Child safety in cars – Literature review

Child safety in cars – Literature review
VTI rapport 489A • 2003
Child safety in cars
– Literature review
Anna Anund
Torbjörn Falkmer
Åsa Forsman
Susanne Gustafsson
Ylva Matstoms
Gunilla Sörensen
Thomas Turbell
Jan Wenäll
VTI rapport 489A · 2003
Child safety in cars – Literature review
Anna Anund
Torbjörn Falkmer
Åsa Forsman
Susanne Gustafsson
Ylva Matstoms
Gunilla Sörensen
Thomas Turbell
Jan Wenäll
Publisher:
Publication:
VTI-rapport 489A
SE-581 95 Linköping Sweden
Published:
Project code:
2003
40506
Project:
Child safety in cars
Author:
Sponsor:
Anna Anund, Torbjörn Falkmer, Åsa Forsman, Susanne
Gustafsson, Ylva Matstoms, Gunilla Sörensen, Thomas
Turbell och Jan Wenäll.
Swedish National Road Administration
Title:
Child safety in cars - Literature review
Abstract (background, aims, methods, results) max 200 words:
In order to study child safety in cars, international literature was reviewed with respect to road
vehicle transportation for children, with the focus being on the age up to 12 years. The review
included literature in English and Swedish. Furthermore, the review was limited to focus on results
from Australia, the U.K., the USA and Sweden.
To ensure that all children are protected as passengers in cars, several aspects needed to be
considered. Within this study, the focus was, hence, on legal aspects and recommendations, traffic
fatalities and serious injuries, the safety consequences for children due to the car development
(airbags (SRS) and installation systems), use and misuse of child restraint systems (CRS) regarding
medical, technical and user aspects, measurements for improvements, e.g. campaigns and, finally,
children with disabilities. The review focused mainly on literature from 1990 until today.
The main conclusions were that:
* Available statistics show that rearward facing CRS is a good preventive measure to take for
enhancement of traffic safety.
* Impacts from the in-safety development of cars on choosing and mounting safety devices for
children were found to be a crucial issue.
* Children exposed to an airbag deployment can be fatally injured, despite being seated in an
approved child restraint system.
* In Sweden and the U.K. the level of child restraint usage among infants and small children was
found to be at least 95% in the front seat and approximately at the same level in the rear seat. Even
though the levels of usage in several countries were high, the level of misuse was alarmingly high
(90%).
* The road transportation of children with disabilities was found to be complex and insufficiently
described in the literature.
The literature review was funded by the Swedish National Road Administration.
ISSN:
0347-6030
Language:
No. of pages:
English
86 + 1 appendix
Utgivare:
Publikation:
VTI meddelande 489A
581 95 Linköping
Utgivningsår:
Projektnummer:
2003
40506
Projektnamn:
Barns säkerhet i bil
Författare:
Uppdragsgivare:
Anna Anund, Torbjörn Falkmer, Åsa Forsman, Susanne
Gustafsson, Ylva Matstoms, Gunilla Sörensen, Thomas
Turbell och Jan Wenäll.
Vägverket
Titel:
Barns säkerhet i bil - en litteraturstudie
Referat (bakgrund, syfte, metod, resultat) max 200 ord:
Föreliggande litteraturstudie har genomförts med syfte att sammanfatta kunskapsläget avseende barns
säkerhet i bil. Litteraturen har delats in i områdena; lagar/rekommendationer, olyckor med
dödlig/svår personskada, säkerhetskonsekvensen för barn i bil avseende bilutvecklingen (speciellt
avseende installationssystem och krockkuddar), användning/felanvändning sett ur ett medicinskt,
tekniskt och handhavande perspektiv, åtgärder/kampanjer samt situationen för barn med
funktionshinder.
Litteraturstudien omfattar i huvudsak litteratur om barn i åldern 0–12, vidare har fokus varit på
litteratur skriven från 1990 och fram till idag. Endast litteratur skriven på engelska och svenska har
ingått och ett fokus har varit på studier från Australien, England, USA och Sverige.
Litteraturen visar att det säkraste sättet att färdas i bil om man är barn är att åka bakåtvänt. Det
kräver dock att skyddsutrustningen som används är rätt monterad, att bältet som håller fast barnet är
korrekt placerat och barnet inte är placerad på en plats där det finns krockkudde.
I Sverige och i England är användningen av skyddsutrustning för spädbarn som åker bil, cirka
95 procent. Detta innebär inte att alla dessa barn åker säkert. Litteraturstudien visar att
felanvändningen är stor. Vidare konstateras att ju äldre barnen är desto sämre skyddas de. För barn
med funktionshinder är det långt ifrån en självklarhet att färdas säkert. Litteraturstudien har
finansierats av Vägverket.
ISSN:
0347-6030
Språk:
Antal sidor:
Engelska
86 + appendix
Preface
This VTI report is a literature review within the field child safety in cars. This
study has been financed by the Swedish National Road Administration (SNRA).
The responsible person at SNRA has been Anders Lie.
The literature was reviewed in collaboration between researchers at Swedish
National Road and Transport Research Institute (VTI). Contributors to the report
have been Anna Anund, Torbjörn Falkmer, Åsa Forsman, Susanne Gustafsson,
Ylva Matstoms, Gunilla Sörensen, Thomas Turbell and Jan Wenäll.
The contributors have been responsible for different topics within the field
children in cars. The responsibility has been as follows;
Anna Anund
Legal aspects
Torbjörn Falkmer
Children with disabilities and the introduction section
Åsa Forsman
Car development – the implications of airbags
Susanne Gustafsson
Measures for improvements - campaigns
Ylva Matstoms
Traffic fatalities and serious injuries
Gunilla Sörensen
Use and misuse of restraints
Thomas Turbell
Car development – installation systems
Jan Wenäll
Data from accidents and crash tests
I also wish to thank Gunilla Sjöberg and Anita Carlsson at VTI, and Catharina
Arvidsson and Claes Eriksson at BIC, VTI, for additional work on the references,
constructive comments on specific areas and for layout work and for finalising the
report.
Torbjörn Falkmer and I have edited the report. I have been coordinating the
project.
I would like to thank all authors for their qualified and irreplaceable work.
Linköping, May 2003.
Anna Anund
VTI rapport 489A
Table of contents
Summary
5
Sammanfattning
9
Terminology and abbreviations
13
1
1.1
1.2
Introduction
Children in traffic and the “Vision Zero”
Child anatomy
16
16
16
2
The aim of the study and its limitations
19
3
Method
20
4
4.1
4.1.1
4.1.2
4.1.3
4.1.4
4.2
4.3
Results
Legal aspects
Australia
U.K.
USA
Sweden
Traffic fatalities and serious injuries on the international scene
Car development, installation systems and its implications for
child safety
Car development
Installation systems
Data from accidents and crash tests regarding child safety
seats
Use and misuse of restraints – observations and
questionnaires
Australia
U.K.
USA
Sweden
Socioeconomic aspects
Measures for improvement – Campaigns
Australia
U.K.
USA
Sweden
Children with disabilities
Children with disabilities and transportation safety equipment
Regulations and standards
Travel habits
Transport providers
Transport procedures
Perceived risks and safety problems according to parents and
drivers
22
22
23
23
24
25
25
4.3.1
4.3.2
4.4
4.5
4.5.1
4.5.2
4.5.3
4.5.4
4.6
4.7
4.7.1
4.7.2
4.7.3
4.7.4
4.8
4.8.1
4.8.2
4.8.3
4.8.4
4.8.5
4.8.6
5
5.1
Conclusions and discussion
Legal aspects
VTI rapport 489A
27
27
29
29
34
34
34
35
42
45
46
46
49
49
53
54
54
54
56
59
59
61
64
64
5.2
5.3
5.4
5.5
5.6
5.7
Traffic fatalities and serious injuries on the international scene
Car development, installation systems and its implication
for child safety
Data from accidents and crash test regarding child safety seats
Use and misuse of restraints
Measures for improvement – Campaigns
Children with disabilities
65
68
69
70
70
6
Suggestions for future research and development
73
7
References
76
Appendix:
65
Available statistics and sources
VTI rapport 489A
Child safety in cars – Literature review
by Anna Anund, Torbjörn Falkmer, Åsa Forsman, Susanne Gustafsson,
Ylva Matstoms, Gunilla Sörensen, Thomas Turbell and Jan Wenäll
Swedish National Road and Transport Research Institute (VTI)
SE-581 95 Linköping, Sweden
Summary
Available statistics show that rearward facing CRS (Child Restraint Systems)
is a good preventive measure to take for enhancement of traffic safety.
Impacts from the in-safety development of cars on choosing and mounting
safety devices for children were found to be a crucial issue. Children exposed
to an airbag deployment can be fatally injured, despite being seated in an
approved child restraint system.
In Sweden and the U.K. the level of child restraint usage among infants
and small children was found to be at least 95 % in the front seat and
approximately at the same level in the rear seat. Even though the levels of
usage in several countries were high, the level of misuse was alarmingly high
(90 %).
The road transportation of children with disabilities was found to be
complex and insufficiently described in the literature.
This literature review has been divided into different topics within the area child
safety in cars. The review has been focused on legal aspects, traffic fatalities and
serious injuries, the impact of the developments of cars for choosing safety
demands for children, the advantage of rearward facing child safety seats as
opposed to forward facing ones, the consequence of incorrect use, misconception,
measures for improvements and children with disabilities. The review focused
mainly on literature from 1990 until today.
A comparison of laws and recommendations in Sweden, the USA, the U.K. and
Australia revealed large differences with respect to e.g. the children’s age, height
and weight related to CRS, if the CRS had to be rearward faced or not, and the
age that the responsibility of the driver, concerning the child’s safety in the car,
was abolished.
Data concerning accidents for 2002 was compiled. However, data with oneyear age groups was rarely published, which was unfortunate since the usage of
CRS types and exposure rates were likely to vary between children of different
ages.
The available statistics showed that rearward facing CRS was a good
preventive measure to take for enhancement of traffic safety. In the few accident
investigations found, the main concern was that most injured or killed children
were not restrained at all. Head injuries were the main fatality cause. The second
common misconception seemed to be putting too small children into forward
facing seats. Using the CRS incorrectly was also reported but to a lesser degree.
Improperly restrained children, in particular infants and small children, in ageappropriate restraint systems sustained a greater proportion of severe or moderate
injuries than properly restrained children who were in the wrong restraints for
their size.
VTI rapport 489A
5
In the reviewed literature, the physiological differences between children and
adults were mentioned and shown in various ways, leading to the conclusion that
children always need specific or additional protection in the car.
A good way of determining that a CRS was constructed for proper protection
for a child was approval according the ECE R 44/03 tests. A field of crash safety
protection that needs further investigation was the strength of the rear seat back.
