafed, spliced, or worn. The steel
braid should not show through.
o Make sure air and electric lines are not tangled, pinched, or dragging against
tractor parts.
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•
Mounting Bolts
o Look for loose or missing mounting brackets, clamps, bolts, or nuts. Both the fifth
wheel and the slide mounting must be solidly attached.
o On other types of coupling systems (ball hitch, pintle hook, etc.) inspect all
coupling components and mounting brackets for missing or broken parts.
o Rings – These connect the trailer to the pintle hook. Inspect the ring for cracks,
excessive wear, or other damage.
o Safety Latch – This keeps the hook and ring from separating. Check to make sure
the latch is in the down position and locked. Ensure it is not loose or damaged.
•
Locking Jaws
o Look into fifth wheel gap and check that locking jaws are fully closed around the
kingpin.
o On other types of coupling systems (ball hitch, pintle hook, etc.) inspect the
locking mechanism for missing or broken parts and make sure it is locked
securely. If present, safety cables or chains must be secure and free of kinks and
excessive slack.
•
Platform (fifth wheel) – Check for cracks or breaks in the platform structure that
supports the fifth wheel skid plate.
•
Release Arm (fifth wheel) – If equipped, make sure the release arm is in the
engaged position and the safety latch is in place.
•
Kingpin/Apron/Gap/Trailer Tongue
o Check that the kingpin is not bent.
o Make sure the visible part of the apron is not bent, cracked, or broken.
o Check that the trailer is laying flat on the fifth wheel skid plate (no gap).
•
Locking Pins
o If equipped, look for loose or missing pins in the slide mechanism of the sliding
fifth wheel. If air powered, check for leaks.
o Make sure locking pins are fully engaged.
o Check that the fifth wheel is positioned properly so that the tractor frame will clear
the landing gear during turns.
o On other types of coupling systems, inspect the trailer tongue to ensure it is not
bent, cracked, or otherwise damaged.
Trailer
•
Air/Electrical Connections (trailer front)
o Check that trailer air connectors are sealed and in good condition.
o Make sure glad hands are locked in place, free of damage, or air leaks.
o Make sure the trailer electrical plug is firmly seated and locked in place.
•
Tandem Release Arm/Locking Pins – If equipped, make sure the locking pins are
fully engaged and in the proper position. Ensure it is not worn, rusted, or damaged.
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Section 6 - Basic Vehicle Control Skills Test
Your basic control skills will be tested using all of the following exercises, off-road or somewhere
on the street during the road test:
1. Forward Stop
2. Straight line backing
3. Alley dock
These exercises are show in Figures 6-1 through 6-3.
Scoring
Cross boundaries
The examiner will score the number of times you touch or cross over an exercise boundary line
with any portion of your vehicle. Each encroachment will count as an error.
Pull-ups
In some of the exercises, the examiner will also score the number of times you stop and change
direction or pull-up during the exercise.
Exercises
Forward Stop – You will be asked to drive forward between
two rows of cones and bring your vehicle to a complete stop
as close as you can to the exercise boundary marked by an
end line or set of cones (without going beyond the line of
cones). See figure 6-1 to the right.
Figure 6-1
Forward Stop
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Straight line backing – You will be asked to back your
vehicle in a straight line between two rows of cones
without touching or crossing over the exercise
boundaries.
Figure 6-2
Straight Line
Backing
Alley dock – You will be asked to sight-side back your vehicle into an alley, bring the rear of
your vehicle as close as possible to the rear of the alley without going beyond the exercise
boundary marked by a line or row of cones.
Figure 6-3
Alley Dock
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Section 7 - On-Road Driving Test
Exercises
During the driving test, you must wear your safety belt, obey all traffic signs, signals, and laws,
and complete the test without an accident or moving violation.
You will drive over a test route that has a variety of traffic situations. At all times during the test,
you must drive in a safe and responsible manner.
The examiner will score you on specific driving maneuvers as well as on your general driving
behavior during the test. The examiner will give you directions and you will have plenty of time
to do what is asked. You will not be asked to drive in an unsafe manner.
You will be scored on your overall performance in the following general driving behavior
categories:
Clutch Usage (manual transmission)
o
o
o
o
Always use your clutch to shift.
Double-clutch if the vehicle is equipped with non-synchronized transmission.
Do not rev or lug the engine.
Do not ride the clutch to control the speed, coast with the clutch depressed, or “pop”
the clutch.
Gear Usage (manual transmission)
o
o
o
Do not grind or clash gears.
Select gear that does not rev or lug engine.
Do not shift in turns and intersections.
Brake Usage
o
o
Do not ride or pump brake.
Do not brake harshly – brake smoothly using steady pressure.
Lane Usage
o
o
o
o
o
Do not put vehicle over curbs, sidewalks, or lane markings.
Stop behind stop lines, crosswalks, or stop signs.
Complete a turn in the proper lane on a multiple lane road – vehicle should finish a
left turn in the lane directly to the right of the center line.
Finish a right turn in the right-most lane.
Move to or remain in the right-most lane unless lane is blocked.
If your test route does not have certain traffic situations, you may be asked to simulate a traffic
situation. You will do this by telling the examiner what you are or would be doing if you were in
that traffic situation.
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How You Will Be Tested
Turns
You have been asked to make a turn:
o Check traffic in all directions.
o Use your turn signals and safely get into the lane needed for the turn.