Impacts from the in-safety development of cars on choosing and mounting
safety devices for children were found to be a crucial issue. Children exposed to
an airbag deployment can be fatally injured, despite being seated in an approved
child restraint system. The conflict between children and airbags initiated a
questionnaire based survey. The results from 23 general agencies showed that
recommendations from most agents were to place children in the back seat;
although the centre rear seat position was only recommended if equipped with a
lap/shoulder belt, a recommendation not undisputed and, hence, it was considered
important to address the question of how to deactivate the airbag.
In Sweden and the U.K., the level of child restraint usage among infants and
small children (toddlers) was found to be at least 95 % in the front seat and
approximately at the same level in the rear seat. In these countries, however, the
level of restraint use among older children was significantly lower than for
younger children.
Even though the levels of usage in several countries were high, the level of
misuse was alarmingly high (90 %). Examples of serious misuse given were:
dangerous buckle crunching and rearward-facing seats in front of an airbag.
Common misuses were for example loose seat belts and harness straps, restraint
devices not adequately secured to the seat or incompatible with the car, etc. The
rates of misuse were, not surprisingly, often reported to be higher with systems
where both the seat and the child need to be secured, such as infant seats and
convertible restraints. An important finding in several studies was that parents and
other caregivers think that their child is correctly restrained, while observations
prove the opposite. Several studies showed that parents who were seeking or
receiving information about car child safety had a lower level of misuse.
In many studies a relation was found between level of restraint use and
different socio-economic factors. Examples of factors found to be related to high
restraint usage were: high income and high level of education. Situations or
groups in which restraint usage was found to be low were for example in the
group of children from minority groups, such as immigrants.
The different campaigns described in the literature aimed to decrease the
number of child fatalities in cars by emphasizing the importance of seat belt and
CRS usage. The results from the campaigns were analyzed or reported in different
ways. Some of the campaigns measured the awareness of the activities in the
campaign; others measured the fatalities and the usage of the restraints prior to
and following the campaign.
The road transportation of children with disabilities was found to be complex
and insufficiently described in the literature. Some regulations and standards were
identified. Two Swedish studies, one with the focus on children with locomotor
disabilities and the other with the focus on children with autism spectrum
disorders showed that the vast majority of journeys were made in the family
vehicle. Traveling with school transportation or the Special Transport Systems
(STS), both of them being performed partly in cars, was found to be a hazardous
means of transportation. Parents of children with disabilities were mostly worried
6
VTI rapport 489A
about the driver’s lack of knowledge concerning the disability and the needs of
the child. It was concluded that the problem of poor compatibility between the
need for safe road transportation and the use of technical aids and special seating
devices for children with disabilities needs be subjected to future research. In
addition, comprehensive information, focused on the special needs of children
with disabilities in their transportation, would probably reduce the parents’
worries significantly.
VTI rapport 489A
7
Barns säkerhet i bilar – Litteraturöversikt
av Anna Anund, Torbjörn Falkmer, Åsa Forsman, Susanne Gustafsson,
Ylva Matstoms, Gunilla Sörensen, Thomas Turbell and Jan Wenäll
Statens väg och transportforskningsinstitut (VTI)
581 95 Linköping, Sweden
Sammanfattning
Det säkraste sätt att färdas i bil om man är barn det är att åka bakåtvänt.
Det kräver dock att skyddsutrustningen som används är rätt monterad, att
bältet som håller fast barnet är korrekt placerat och barnet inte är placerat
på en plats där det finns krockkudde.
I Sverige och i Storbritannien är användningen av skyddsutrustning för
spädbarn som åker bil, cirka 95 procent. Det innebär dock inte att alla dessa
barn åker säkert – felanvändningen är stor. Vetenskaplig litteratur visar att
ju äldre barnen är desto sämre skyddas de. För barn med funktionshinder är
det långt ifrån en självklarhet att färdas säkert.
Föreliggande litteraturstudie har genomförts med syfte att sammanfatta
kunskapsläget avseende barns säkerhet i bil. Litteraturen har delats in i områdena;
lagar/rekommendationer, olyckor med dödlig/svår personskada, säkerhetskonsekvensen för barn i bil avseende bilutvecklingen speciellt med avseende på
krock kuddar, installationssystem, användning/felanvändning sett ur ett
medicinsk, tekniskt och handhavande perspektiv, åtgärder/kampanjer samt
transportsituationen för barn med funktionshinder.
Litteraturstudien omfattar i huvudsak litteratur om barn i åldern 0–12, vidare
har fokus varit på litteratur skriven från 1990 och fram till idag. Litteratur skriven
på engelska och svenska har ingått och studien begränsar sig till att omfatta
material från Australien, England, USA och Sverige.
I samtliga dessa länder finns det lagar och rekommendationer för hur barn som
åker bil ska skyddas. Kraven relaterar vanligtvis till barnens ålder, vikt eller
längd. Skillnaden i vad som rekommenderas och vad lagen kräver är stor i de
flesta studerade länder. Det finns även stora skillnader i vad som krävs i de olika
länderna. Skillnaderna består t.ex. i kraven på att använda skyddsutrusning för
barn i bil, hur länge en individ betraktas som barn, var i bilen barnen får sitta, etc.
Vid litteraturgenomgången visar det sig att studier baserade på data om
inträffade olyckor med skadade/omkomna barn, uppdelade på ettårsklasser är
mindre vanliga. Detta är en stor brist och viktigt att arbeta vidare med. Kunskap
om omfattningen av antal skadade/omkomna barn som rest i bil är av stor
betydelse, dels för att få en bild av problemets omfattning och orsaken till det,
dels för att veta vilka åtgärder som behöver vidtas och för att kunna avgöra om
vidtagna åtgärder har haft effekt.
Tillgängliga olycksdata visar på en god effekt av t.ex. bakåtvänt åkande.
Djupstudier av olycksdrabbade visar att ett av de största problemen vid inträffade
olyckor var att barnen inte använde bälte. Litteraturen visar att huvudskador var
den vanligaste dödsorsaken för barn i trafikolyckor.
VTI rapport 489A
9
Den näst vanligaste felanvändningen var att små barn vändes till framåtvänt
åkande alltför tidigt. Konsekvensen vid felanvändning i en olycka visade sig vara
störst för spädbarn och de yngsta barnen.
En förklaring till detta är barnets fysiologiska förutsättningar. Den vikt som ett
barns huvud utgör av barnets totala vikt är avsevärt större jämfört med för en
vuxen. Detta innebär att mindre barn alltid behöver särskild skyddsanordning när
de reser i bil.
De skyddsanordningar som finns för barn i bil ska i samtliga länder i Europa
vara godkända enligt ECE R 44/03. Detta testförfarande finns anledning att
utveckla ytterligare t.ex. avseende baksätets styrka och påfrestningar i nacke för
barnen.
Litteraturen visar att utvecklingen av fordonen inte alltid är till fördel för
barnens säkerhet. Flera studier visar t.ex. faran av att placera barn på platser där
det finns krockkuddar. Att placera barn i bakåtvända skydd på passagerarplatsen
fram i fordon utrustade med krockkudde är direkt livshotande i händelse av en
olycka. Dock finns det inte någon studie som påvisar konsekvensen för barn som
sitter på dessa platser i framåtvända skydd. Studier visar att den plats som
fordonstillverkare rekommenderar att placera barnen på är i baksätet. Andra
studier visar dock att det inte är på dessa platser som föräldrarna placerar eller vill
placera barnen. De flesta barn under tre år placeras istället i framsätet.
I Sverige och England färdas nästan 95 procent av spädbarnen och de yngsta
barnen i någon form av skyddsutrustning. Studier visar dock att felanvändningen
var stor, nära 90 procent. Användning en av skyddsutrusning för de något äldre
barnen var avsevärt lägre. Felanvändningen visade sig vara störst i de fall både
skyddsutrustningen och barnen skulle säkras t.ex. som för babyskydden.
I flera studier framkom att föräldrarna trodde att de hade gjort rätt, men att det
visade sig att så inte var fallet. Flera studier visade att föräldrar som själva sökte
efter information hade en lägre felanvändning jämfört med dem som inte sökte
efter information. Studier visade också ett samband mellan felanvändning och
socioekonomiska faktorer. Exempelvis så var hög användning av skyddsutrustning vanligare förekommande för barn i familjer med hög inkomst och hög
utbildningsnivå. Låg användning var vanligare förekommande för barn som kom
från minoritets grupper t.ex. invandrar grupper.
I litteraturen återfinns beskrivningar av åtgärder som vidtagits; dessa är
vanligtvis i form av kampanjer. Det förekom stora variationer avseende om och
hur dessa var utvärderade, varför det är svårt att uttala sig om några resultat från
insatserna.
Uppenbart från studierna av litteraturen är att situationen för barn med
funktionshinder är särskilt bekymmersam. Denna grupp av barn är den mest
sårbara och den grupp som kräver det bästa skyddet. Studierna visar dock att det
förhåller sig precis tvärtom i verkligheten. Barn med funktionshinder skyddas
sämre än andra barn. Detta gäller såväl barn med motoriska funktionshinder som
barn med t.ex. autismspektrumstörningar. Föräldrarna kände en stor oro,
framförallt beroende på att förarna inte upplevdes ha tillräckligt god kunskap om
barnens funktionsnedsättning och vilka behov barnen hade. Det konstateras att ett
sätt att öka säkerheten för barnen kan vara att ha en ökad kompatibilitet mellan
barnens tekniska hjälpmedel t.ex. rullstolar och hur dessa ska kunna nyttjas på ett
säkert sätt i samband med resor i bil/buss. I litteraturen återfinns även andra
förslag på åtgärder t.ex. att öka föräldrarnas och förarnas kunskaper om barn med
10
VTI rapport 489A
funktionshinder och de behov de har. Detta förutsägs även minska föräldrarnas
oro.
VTI rapport 489A
11
Terminology and abbreviations
The following terms and abbreviations are used in the present review. For further
information on terms and abbreviations in the field, but not in this particular
review check also on the NHTSA “Dictionary” web page
http://www.nhtsa.dot.gov/people/injury/childps/csr2001/csrhtml/glossary.html
∆-v: Delta-v, the change of speed during impact.
Accident / Crash: these two terms are used as synonyms throughout the review,
and mainly used the same way as the original authors have used them.
Air Bag: A passive (idle) restraint system that automatically deploys during a
crash to act as a cushion for the occupant. It creates a broad surface on which to
spread the forces of the crash, to reduce head and chest injury. It is considered
“supplementary” to the lap/shoulder belts because it enhances the protection the
belt system offers in frontal crashes. Also known as SRS – supplemental restraint
system; SIR – supplemental inflatable restraint; SIPS – side impact protection
system; IC – inflatable curtain; SIAB – side impact air bag.
AIS: Abbreviated Injury Scale, rating injuries from 1–6 (where 6 is almost always
a fatal injury. For more info see Association for the Advancement of Automotive
Medicine, (1998).
Asperger's syndrome: High functioning autism not in combination with mental
retardation.
ATD: Anthropomorphic test device. Articulated analogue of the body of a human
being, used to simulate a motor vehicle occupant during a crash test, also called
"Dummy". ATDs are not a perfect replica of a human being, but a standardised
measurement equipment making comparable crash tests possible.
Autism: Congenital disability, mainly characterised by qualitative impairment in
reciprocal social interaction, communication and imaginative activity, as well as
by a restricted repertoire of activities and interests, often combined with mental
retardation.
Booster Seats: Are intended to be used as a transition to lap and shoulder belts by
older children who have outgrown convertible seats (over 40 pounds). They are
available in high backs, for use in vehicles with low seat backs or no head
restraints, and no-back; booster bases only. In this review, booster seats are used
as a synonym to booster cushions.
Buckle: The locking mechanism of the vehicle belt and child safety seat
buckle/latchplate system. Buckles are typically mounted/attached to fabric
webbing and/or by metal or plastic stalks.
Car Seat: Common term for a specially designed device that secures a child in a
motor vehicle, meets federal safety standards, and increases child safety in a
crash.
Child Safety Seat/Child Restraint: A crash tested device that is specially
designed to provide infant/child crash protection, abbreviated CRS in this review.
CRS is used as a general term for all sorts of devices including those that are vests
or car beds rather than seats.
Children with Disabilities in this review mainly refers to children with special
transportation needs. This particular group comprise children whose physical,
VTI rapport 489A
13
medical, or behavioural condition makes the use of particular, often speciallydesigned, restraints necessary.
Crash / Accident: these two terms are used as synonyms throughout the review,
and mainly used the same way as the original authors have used them.
CRS: A crash tested device that is specially designed to provide infant/child crash
protection.
EuroNCAP: EuroNCAP (European New Car Assessment Program); A 40 %
offset crash at 64 km/h against a non-solid barrier. The ATD, i.e. the crash test
dummy, is exposed to 40–60 G. The EuroNCAP standard for child safety seats
prescribes front facing positioning of the child.
FMVSS 213: Federal Motor Vehicle Safety Standard that pertains to all restraint
systems intended for use as crash protection in vehicles for children up to
50 pounds.
Forward – Facing Child Restraint: A restraint that is intended for use only in
the forward-facing position for a child at least age one and at least 20 pounds up
to 40 pounds.
Frontal Air Bag: A frontal air bag is one installed in the dashboard.
ISS: Injury Severity Score.
Lap Belt: A safety belt anchored at two points, for use across the occupant's
thighs/hips.
Lap/Shoulder Belt: A safety belt that is anchored at three points and restrains the
occupant at the hips and across the shoulder; also called a “combination belt”.
LATCH: Lower Anchors and Tethers for CHildren (new acronym for
standardized vehicle anchorage system).
MAIS: Maximum Abbreviated Injury Scale, the highest obtained AIS value of a
multiple injury trauma. For more info see Association for the Advancement of
Automotive Medicine, (1998).
National Highway Traffic Safety Administration (NHTSA): The federal
agency that sets performance requirements for motor vehicles and items of motor
vehicle equipment such as child restraints in the USA.
NHTSA: see: National Highway Traffic Safety Administration.
OTC: Optimisation of Travel Capacity.
Passenger– Air Bag: An air bag that is in the right front part of the passenger
compartment. It is larger than the driver bag and would restrain either centre or
right-front occupants. Air bags are a supplement to the use of seat belts and
designed to protect adult occupants in frontal crashes.
Postural support/seat belt: In this review seat belt is used as a synonym for
safety belt, i.e. an assembly of belt and buckles to form an approved occupant
restraint in a car. However, in some publications seat belts are equivalent to
postural supports, i.e. seat components or lengths of webbing used to support a
person in the desired position in a seating system (i.e. to prevent the person from
falling out during normal conditions). A postural support is usually not designed
or intended to provide occupant restraint in a vehicle impact. In this review, a
postural support is denoted as such, not as seat belt.
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VTI rapport 489A
Rearward – Facing Infant Seat: Type of child restraint system that is
specifically meant for use by children from birth up to approximately 20 pounds
used in the rearward-facing mode only.
RSC: Rating system for Serious Consequences.
Safety Belt: The webbing, anchor and buckle system that restrains the occupant
and/or child safety seat in the vehicle. In this review seat belt is used as a
synonym to seat belt.
SBS: Seat Belt Syndrome.
Seat belt/postural support: In this review seat belt is used as a synonym for
safety belt, i.e. an assembly of belt and buckles to form an approved occupant
restraint in a car. However, in some publications seat belts are equivalent to
postural supports, i.e. seat components or lengths of webbing used to support a
person in the desired position in a seating system (i.e. to prevent the person from
falling out during normal conditions). A postural support is usually not designed
or intended to provide occupant restraint in a vehicle impact. In this review, a
postural support is denoted as such, not as seat belt.
Seat Belt: The webbing, anchor and buckle system that restrains the occupant
and/or child safety seat in the vehicle. In this review seat belt is used as a
synonym to safety belt.
Side Impact Air Bags: Provide additional chest protection to adults in many side
crashes. Children who are seated in close proximity to a side air bag may be at
risk of serious or fatal injury if the air bag deploys. Check with the vehicle dealer
or vehicle owner's manual for information about danger to children.
STS: Special Transport Service.
SUV: Sport Utility Vehicle.
Tether Anchor: Attachment point in vehicle for child safety seat tether strap.
Refer to vehicle owner's manual regarding anchor location.
Tether Strap: An additional belt that anchors the child safety seat top to the
vehicle frame; keeps the restraint from tipping forward on impact; can provide an
extra margin of protection. Can be optional or factory installed. A tether strap is
typically available on most child safety seats manufactured after September 1,
1999.
Tiedown: A tiedown can be described as a strap or mechanism that secures a
child safety seat, or a wheelchair in place in a motor vehicle.
Tray Shield: Part of a restraint system in a child safety seat; a wide, padded
surface that swings down in front of the child's body, attached to shoulder straps
and crotch buckle. Looks like a padded armrest, but is an integral part of the
harness system.
T-Shield: Part of a restraint system in a child safety seat; a roughly triangular or
“T” shaped pad that is attached to the shoulder harness straps, fits over the child's
abdomen and hips and buckles between the legs.
Vest: A child restraint system that has shoulder straps, hip straps (and sometimes)
a crotch strap. A vest can be specially made to order according to a child's chest
measurement, etc. Vests must be used along with the vehicle belt system.
VTI rapport 489A
15
1
Introduction
A great many people, among them children, are killed or seriously injured in road
traffic every year, which constitutes a major public health problem (Evans, 1991).
For example, during the years 1994–2000, 186 children below that age of 18 were
fatally injured as car, bus or lorry passengers/drivers in Sweden, based on
compiled statistics from the Swedish National Road Administration (SNRA) for
these years (Sörensen et al., 2003). Considering the rapid progress being made in
developing different road safety measures, new knowledge must be spread more
quickly and be put into application, first and foremost by system designers, but
also by others in positions of responsibility within the road safety sector. One fast
and cost-effective means of finding out where research stands today is to
systematically review, analyse and make a compilation of the scientific literature
published in the field. The present literature review was made for this reason.
1.1
Children in traffic and the “Vision Zero”
Automobile travel is a part of everyday life that begins in early infancy. Journeys
to and from kindergarten, school and leisure activities become more frequent the
older the child gets. Hence, children are frequent users of the road transport
system and are thus exposed to the inherent risks associated with motor vehicle
transportation.
During 1995, a goal – the “Vision Zero” - was set up in Sweden (SNRA,
1996). Similar goals of different target levels exist in many countries. The "Vision
Zero" is based on attaining a level of zero fatalities and no serious health losses in
the traffic system. A basic assumption in the "Vision Zero" is that the transport
system should be designed to suit the least tolerant person using the system. Such
a person should be taken as the design person for the system. The design of the
road transport system, based on human tolerance, demands the most detailed
knowledge of injury mechanisms and tolerance ability. Thus, one of the
challenges is to identify such a design person for this system. Taking the “Vision
Zero” seriously means that a person with low tolerance to mechanical forces (e.g.
a child) should be the design criterion for the road transport system.
1.2
Child anatomy
Children in general are exposed to increased risks of fatalities and serious health
losses in the traffic system owing to several factors (Evans, 1991), one of these
being their anatomy. As shown in Figure 1, children differ from adults not only in
size but also in body segment proportions and anatomy (Tingvall, 1987).
16
VTI rapport 489A
Figure 1 Proportion of the human body in relation to different ages. From left to
right: newborn infant, 2-year old child, 6 year old child, 12 year old child and 25
year old adult (Hove, Christensen and Poulsen, 1982)
The average weight of a child varies from 3.5 kg at birth to 35 kg at the age of 10.
The average height varies between 50 cm and 140 cm during the same period. The
length of the head of a newborn child is one quarter of the total body length,
whereas in an adult the corresponding ratio is 1 to 7.
The size and shape of the skull and the chest of an infant differ from those of an
adult. Young children are exceptionally vulnerable (Baker, 1979; Evans, 1991)
because their heads are large in relation to their body size. This means that there is
a comparatively larger weight supported by a fairly thin neck. The potential for
neck injuries in general is greater (Shaw, 1987). Also, the skeleton is less well
developed, with lower ability to absorb and spread the energy transferred to it.
Figure 2 Proportion of the human body in relation to different ages. From left to
right: newborn infant, 2-year old child, 6 year old child, 12 year old child and 25
year old adult (Hove, Christensen and Poulsen, 1982).
Hence, ribs will bend rather than break, resulting in collision energy being
transferred to the heart and lungs. The spine’s bony links are less well developed,
which allows additional movement that can place undue stresses on the ligaments
supporting the spine and, thus, lead to spinal damage. The abdomen is also
different, in the sense that a smaller part is covered by the pelvis and rib cage in a
child than in an adult. There is also a difference between the child and adult
pelvis, in that the anterior superior iliac spine, shown in figure 3, which is
important for the use of a lap belt, is absent up to the age of 10 (Tingvall, 1987).
VTI rapport 489A
17
Figure 3 Arrow indicates anterior superior iliac spine in an adult person and its
relation to a correctly applied lap belt. The illustration is from Wevers (1983).
The differences in body segment proportions are also reflected by a higher centre
of gravity in the child, which may affect the body kinematics in the event of an
accident. The tolerance of a child's body to high forces also differs from that of
adults. The injury pattern among children is quite different from the injury pattern
in adults. In the former, injuries to the head are common and those in other parts
of the body are relatively rare, whereas in adults the reverse pattern is found.