As you approach the turn:
o Use your turn signals to warn others of your turn.
o Slow down, smoothly change gears as needed to keep power, but do not coast
unsafely. Unsafe coasting occurs when your vehicle is out of gear for more than the
length of your vehicle.
If you must stop before making the turn:
o Come to a smooth stop without skidding.
o Come to a complete stop behind the stop line, crosswalk, or stop sign.
o If stopping behind another vehicle, stop where you can see the rear tires on the
vehicle ahead of you (safe gap).
o Do no let your vehicle roll.
o Keep the front wheels aimed straight ahead.
When ready to turn:
o Check traffic in all directions.
o Keep both hands on the steering wheel during the turn.
o Do not change gears during the turn.
o Keep checking your mirror to make sure the vehicle does not hit anything on the
inside of the turn.
o Vehicle should not move into oncoming traffic.
o Vehicle should finish turn in correct lane.
After turn:
o Make sure turn signal is off.
o Get up to speed of traffic, use turn signal, and move into right-most lane when safe
to do so, if not already there.
Intersections
As you approach an intersection:
o Check traffic thoroughly in all directions (we’re looking for head movement).
o Decelerate gently.
o Brake smoothly, and if necessary, change gears.
o If necessary, come to a complete stop (no coasting) behind any stop signs, signals,
sidewalks, or stop lines, maintaining a safe gap behind any vehicle in front of you.
o Your vehicle must not roll forward or backward.
When driving through an intersection:
o Check traffic thoroughly in all directions.
o Decelerate and yield to any pedestrians and traffic in the intersection.
o Do not change lanes or shift gears while proceeding through the intersection.
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o
Keep your hands on the wheel.
Once through the intersection:
o Continue checking traffic.
o Accelerate smoothly and change gears as necessary.
Urban and Rural Straight
During this part of the test, you are expected to make regular traffic checks and maintain a safe
following distance. Your vehicle should be centered in the proper lane (right-most lane), and you
should keep up with the flow of traffic but not exceed the posted speed limit.
Urban and Rural Lane Changes
During the multiple lane portions of the urban and rural sections, you will be asked to change
lanes to the left and then back to the right. You should make the necessary traffic checks first,
then use proper signals and smoothly change lanes when it is safe to do so.
Stop and Start
For this maneuver, you will be asked to pull your vehicle over to the side of the road and stop as
if you were going to get out and check something on your vehicle. You must check traffic
thoroughly in all directions and move to the right-most lane or shoulder of the road.
As you prepare to stop:
o Check traffic.
o Activate your right-turn signal.
o Decelerate smoothly, brake evenly, change gears as necessary.
o Bring your vehicle to a full stop without coasting.
Once stopped:
o Vehicle must be parallel to the curb or shoulder of the road and safely out of the
traffic flow.
o Vehicle should not be blocking driveways, fire hydrants, intersections, signs, etc.
o Cancel your turn signal.
o Activate your 4-way emergency flashers.
o Apply the parking brake.
o Move the gear shift to neutral or park.
o Remove your feet from the brake and clutch pedals.
When instructed to resume:
o Check traffic and your mirrors thoroughly in all directions.
o Turn off your 4-way flashers.
o Activate the left-turn signal.
o When traffic permits, you should release the parking brake and pull straight ahead.
o Do not turn the wheel before your vehicle moves.
o Check traffic from all directions, especially to the left.
o Steer and accelerate smoothly into the proper lane when safe to do so.
o Once your vehicle is back into the flow of traffic, cancel your left-turn signal.
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Curve
When approaching a curve:
o Check traffic thoroughly in all directions.
o Before entering the curve, reduce speed so further braking or shifting is not required
in the curve.
o Keep vehicle in the lane.
o Continue checking traffic in all directions.
Upgrade
As you approach the upgrade:
o Select the proper gear to maintain speed and not lug the engine.
o Check the traffic thoroughly in all directions and move to the right-most or curb lane.
o If legal to do so, use 4-way flashers if traveling too slowly for the flow of traffic.
Downgrade
Before starting down the grade:
o Downshift as needed to help control engine speed and test brakes by gently applying
the foot brake to ensure they are functioning properly.
o As your vehicle moves down the grade, continue checking traffic in all directions,
stay in the right-most or curb lane, and if legal to do so, use 4-way flashers if your
vehicle is moving too slowly for traffic.
o Increase following distance and observe the following downhill braking procedures:
ƒ Select a “safe” speed, one that is not too fast for the weight of the vehicle,
length and steepness of the grade, weather, and road conditions.
ƒ Once a “safe” speed has been reached, apply the brake hard enough to feel
a definite slowdown.
ƒ When speed has been reduced to 5 mph below the “safe” speed, release the
brake.
ƒ Once speed has increased to the “safe” speed, repeat the procedure.
When operating any commercial vehicle, do not ride the clutch, race the engine, change
gears, or coast while driving down the grade. At the bottom of the grade, be sure to
cancel your 4-way flashers.
Not all test routes will contain an area of sufficient grade to test your skill adequately. Therefore,
you may be asked to simulate (verbally) driving up and down a steep hill. You must be familiar
with the upgrade/downgrade procedures so that you can explain and/or demonstrate them to
the examiner at any time during the driving test.
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