Safety data for children demonstrate that a child is exposed to extremely high
forces in a vehicle collision (Shaw, 1987). These forces can throw the child
against the often sharp edges in the vehicle's interior and possibly eject the child
through a window, open door, or windshield. Only properly designed and
carefully used restraints can distribute collision forces in a non-injurious manner.
Thus, safety restraints must be capable of withstanding these extreme forces and
distributing them over the child's body to prevent injury (Shaw, 1987). Because a
child’s physical structure is different from that of an adult, safety restraints must
be designed differently for children. The shoulders and pelvis are the main points
bearing the safety belt loading and these points are less well developed in the
child, thus they are offering less protection. Nevertheless, Gammon (1995) argued
that the effect of having a proper restraint for children was to reduce the number
of serious injuries by 40–70 % and the number of fatalities by 50–100 %. These
figures indicate that it is essential for a child’s safety to use safety restraints and,
in adequate cases, in combination with child safety seats during road vehicle
transportation.
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VTI rapport 489A
2
The aim of the study and its limitations
In order to study child safety in cars, international literature was reviewed with
respect to road vehicle transportation for the target group (0–12 years). The
review only includes literature in English and Swedish. Furthermore, the review
was limited to focus on results from Australia, the U.K., the USA and Sweden.
In Sweden, children are legally defined as persons younger than 18
(Socialdepartementet, 1981). Despite this fact, the focus is on children in age
0–12 years old, mainly due to the fact that from a safety perspective most children
older than 12 have more similarities with adults than with smaller children with
respect to anatomy. However, in case reviewed studies also included results about
children older than 12, we have chosen to include these results, as well.
Children are different and we need to account for these differences. The most
vulnerable sub group of children is probably children with disabilities (Falkmer,
2001). Thus we have included the transport safety situation in road vehicles and
its consequences for children with disabilities in the review. For this particular
group of children, the review focuses on children up to the age of 18, due to the
fact that the variance in anatomy is larger than for other children (Falkmer, 2001).
To make sure that all children are protected as passenger in car, several aspects
need to be considered. Within this study we have chosen to focus on legal aspects
and recommendations, traffic fatalities and serious injuries, the safety
consequences for children due to the car development, installation systems, use
and misuse regarding medical, technical and user aspects, and, finally,
measurements for improvement, e.g. campaigns.
VTI rapport 489A
19
3
Method
The search has been made by VTI Library and Information Centre (BIC). BIC
collects, organises, stores and disseminates information in the field of transport
and communication research. The review focused on road vehicle transportation
and was based on international literature indexed in the Mobility (SAE), MIRA,
Compendex MedLine, ITRD, TRAX, TRIS and Internet.
The following topics were covered: Regulations and standards, children in
traffic and the “Vision Zero”, child anatomy, rearward facing, forward facing,
child restraint systems, children with disabilities and transportation safety
equipment, travel habits, transport providers, transport procedures, and perceived
risks and safety problems according to parents and drivers, improvements, counter
measures campaigns, children and airbags, children and accidents, children and
legislation, children and misconceptions, injuries and child safety devices.
The review concerned literature mostly from 1990 to the present.
Exceptionally, we have also included some relevant documents of major
importance older than this. However, no literature dated earlier than 1980 was
reviewed with respect to children with disabilities. The reason for choosing this
cut-off point was that the development of child safety seats and vehicle safety
during the last twenty years has been so rapid that literature from 1979 or earlier
was found to be less relevant.
In the literature review, we have also included searches on the World Wide
Web (www). Assumptions regarding e.g. laws and recommendations consist of
facts that change over time. The most updated version probably will be found on
the web.
There are no general definitions of use and misuse of restraints. In some
literature the concepts are used to describe use and misuse of seatbelts, in others it
describes the use and misuse of Child Restraint System (CRS), and in others both
seatbelts and child restraints are included. Moreover, the concept of misuse is
ambiguous. The term misuse can include one, or a combination of several, of the
following aspects:
• Length-inappropriate CRS according to the law
• Age-inappropriate CRS according to the law
• Weight-inappropriate CRS according to the law
• Length-inappropriate CRS according to the recommendations
• Age-inappropriate CRS according to the recommendations
• Weight-inappropriate CRS according to the recommendations
• Appropriate CRS not correct mounted
• Appropriate CRS not correct used, e.g. incorrect belt positioning
Furthermore, the difference between non-use and misuse is vague.
When we discuss about the above presented aspects we have used following
structure:
• The parents/adults firstly need to decide on whether or not to utilise any
type of safety belt and CRS.
• Secondly, if they chosen to use safety belts and CRS they have to chose a
CRS according to the child’s length, weight and age.
• Thirdly they need to mount the CRS.
• Fourthly, they have to seat the child in the CRS.
20
VTI rapport 489A
• Finally, they need to fit the safety belts and internal safety devices of the
CRS.
In each of the above steps there is a question of doing it or not, and if doing it,
doing it correctly or incorrectly. We have in this review chosen to refer to use or
not, and misuse or not.
• Depending on the child’s different ages, the need for CRS and safety belt
varies. This means that at a certain age the need for CRS plus safety belt
disappears and the child is both legally and safely as well protected as possible
with the safety belt only. This means that when we refer to use and misuse it is
relative to the age adequate CRS. However, this becomes somewhat altered
with respect to children with disabilities, as many of them travel seated in the
technical aids. For this reason, the transport mobility situation for children with
disabilities is presented separately.
Since the authors of the reviewed literature seldom define what is meant by the
used terms such as “misuse”, it is difficult, if not impossible, to be sure how to
correctly interpret the literature.
VTI rapport 489A
21
4
Results
4.1
Legal aspects
When trying to understand questions about e.g. misconceptions, misuse,
campaigns concerning child safety in vehicles, it is important to keep in mind that
there are different laws and recommendation in each country. This chapter mainly
deals with what the law demands.
In all of the referred countries there are regulations about the technical
construction of the CRS. Every child safety seat on the European market has to be
approved and/or labelled according to ECE R. 44/03. In the USA it is called
FMVSS and in Australia it is called Australia Standard 1754.
In most of the countries it is against the law for two passengers, even two
children, to use the same seat belt.
There are a lot of websites with available information. One of the most
comprehensive is the website from Royal Society for the Prevention of Accidents
(Child Car Seats: types of child seats, 2002).
Table 1 presents an example of information from this website (March 2003)
concerning existing laws in some countries.
Table 1 Existing laws and regulations in different countries.
Australia
Sweden
U.K.
USA:New York
22
Children under 1 year old must be restrained in a suitable
approved child restraint. Children aged 1 to 15 years must be
restrained in a suitable approved child restraint, or occupy a
seating position fitted with a suitable seatbelt if one is
available.
If the vehicle has 2 or more rows of seats, the child must not
be in the front row of seats unless restrained in a suitable
approved child restraint or occupying a seating position fitted
with a seatbelt. Australian child restraints must be fitted with
a top tether which is attached to a suitable mounting point on
the vehicle. The use of European child restraints without a top
tether is, therefore, illegal.
Children are permitted to travel in the front seat, although use
of an approved child restraint is mandatory overall until the
age of 6 years.
It is forbidden to use a rear facing child safety seat in the front
seat in a car that has a passenger front/side airbag.
Children travelling in cars have to use a CRS or seat belt, if
they are available. Children cannot be carried in the front seat
unless they are either in a child restraint or are using the seat
belt. It is the driver's responsibility to ensure that children
under the age of 14 years are either using an appropriate child
restraint or a seat belt if available.
Children aged 3 years and younger must be in a child
restraint.
4 to 15 year olds must be restrained but can use the seat belt if
no child restraint available.
VTI rapport 489A
USA: Florida
USA: California
USA: Michigan
Children aged 3 years and younger must be in a child
restraint.
The seat belt can be used (if restraint unavailable) for 4 & 5
year olds who also must be restrained.
Children must be secured in an appropriate child passenger
restraint until they are at least 6 years old or weigh at least 60
lbs. Children weighing more than 40 lbs may be belted
without a booster seat if they are seated in the rear seat of a
vehicle not equipped with lap/shoulder belts.
Children aged 6 to 15 years or children weighing 60 lbs or
more must be restrained but the seat belt can be used.
Children aged 3 years and younger must be in a child
restraint.
The law described on this web site is a summary and written in an easy language.
We have looked more in detail for a selection of countries, i.e. Australia, the U.K.,
the USA and Sweden
4.1.1 Australia
All six States have regulations requiring children up to 1 year of age to be
restrained in an infant restraint or child seat, if the vehicle is fitted with child
restraint anchorages. Children older than 12 months up to the age of 14 years are
required to use a child restraint system or a regular seat belt, if one is available. If
a restraint is not available, the child must not ride in the seating compartment.
All child restraints are required to conform to Australia Standard 1754 and
must be used in accordance with the manufacturer's specifications. Booster
cushions are allowed in any seating position fitted with 3 point seat belt. All other
child restraint systems must be used in a rearward seating position.
Also for Australia there are several websites providing information about
legislation for children as passengers. Child and Youth Health (2003) have
summarised the legislation and some recommendations for parents. Child and
Youth Health is an independent State Government health unit, funded primarily
by the Department of Human Services.
The driver is responsible for children under 16 years wearing their seat belt, or
being strapped into a restraint. It is against the law for two passengers, even two
children, to use the same seat belt. The law does not say that children cannot ride
in the front seat of a car, provided they are using proper restraints; however the
front passenger seat is the least safe seat in the car and provides less protection for
the passenger than any other seat.
Also in Australia there are differences between what the law requires and the
recommendations. The recommendation for infants is that they should travel
rearward facing when weighing less than 9 kg. Booster seats are recommended to
be used after a child grows out of the car seat (at approx. 18 kg or 4 years of age)
but may be used from 14 kilograms.
4.1.2
U.K.
The law requires children in Great Britain travelling in cars to use an appropriate
child restraint or a seat belt, if such restraints are available. Children are not
VTI rapport 489A
23
allowed to be carried in the front seat unless they are either in a CRS, or using the
seat belt. It is the driver's responsibility to ensure that children under the age of 14
are either using an appropriate CRS or a seat belt, if available. If carried in the
front seat, an appropriate CRS must be used for children younger than three (the
seat belt is not sufficient). If carried in the rear seat, an appropriate CRS must be
used, if available. If an appropriate restraint is fitted in the front seat of the car,
but not the rear, children younger than 3 years old must sit in the front and use
that restraint.
Children aged 3 to 11 years and shorter than 1.5 metres must, if carried in the
front seat, wear an appropriate child restraint, if available. If not, a seat belt must
be used. If carried in the rear seat, an appropriate child restraint must be used if
available. If not, a seat belt must be used if available. If an appropriate restraint or
seat belt is fitted in the front seat of the car, but not in the rear seat, children
between 3 and 11 years old and shorter than 1.5 metres must use that restraint or
seat belt.
New child restraints must conform to ECE R.44/03, but child restraints that
conform to a British Standard or to an earlier version of ECE R.44 may be used.
4.1.3
USA
The National Highway Traffic Safety Administration (NHTSA, March 2003) has
summarised the safety laws for children. All 50 states of the USA have child
passenger safety laws ("car seat laws"). NHTSA has pointed out components that
are essential for a strong child restraint law i.e. to:
• cover all occupants up to age 16 in all seating positions
• require child occupants to be properly restrained.
• include all vehicles equipped with safety belts.
• make the driver responsible for restraint use by all children younger than 16.
• allow passengers to ride only in seating areas equipped with safety belts.
• prohibit all passengers from riding in the cargo areas of pickup trucks.
More details can be found at the NHTSA website.
In May 1995, the National Highway Traffic Safety Administration (NHTSA)
issued a final rule allowing manufacturers to install an on-off switch for the
passenger air bag in vehicles that cannot accommodate a rearward-facing child
seat anywhere except in the front seat, e.g., pickup trucks and cars with no rear
seat or with small rear seats (Morgan, 2001).
In November 1997, NHTSA issued another final rule defining high-risk groups
that should not be exposed to passenger air bags: infants, children 12 years old
and younger, and adults with certain medical conditions. The rule enables owners
of any car, pickup truck, van, or sport utility vehicle to obtain an on-off switch for
their passenger air bag if they transport people in one of these high-risk groups.
In a study presented by the National Safety Council (2002) they argue that
primary laws benefit children's safety compared with secondary laws. The reason
is that if the adults use the seat belt they also will make sure that their children do.
The primary laws allow the police to stop and ticket drivers for not using seat
belts. States that actively enforce their laws have achieved increased seat belt
usage, which in turn has an implication for increased child safety.
24
VTI rapport 489A
4.1.4
Sweden
The Swedish law (SFS 1998:1276 kap 4, §10) states that children up to and
including the year they turn six, have to use an appropriate child restraint when
travelling in a car. Apart from that, both adults and children travelling in a car are
restricted to be positioned on a seat that is equipped with a seat belt if there is one
available. Seat belt usage is mandatory for those seats equipped with them.
According to the law it is the driver's responsibility to make sure that all
passengers younger than 15 are restrained during the ride. Furthermore, rearwardfacing child restraints are not allowed in the front seat if an airbag is fitted. New
child restraints must conform to ECE R.44/03, but child restraints that conform to
a T-godkännande or to an earlier version of ECE R.44 may be used.
To further improve the safety of children, the National Society for Road Safety
(NTF, March 2003) and other traffic safety organisations provide
recommendations regarding child occupant safety. Swedish parents are
recommended to let the children travel rearward-facing as long as possible, at
least until the child is four years' old. Rearward-facing infant seats are
recommended for children younger than a year and shorter than 70 cm/weighing
below 10 kilograms. Rearward-facing child seats are recommended for children
from the age of 6–12 months up to 4–5 years. When they have outgrown the
rearward-facing child restraints available on the market, children are
recommended to use booster seats or booster cushions. Children shorter than
140 cm are recommended not to sit in the front seat if an airbag is fitted.
4.2
Traffic fatalities and
international scene
serious
injuries
on
the
It could be useful to make statistical comparisons between different countries. For
children, however, the availability of data is less than could be desired. This is
definitely the case when we look at exposure data. To make good comparisons
between data from different countries we need to know not only the number of
accidents and the size of the population, but we also need to know traffic exposure
data. The travel patterns are likely to vary between different countries. Children
are often treated as one group, even though there are societal preconditions that
affect the travel patterns. A few examples that affect the travel patterns between
different countries are:
• Length of maternity leave
• Proportion of children in day care/kindergarten
• Age at school start and average distance to school
The availability of statistics varies between different countries in more than one
aspect. In Appendix 2 some available sources are attached. One-year groups are
readily available for fatalities and seriously injured only in Great Britain.
Although not published as one year groups, the same statistics are available upon
request in Sweden. Australia has published data as one-year groups for fatalities
only. This study covers only published data and in some cases it is possible that
one-year data is available upon request. In the USA all accident reports are
available with the exact ages of victims. The population data is, however, not
published as one year groups.
For most countries there are too limited amount of data to draw any definite
conclusions from one single year. For example, during the year 2000, 63 children
VTI rapport 489A
25
in Australia were killed as passengers in cars. The corresponding number in the
U.K. was 37, in the USA 1,126 and in Sweden 8 children. Due to this the
conclusions drawn from Figure 4 should not generalised but it could give an idea
of the extent of the problem.
As an example, traffic fatalities in cars from the year 2000 are used, see Figure
4. For each observation the number of fatalities is divided by the total number of
children per country of that particular age. No exposure data is used.
Killed/100000 children year 2000
4,5
UK
4
Sweden
3,5
A ustralia
3
USA
2,5
2
1,5
1
0,5
0
0
2
4
6
8
10
12
14
Age [ye ars ]
Figure 4 A comparison of fatalities for car passengers (aged 0–12) between The
U.K., Sweden, Australia and the USA., data from year 2000.
From Figure 3 we can notice that there are great differences between the countries
as well as between the age groups.
Instead of a comparison of fatalities it could be of interest to compare the
serious injuries, see Figure 5. The exact definition of injury is not known for all
countries. For Sweden and UK all reported injuries are included. The number of
injured children of a certain age has been divided by the total number of children
of the same age.
180
Injured/100000 children
160
UK
Sw eden
140
120
100
80
60
40
20
0
0
2
4
6
8
10
12
14
Age [ye ars ]
Figure 5 Comparison of injured car passenger (aged 0–14) between the U.K. and
Sweden, data from year 2000.
26
VTI rapport 489A
Even from this small example it is obvious that correct evaluation of these
statistics requires in-depth knowledge of both child restraint systems and the way
they are used in other countries, and of course, to what extent they are used.
During the review we have not found any literature focusing on one-year group’s
statistics for fatalities and seriously injured children in car.
4.3
Car development, installation systems and its
implications for child safety
4.3.1
Car development
The introduction of passenger side airbags in vehicles has direct implications for
child safety and the question of where to place the child. Airbags are installed in
order to protect adults in case of a crash. However, children who are exposed to
airbag deployment may be seriously injured or killed (Turbell, Lowne, Lundell &
Tingvall, 1993; Weber, Dalmotas & Hendrick, 1993; Weber, 2000; Ziernicki,
Finocchiaro, Hamernik & Fenton, 1997). Children in rearward facing child
restraint are in particular danger since they are very close to the airbag housing. If
a deploying airbag hits the child restraint while still inflating, the force will be
considerable and the child could be fatally injured (Weber, 2000). Even children
in forward-facing restraints could be at risk and the recommendation from the
Swedish National Road Administration (SNRA) is to never let a person shorter
than 140 cm ride in a seat equipped with an airbag (Vägverket, 2003). In the USA,
a total of 135 cases of children killed by deploying airbags have been reported up
to the year 2002 (NHTSA, 2003). Most of these children, 101, where not properly
restrained or were not restrained at all, while 22 of them were placed in rearward
facing child restraints. As of May 2001, no such deaths have been reported in
Sweden (Socialstyrelsen, 2001).
The described conflict between children and airbags initiated a survey of how
this conflict is treated by manufacturers and importers of cars in Sweden
(Forsman, Hellsten & Falkmer, 2003). A questionnaire was sent to Swedish
general agents and included questions of availability and placement of airbags in
different vehicles, recommendations on where to place different types of child
restraints and if and how the passenger side airbag could be deactivated. A total of
62 models from 23 different car manufacturers were included in the survey and
they were all among the 71 most sold cars in Sweden during January to September
2002. The results showed that passenger side airbags were available in all but one
model, either as standard (53 models) or as supplementary equipment (8 models).
The recommendation from most of the general agents was to place children in the
seat; although the centre rear seat position was only recommended if equipped
with a 3-point belt. This recommendation is not undisputed; the SNRA are of the
opinion that it can be advantageous to place small children in the front passenger
seat if the driver and the child are alone in the car. In addition, the Swedish
insurance company Folksam states that the front passenger seat is the best place
for the type of rearward-facing child restraints that rests against the dashboard.
This statement is based on results from their research division which shows that
the dashboard provides a relatively gentle braking of the child restraint (Folksam,
2003).
If a child is placed in the front passenger seat, the airbag must somehow be
deactivated. At present, there are no statutes in Sweden that regulate deactivation
VTI rapport 489A
27
of passenger side airbags, and results from the study by Forsman et al. (2003)
show that different car manufacturers offer different solutions. Some vehicle
models have an on-off switch that makes it possible to temporarily deactivate the
airbag when a child is using the seat. For other models it is possible to
permanently deactivate the airbag at a repair shop or to order the vehicle without a
passenger airbag. However, there are models for which it is not possible to
deactivate the passenger airbag. The National Road and Transport Research
Institute (VTI), Folksam and the National Society for Road Safety (NTF) have a
joint policy which states that the responsibility for deactivating the airbag should
not be placed on the driver, parent or other non-authorised person by allowing
installation of an on-off switch (VTI, Folksam Forskning & NTF, 2003). The
SNRA also recommends permanent deactivation of the passenger airbag if
children are to be transported on the seat in question. In the U.S., driver and
passenger side airbags are mandatory since September 1, 1997 (U.S. Department
of Transportation & NHTSA, 1993) and deactivation is strictly regulated (U.S.
Department of Transportation & NHTSA, 1997). Permanent deactivation is never
allowed and on-off switches can be installed only in exceptional cases. Such a
case can be if children under the age of 13 for some reason must be transported in
the front passenger seat. The U.S. standpoint is based on the opinion that adult
passengers should always be protected by an airbag when seated in the front. A
study of possible misuse of on-off switches has recently been conducted in four
states, California, Georgia, Michigan, and Texas (Morgan, 2001). The study
included late model pickup trucks equipped with a passenger side airbag and an
on-off switch. A total of 1,637 vehicles were investigated, 1,117 of them had an
adult as passenger and 520 had a child on the passenger seat (23 infants). In
vehicles with an adult passenger 18 per cent incorrectly rode in front of a
deactivated airbag and in vehicles with a child passenger 46 per cent rode in front
of an activated airbag. However, of the 23 infants only 2 did sit in front of an
activated airbag.
According to the Department of Transport and Regional Services the conflict
between children and airbags does not exist in Australia (DOTARS, 2003). The
child restraints used in Australia include a top tether strap which is attached to an
anchorage point in the vehicle. Such anchorage points can only be mounted in the
rear seat of the vehicle and accordingly, all children using child restraints are
transported in the rear seat. Moreover, the Australian airbags inflate with less
force and have larger vents than U.S. airbags. This makes them “softer” which
decrease the injury risk for small adults and children who no longer use child
restraints.
The European consumer organization, ANEC, has awarded a contract to one of
the leading suppliers of automotive engineering and testing services to look at rear
seat back strength. For many years, consumer groups have been arguing for
improved strength of the rear seat back in cars. Accidents show that luggage in the
rear seat can load the rear seat back in case of a frontal collision and cause the seat
back to deform heavily or fail altogether, exposing the rear seat occupants to
additional loading. Such additional loading can cause restrained rear occupants,
both adults and children, needless injury. Split folding rear seats, because of their
current design, are especially liable to provide poor luggage restraint. The
situation has increased importance now, when many manufacturers are relying on
the rear seat to carry loads from the top tethers of a new generation of child
restraints. Such loads add to the existing loads imposed by luggage and the seat’s
28
VTI rapport 489A
own inertia in a frontal impact. On the basis of the test results of the ANEC
research project, the organisation will make recommendations for improving the
international regulations on testing rear seat back strength. The results of the
ANEC study can also be used to contribute to discussions regarding luggage
retention requirements in the new car assessment programme, EuroNCAP.
4.3.2
Installation systems
In the late 1980s, a working group of ISO (the International Standardisation
Organisation) was formed, with the mission to achieve international
harmonisation and standardisation of child safety in cars (Lundell, Claesson &
Turbell, 1993). One of the aims was to reduce misuse and non-usage of different
types of CRS, by simplified and standardized methods for usage. In the early
1990's, the initial development of a number of standardized anchorage devices to
be mounted in cars for the CRS began; i.e. the so called ISOFIX standard. The
CRS is supposed to be easily attached to these anchorage devices. A couple of the
first prototypes are described in Turbell, Lowne, Lundell & Tingvall (1993). The
ISOFIX standard system work was completed in 1999 (Weber, 2000) and ISOFIX
systems are now mounted in more than 15 million cars world wide. However,
CRS designated for the ISOFIX systems have, so far, only been subjected to
official approvals when mounted in a certain vehicle and, hence, an approval has
been given only together with a certain car model, according to the European
directive ECE R. 44/03. There is a suggestion for a change in the directive so that
CRS could be approved on a general level utilising the ISOFIX systems, but at
present the timing for such a change is not settled.
In the USA, a system called LATCH (Lower Anchors and Tethers for
Children) has been developed. It is based on the ISOFIX system but with certain
modifications. The ISOFIX system has two lower anchor points between the
horizontal part of the seat and the backrest. The LATCH system also includes a
high mounted anchor point for forward facing CRS. The LATCH system is
mandatory in all cars manufactured and sold after September 1st 2002 in the USA
(FMVSS 213, 2003)
EuroNCAP, (2003) the European car crash test programme, has tried to
introduce a new protocol to look at how the car manufacturer protects a 6 month
old and a 3 year old child. The introduction of child protection in the scheme's star
rating is so far not implemented.
4.4
Data from accidents and crash tests regarding child
safety seats.
Back in 1974 the VTI did a series of tests where frontal impact performance of
CRS was studied (Turbell, 1974). This study, although it might look old, seems to
be a kind of milestone in the Swedish tradition about rearward facing child
restraints. It is of historical interest and the results are also still valid. It is also the
main source for the Swedish tradition of so eagerly supporting the rearward facing
CRS and also a very important factor as to why there are no modern supporting
crash tests. Rearward-facing systems, integral forward-facing systems, booster
seats, booster cushions, shields, harness and lap belts were tested. Rearwardfacing systems in the back seat had nearly as favourable values, but due to a
somewhat softer frontal support than in the front seat, there was a slight slack
inducing some Gz-components in the range of twice those of rearward-facing seats
VTI rapport 489A
29
in the front seat of the car. Forward-facing CRS and belts with upper torso straps
show a completely different deceleration pulse, with mainly late and high Gzcomponents, induced by the head being decelerated by tension forces in the neck.
The tension and the Gz, are at least three times those of the rearward-facing
systems and the additional angular acceleration is also high. The study showed a
significant advantage for rearward-facing CRS in relation to forward-facing CRS
of all types. There was also a significant advantage of rearward-facing CRS in the
front seat in comparison with rearward-facing CRS in the back seat. Harnesses
and shields showed potential for both submarining and late but strong rebound
deceleration.
One of the most frequently referred studies is by Tingvall (1987). Injuries to
children (0–14 years of age), during 1976–1983, were compared to injuries to
adult car occupants. The conclusion was that fatal injuries to children were mainly
located to the head, whereas this is not the case for adults. About 72 % of fatally
injured children had head injuries and for the adults the same figure was 56 %,
whereas adult chest injuries were higher than for children. The same pattern was
observed for non-fatal injuries, where adults showed a higher exposure to upper
and lower extremities soft tissue injuries and fractures, as well as to thorax
fractures. The author also described a strong correlation between the risk of injury
and the type of restraint that was used. Out of a selection of about 80,000 cases
reported to an insurance company, 2,763 children where involved in car accidents,
and among those about 295 were reported with injury in various degrees. Injuries
were coded according to the AIS (Abbreviated Injury Scale), the ISS (Injury
Severity Score) and the RSC (Rating system for Serious Consequences). The
effectiveness of different restraints was estimated. Among the injured children
1.2 % had used a rearward-facing CRS and 6.9 % had used a forward-facing CRS.
Among children wearing only a seatbelt 8.9 % were injured. Unrestrained
children represented 15.6 % of the children with injuries. The study also found
that the injuries of restrained children were less severe than those of unrestrained
children. Various data concerning protection effectiveness is derived from this
study. One of the most used is that rearward-facing CRS has an effectiveness of
90.4 % (±11.2 %, 5 % level). One of the conclusions is also that CRS are effective
in all collision directions.
A study by Carlsson, Norin & Ysander (1991) was based on about 13,000
Volvo car accidents that occurred between 1976 and 1988. In those crashes,
approximately 22,000 persons were involved in various degrees, not all of them
injured. We have to keep in mind that during this period the rear seat seatbelt
became mandatory in 1986. Furthermore, that mandatory seatbelt use and
requirements for approved CRS did not apply to children until 1988. About 1,500
of these crashes involved at least one child 0-14 years old. Among those children,
142 were restrained in rearward facing CRS, 130 in forward facing CRS, and an
additional 228 children were unrestrained. (the "unrestrained children” group
comprises all other modes of travel, e.g. unrestrained in normal seating positions,
sitting on an adult’s lap, lying or standing in the car.) The level of
misuse/incorrect installation among those children was determined by interview
studies and classed as partial misuse when the child was not properly restrained or
had the wrong size. The wording “Gross misuse” is defined in the report as
meaning incorrect mounting or no mounting of the child seat, or the child not
being restrained in the seat. Of the 142 rearward facing child seats, 9 (6 %) were
used incorrectly. The most common misuse was that the seat was not fitted
30
VTI rapport 489A
according to the instructions. In two cases the child seat was fitted facing forwards
instead of properly rearward facing. Studying Maximum Abbreviated Injury Scale
(MAIS) 2–6 values gives a 92 % injury reducing effect on rearward-facing CRS
and 60 % injury reducing effect on forward-facing CRS/booster cushion/seat.
When investigating the fatality risk among children younger than 12 years' old,
Braver, Whitfield & Ferguson (1997) compared front- and rear seated passengers
involved in fatal crashes. For forward-facing children in the back seat, either in
booster seats/cushion or using the seat belt, a 35–50 % reduction of fatality risk
was found compared with children placed in a rearward-facing seat in the front
seat. Although interesting, data is explicit noted as statistically not significant and
also technically mainly due to the extended risk with passenger side airbags. A
10–20 % lower risk of fatality was noticed on the rear centre seat compared with
rear outboard positions.
Arbogast, Cornejo, Kallan, Winston & Durbin (2002) have investigated
specific injuries to children in forward-facing CRS. Out of 25,774 accidents, a
sample selection was subjected to further survey investigation. Completed survey
data was obtained for 1,722 children in the age group 12–47 months. The selected
children were seated in forward-facing CRS. Most children (98.5 %) were seated
in a rear seat. About 48.3 % were involved in a frontal collision, and 43 of the
children (0.17 %) placed in forward facing child restraint were recorded as
seriously injured. About 19 % of the children sustained head injuries, both as a
result of contact induced injuries and internal injuries. Head and neck injuries
were identified as the main cause of impairment and/or death. The author’s
conclusions were that the occurrence of head and neck injuries for these children
provides supporting data to suggest that an extension of the current
recommendation to keep children rearward facing beyond 1 year of age may be
appropriate. In this configuration, the CRS shell itself provides restraint and
protection for the neck, as the forces are transferred to the entire torso of the child.
This result is supported by data from Sweden (Isaksson-Hellman, Jakobsson,
Gustafsson & Norin, 1997), which shows that keeping children rearward facing
up to age three or four years reduces all types of serious injuries, not just those to
the head and neck. The authors also stated that the CRS is part of a system, the
car, the belt system and the CRS itself. The effectiveness of the CRS is often
reduced by large intrusion into the passenger compartment in the event of a crash.
In a report from NTSB (National Transportation Safety Board, 1996) accidents
with inappropriate restraint systems were investigated. Overall, the data showed
small differences in injury severity for children in inappropriate restraints (n =
133) compared with those in the appropriate restraints (n = 51). In total, 32 of the
51 children in appropriate restraints sustained no or minor injury compared with
92 of the 133 children in inappropriate restraints. Five children who were in
appropriate restraints and ten children who were not in appropriate restraints were
fatally injured. However, when the data were examined by accident severity,
differences appeared. The children in low to moderate severity accidents who
were in appropriate restraints sustained less serious injuries than children in
inappropriate restraints; six children in low to moderate severity accidents and
who were not in the appropriate restraint system were fatally injured. Even when
child restraint systems were used improperly, they still provided some level of
protection to the child. Of the 26 children in improperly used child restraint
systems, 14 sustained either no or minor injury. In this American study mainly
forward-facing systems were used and the typical incorrect use of the CRS was
VTI rapport 489A
31
mainly too loose fit of belt systems or belt systems adjusted too high over the hip
or shoulder. A couple of shoulder straps behind the back were also recorded.
An in-depth study of car crashes in Australia in which child occupants were
injured (Henderson, 1994) confirmed the effectiveness of child restraints and seat
belts in protecting children. The vast majority of children in the study who were
restrained in child restraints suffered only minor injury. Many survived very highspeed crashes without injury to the neck or other parts. A far higher proportion of
those unrestrained were seriously injured.
Wenäll (2001) analysed 70 fatal accidents that occurred during 1992–1997. In
these accidents 79 children were killed. Among those 79 children only nine
children were seated in a rearward-facing CRS, all except one were subjected to
impact by heavy vehicles. One accident was a side collision with another car at
high speed. All of these nine accidents recorded large occupant compartment
intrusion or complete structural collapse. Twenty children were not restrained at
all, nine were incorrectly restrained. More than 80 % of fatal injuries were injuries
to the head and neck region. The author's prediction was that 25 of the 79 children
would have had a fair chance of survival if proper restraints had been used in the
way intended.
Tingvall (1987) made a comparative study in which common CRS
misconceptions, found in real life, were subjected to a controlled crash test. The
most common actual erroneous installations were chosen and reconstructed in five
different tests. The most frequent misconception for forward-facing systems was
improper use of belt guides. For rearward-facing systems the two most common
misconceptions were that the CRS was not correctly attached to the car anchor
points, or that the CRS was actually installed forward-facing. The tests showed
that poor protection was provided by the incorrectly installed CRS, the most
frequent consequences were variations of submarining of the ATD (i.e. the “crash
test dummy”).
In a study by Gotschall et al. (1997), 121 restrained children who where injured
in 97 car crashes were studied. The typical crash was a frontal collision with a
difference in speed caused by the retardation in the crash (∆-v) of 36.3 km/h
(± 15.5 km/h). The head and face of the children were the most frequently injured
body regions; more than 60 % of the injuries were to one of these body regions.
Nearly all injuries to the head, spine, and chest were moderate (AIS 2) or severe
(AIS 4). Restraint misuse was found for 84 % of the children. Incorrectly
restrained children experienced a higher mean Injury Severity Score (ISS) than
correctly restrained children (12.3 vs. 7.1) and incurred medical charges more
than 2 times higher (US $36.839 vs. US $15.004).
A Canadian study (Howard, 2001) discussed the risk of child car occupant
ejection in rollover crashes. In case studies it was noted that the risk of ejection
seemed to be higher in forward-facing CRS with T-shields (Part of a restraint
system in a child safety seat; a roughly triangular or “T” shaped pad that is
attached to the shoulder harness straps, fits over the child's abdomen and hips and
buckles between the legs) compared to forward-facing CRS with a system
restraining the child’s pelvis, and that adjustment and correct fitting of shoulder
straps were essential. It was stated that the shoulders of a young child are very
deformable and yielding, thus increasing the risk of a child slipping through too
loosely adjusted shoulder straps.
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VTI rapport 489A
A study by Kelleher-Walsh, Walsh, States and Duffey (1993) deals with
forward-facing CRS and the corresponding injuries. In total, 198 injured children
under five years of age in forward-facing CRS were studied. About 55 % of the
accidents were frontal collisions and 34 % were lateral accidents, while 10 %
were impacts from rear and 1 % was rollover accidents. Of the CRS used, 54 %
were harness types and 19 % were shield type CRS. When injuries were studied,
the author found that 57 % of the injuries were facial and an additional 19 % were
head injuries. Upper and lower extremities injuries each occurred in 7 % of the
cases and all other injury types represented less than 3 %. Among the severe
injuries the most frequent injuries were those to head and face in forward-facing
CRS.
The Seat Belt Syndrome (SBS) in children (Lane, 1994) was found to be a
problem with 2-point lap belts in forward-facing positions of children sitting in
rear seats. Abdominal gastro-intestinal injuries and kidney injuries might be the
consequence if two-point belts are used instead of three-point belts. The use of
three point belts and CRS was thus recommended. The risk factor is about
doubled for a child in a two point forward-facing belt compared with a three point
forward-facing belt system. Adults in outboard rear seats were at greater risk of
SBS by a factor 2.7 than passengers on the left front seat, i.e. the passenger seat in
a right hand drive car.
Spinal cord injuries in accidents have been studied by Stalnaker (1993). He
stated that children’s spine develops until about five years of age and recommends
rearward-facing systems as long as possible. Of seven investigated automobile
accidents with related child spinal cord injury, all but one injury could have been
prevented in appropriate protection systems, i.e. rearward-facing CRS. The
studied children were 1.5 to 55 months old.
In a reconstruction of a real world forward-facing CRS accident (Weber, 1993)
a dummy simulating a 6 month old child was subjected to an impact. Neck forces
exceeded 1,200 Newton (N). The technical conclusion of the report was that a
rearward-facing CRS would have been preferable.
The influence of harness type was studied in Pennsylvania and New Jersey
1997–1998 (Arbogast, Morris, Durbin & Winston, 2002). Convertible CRS (trayshields, T-shields and 5-point harness types) were found to have high (87–93 %)
misuse rates.
Cervical spine fractures sustained in forward-facing CRS were studied by
Fuchs, Barthel, Flannery & Christoffel (1989). They found that forward-facing
CRS for children younger than two years of age constituted a great risk. Five real
cases were studied. With a reference to Sweden the final recommendation of the
paper was that all children younger than two years and preferably younger than
four years should travel rearward-facing.
The risk of premature graduation of children to seat belts is treated in the dual
NHTSA internet documents (NHTSA, 2001c; NHTSA, 1998). It was found to be
common that parents put their children in the car without proper CRS. Children,
3–5 years of age, restrained only by a seat belt have a 3.5 times higher risk of
being injured than children in correct forward-facing CRS.
Injuries to children restrained in 2- and 3-point belts (Gotschall et al., 1998)
have been investigated in 98 cases. Contrary to other studies, in this specific study
very small or no differences in injury risk (AIS>2) were found between 2-point
and 3-point belts, but it appeared that 3-point belts were somewhat protective for
lumbar fractures.
VTI rapport 489A
33
In a study by Sweitzer, Rink, Corey and Goldsmith (2002), 499 children in
motor vehicle crashes have been studied. It was found that 33% were unrestrained
and 20 % were improperly restrained. Unrestrained children accounted for 70 %
of the fatalities. The restraint type was found to be of greater importance than the
seating position.
4.5
Use and misuse of restraints – observations and
questionnaires
4.5.1
Australia
A study funded by the Australian Transport Safety Bureau gives a background to
child car occupant safety in Australia (Browning, Ferguson, Swan & Robinson,
2000). A recent study in Western Australia, referred to by Browning et al.,
showed that approximately 11 % of metropolitan children did not wear CRS
whilst 15 % of rural children did not wear CRS. Furthermore, inadequate access
to child restraints was one reason for not using CRS. Browning et al. also reported
that a survey undertaken by Kidsafe WA indicated that more than 60 % of the
child car restraints were fitted incorrectly.
In the 1970s, Australia mandated child restraint use and adopted an attachment
system that incorporates an upper tether strap (FORS, 1996). Australian child
restraints attach to the car via the seat belt at the bottom and to dedicated
anchorage points on the vehicle by the upper tether strap. The need for the upper
strap precludes child restraints from being used in the front seat. In addition, some
State laws prohibit children of certain ages from riding in the front passenger seat.
Data for the years 1990/92/94 indicated that around 290 children under 16 years
of age who were killed or injured in an accident were unrestrained. This was some
25 % of children killed during the period. Compared with children who were
restrained, those unrestrained were more likely to be seriously injured (62 % of
unrestrained children compared with 53 % of children who were restrained). This
supports the case for making child restraint laws more stringent than is generally
reflected in present requirements.
To avoid misuse the Kidsafe organisation provides advice to the public on the
Internet (Kidsafe, 2003). This consists of common mistakes in using restraints and
a summary of the most dangerous misuses.
4.5.2
U.K.
In 1992, observed seat belt use for child rear seat occupants declined with age, so
that 88 % of children under the age of one were being restrained, compared with
60 % in the 10–13 age group (Transport Research Laboratory, 1992). New figures
from the Transport Research Laboratory (2002) show restraint use by car
occupants in April 2002. The use by car occupants of seat belts and other restraint
systems was observed at 32 sites chosen to represent all types of roads. Rear seat
belt use was examined in 28,000 cars on two extensive areas centred on
Crowthorne and Nottingham. The figures showed that 95 % of children from 0 to
13 years used a restraint in the front passenger seat. Ninety eight per cent of
children younger than one year and 97 % from one to four years were restrained
when travelling in the rear. The percentage was reduced to 86 % for 5–13 yearolds.
In Fife, Scotland, a study of restraint use was performed in 1995 and reported
by Campbell, Macdonald & Richardson (1997). The survey gathered data from
34
VTI rapport 489A
596 occupants in 180 cars: 327 adults and 269 children. Car occupant restraint
was assessed in 180 drivers, 151 front seat passengers, and 265 rear seat
passengers. Among all occupants, 61 % wore seat belts. Among children, 25 %
were restrained by a seat belt and booster cushion, 23 % in toddler seats, 9 % in
two way seats, and 7 % in rearward facing infant carriers. Overall, 97 % of
drivers, 95 % of front seat passengers, and 77 % of rear seat passengers were
restrained.
According to The Royal Society for the Prevention of Accidents, RoSPA
(2002) surveys have shown that a high proportion of child restraints are
incorrectly fitted, usually for one or more of the following reasons:
• Seat belt too loose
• Seat belt not routed through child seat correctly
• Buckle crunch (buckle resting against part of the child seat's frame, which
means that in a crash it might break or snap open)
• Handle on baby seat not positioned properly
• Child seat not compatible with car
• Child seat old and in bad condition
• Child too large or too small for the seat they are using.
The objective of the Fife study (Campbell, Macdonald & Richardson, 1997) was
to pilot data collection instruments and to make a preliminary estimate of the level
of incorrect use of car seat belts and child restraints. The method used was a cross
sectional survey of cars containing adults and children at a number of public sites
across Fife to assess use of car occupant restraints. Trained road safety officers
assessed whether seat restraints were appropriate for the age of the passengers and
whether restraints were used correctly. These assessments were based on
standards published by the Child Accident Prevention Trust. About 52 % of the
vehicles observed had at least one passenger restrained by a device that was used
incorrectly. Twenty eight per cent of the children were secured incorrectly. The
most common errors were loose seat belts and restraint devices not adequately
secured to the seat. Rates of incorrect use were highest in child seat restraints,
reaching 60 % with two way seats and 44 % with rearward facing infant seats.
The conclusions drawn by the authors were that the incorrect use of car occupant
restraints is an under-recognised problem, both by health professionals and the
general public. Moreover, incorrect use has been shown to reduce the
effectiveness of restraints, can itself result in injury, and is likely to be an
important factor in child passenger injuries. The correct use of car seat restraints
merits, according to Campbell, Macdonald & Richardson, greater attention in
strategies aiming to reduce road traffic casualties. Among areas of intervention
that could be considered are mentioned raising public awareness of this problem,
improving information and instruction given to those who purchase child
restraints, and encouraging increased collaboration between manufacturers of cars
and child restraints, in considering safety issues.
4.5.3
USA
In a national study in the USA, the change in use of restraints between 1993 and
1997 was investigated through telephone interviews (Bolen & Bland, 1999). The
number of respondents was 34,000–40,000 with approximately 660–770 per state.
The response rate was 71 % in 1993 and 62 % in 1997. The respondents were
VTI rapport 489A
35
18 years or older. The group investigated was the oldest child (younger than
15 years) of the respondent. The restraint use among children 0–4 years increased
from 91.2 to 93.7 %. Among children aged 5–10 years the rate increased from
82.6 to 90.1 % and for the age group 11–14 years from 69.0 to 79.1 %.
A national study in the USA recently showed that among 9,332 children aged
14 and younger, 14 % travelled unrestrained (Cody, Mickalide, Paul & Colella,
2002). The study was based on observations of 6,297 motor vehicles between
November 2001 and January 2002, captured at 174 sites in 48 states and the
District of Columbia. Older children were more likely to be unrestrained than
younger children. More than 20 % (558) of children aged 5 to 9 and nearly 24 %
(284) of children aged 10 to 14 were unrestrained. Furthermore, minority children
were more likely to travel unrestrained (23 %) than white children (10 %).
Moreover, nearly 33 % were using the wrong restraints for their size and age.
Older children were more likely to be in the wrong restraint than younger
children. More than 63 % of those who should have used booster seats (typically
ages 4 to 8) were inappropriately restrained, most often in safety belts. Drivers
who did not wear safety belts were less likely to restrain the children in their
vehicle. Nearly 40 % of children travelling with unbelted drivers were
unrestrained, compared with 5 % of children travelling with belted drivers.
Similar findings were reported by Decina & Knoebel (1997)
In a summary the National Highway Traffic Safety Administration, NHTSA
(2000) wrote that the effectiveness of child safety seats to reduce fatal injuries in
cars was 71 % for infants (younger than 1 year), and 54 % for toddlers (1–4 years
old). NHTSA has tried to estimate the number of lives saved by restraint systems.
During 1994-2000 an estimated total of 2,186 children younger than five were
saved, thanks to the use of restraints (CRS or adult seatbelts). Furthermore, in
2000, an estimated 316 lives of children under five years of age were saved,
282 were associated with the use of CRS and 33 with the use of adult seatbelts.
During the same year, a total of 529 children in the age below five years were
fatally injured as passengers in vehicle crashes in the United States. Of those,
251 children had not used any restraint, 219 used a child seat and 59 used an adult
seatbelt. At 100 percent child safety seat use among those children, an additional
143 lives could have been saved in 2000, according to the estimations.
Cody, Mickalide Paul & Colella (2002) state that efforts to increase child
occupant safety must be expanded and sustained over the next decade, including
the following measures:
• Closing gaps in existing child occupant protection laws.
• Upgrading safety belt laws to include primary enforcement provisions.
• Better education for caregivers about the increased risk of death or serious
injury for unrestrained children.
• Better information to caregivers about the importance of using the
appropriate restraints, with a focus on belt-positioning booster seats.
• Continued targeted outreach to at-risk populations, using culturally
appropriate messages and materials.
• Supporting more child safety seat distribution programs in communities in
need.
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VTI rapport 489A
To promote correct use of child restraint systems Biagioli (2002) gives a check
list, entitled “Common Misuses of Child Safety Seats”. The list contains the
following advises:
• No rearward-facing seats in front of an airbag.
• Children should face the rear until they weigh 20 lb and are at least one year of
age.
• The child's height and weight should be appropriate for the seat.
• Infant seats only in a rearward-facing position.
• Convertible safety seats are designed to face rearward or forward, but each
direction has weight limits. The child seat manual or the seat's label lists its
rearward-facing weight limit.
• A child seat should not be used in a side-facing seat
• Check that correct seat-belt path is being used.
• No more than 1 inch of side-to-side motion when the car seat is pulled
forcefully at the seat-belt path.
• Tether straps only in newer cars that have tether anchor sites
• To maintain the infant's airway, the back of a rearward-facing child seat should
be at a 45-degree angle from the ground.
• The carrier handle or sun shield of infant seats should be in the down position
while travelling.
• Harness straps should be snug enough that you cannot pinch the harness strap
(lengthwise, not crosswise).
• Harness straps should be flat and free of knots. Straps should not be ironed or
placed in a dryer.
• The harness clip should be at the armpit level.
• In a child seat that is facing rearward, the harness straps should be at or below
the level of the shoulder.
• In a child seat that faces forward, the harness straps should be in a reinforced
harness slot position. If more than one reinforced position, the harness straps
should be at or above the level of the shoulder when the child is forward
facing.
• Bulky clothes should not be worn under the harness straps.
• Missing or broken parts should be obtained only through the manufacturer.
• Check the seat for recalls.
• Child seats that have been in a crash should always be discarded and replaced
• A seat that is more than 10 years old should not be used, and it is best practice
not to use a seat that is more than six years old.
The 1998 Motor Vehicle Occupant Safety Survey (MVOSS), a national
telephone survey was conducted during the end of 1998 and the beginning of
1999. Block (2000) presents the survey findings pertaining to child restraints and
child occupant protection among children under the age of 6 and seating position
of children aged 12 and younger. About half of the children age 12 and younger
were said to be less likely at that time to ride in the front seat while 19 % were
more likely to ride in the front compared to one year earlier. The most frequently
given reasons why children were more likely to ride in the front seat were that the
child preferred the front and that there was no other place for the child. The most
frequently given reasons why children were less likely to ride in the front were
VTI rapport 489A
37
that it was safer in the back and the danger from air bags. The selected subgroup
of “parents/caregivers” were asked detailed questions about child restraint use,
misuse and non-use among children under the age of 6. The “parents/caregivers”
either reported that the child used a car seat “all the time” (71 %) or never used a
car seat (22 %). Nearly all infants (98–99 %) were reported to use car seats “all of
the time” if they weighed below 20 pounds (approximately 10 kg) or were
younger than 2 years of age. Discontinuation of car seat use by most children
occurred when the child was 3 or 4 years old and exceeded 40 pounds
(approximately 20 kg). The most frequent reasons mentioned for non-use of car
seats among part time users were that the child did not like the seat (31 %), the
seat was unavailable (30 %), or the child was only going to be in the car a short
time (29 %). Among children who never used car seats, the reasons given were
that the child was too big (84 %) and that the child was using a seat belt (94 %).
The vast majority of children who never used car seats were reported to wear seat
belts all (92 %) or most of the time (5 %) when riding in motor vehicles. Most
parents/caregivers (76 %) said they were aware of booster seats, but 21 % had not
heard of them. Among those who had heard of booster seats, 30 % had concerns
about their safety and another 7 % were unsure, according to Block (2000). Of
several information sources read by the interviewers, the parents and other
caregivers who drove a child that used a car seat most often said that they had
heard about the need to use car seats from TV or radio (65 %) or from books or
articles on child care (61 %).
A study by Glassbrenner (2003) found that during 2002 almost all infants
(99 %) under age one were restrained, this was compared with 95 % in 2000. Yet,
although all infants should be in a rear-facing restraint only 32 % were. Among
toddlers 8 % ought to be rear-facing, according to the author, while 4 % actually
were. Overall, 94 % of toddlers were restrained (compared with 91 % the year
2000), while only 83 % of children 4–7 years of age were restrained in 2002. The
restraint use estimates were based on the National Occupant Protection Use
Survey (NOPUS), conducted periodically by NHTSA. The survey also reported
that many young children still ride in the front seat; 15 % of infants, 10 % of
toddlers aged 1–3 and 29 % of children aged 4–7. The latest survey was
conducted in 2002, and its results were compared with the NOPUS made during
2000. Other findings were that the relation between restraint use of drivers and
their child passengers was strong. In 2002, more than 90 % of belted drivers also
restrained the children in their vehicles while only 72 % of unbelted drivers
restrained their child passengers.
An observational study of 1,258 children in Michigan, USA, showed that
almost 75 % of the children younger than 4 years used a child restraint when
travelling in cars, vans, sport utility vehicles (SUVs) and trucks (Eby &
Kostyniuk, 1999). The seat use was highest for children travelling in vehicles
driven by belted drivers and females. Inspections were carried out at a subset of
sites. In this pilot, seat misuse of some degree was found in 88 % of the
inspections. The most common type of misuse was associated with snugness of
fit, use of safety belt locking clip and the harness positioning clip. Drivers who
had a high occurrence of misuse had lower educational level, removed the seat
frequently from the vehicle, were not the parent of the child or had younger or
smaller children.
A similar study was performed and reported by Eby, Kostyniuk & Vivoda
(2001). The purpose of the study was to conduct a direct observation survey of
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restraint use designed specifically for older child passengers (4–15 years of age).
Furthermore, the factors that were related to belt use by older child passengers in
Michigan were to be determined in order to enable the development of effective
programs to promote use of restraint devices in this age group. The study found
that older child restraint use was about 58 %, state wide. Restraint use was highest
in regions where overall belt use was higher, when the driver was using a safety
belt, in sport utility vehicles (SUVs) and vans/minivans, and in the front-right
seating position. No difference in restraint use was found for the day of week, the
sex of the child, or the type of site where data were collected.
A study in the state of Georgia among 1,858 child car occupants younger than
13 years showed that 42 % of the children were properly restrained (Staunton,
Dellinger, Davidson & Powell, 2002). Among children 4–8 years, only 21 % were
using a suitable child restraint, while 75 % used only the seat belt and 4 % were
totally unrestrained. The change in restraint use among adults due to legislation
and the effect it had on child restraint use was also studied. The restraint use
among children aged 0–4 increased from 91.2 % to 93.7 %, among children aged
5–10 from 82.6 % to 90.1 % and among children aged 11–14 from 69.0 % to
79.1 %.
A study was conducted to determine the risk of significant injury associated
with premature graduation of young children (2–5 years) from child restraint
systems to seat belts (Winston, Durbin, Kallan & Moll, 2000). A representative
sample was selected, of children aged 0 to 15 years in crashes reported to
insurance companies in a sample of states. Driver reports of crash circumstances
and parent reports of child occupant injury were collected via telephone
interviews. Among children aged 2 to 5 years, 98 % were restrained, but nearly
40 % of these children were only restrained in seat belts. Compared with children
in CRS, children in seat belts were more likely to suffer a significant injury,
particularly head injuries, when compared with children in CRS. The conclusion
drawn was that premature graduation of young children from CRS to seat belts
puts the children at greatly increased risk of injury in crashes. A major benefit of
CRS was found to be a reduction in head injuries, potentially attributable to a
reduction in the amount of head excursion in a crash.
Misuse of booster seats among a sample of children attending 76 child safety
seat clinics in Pennsylvania and southern New Jersey has been studied by Morris,
Arbogast, Durbin & Winston (2000). Four different characteristics of booster seat
use were assessed (type, appropriateness for the child’s age and weight, the fit of
the child in the booster seat, the fit of the booster seat in the vehicle). Sixty eight
per cent of shield boosters and 20 % of belt positioning boosters were misused.
Thirty two per cent of the children using a shield booster weighed more than 40 lb
(18.1 kg); 68 % of children in shield boosters and 63 % in belt positioning
boosters weighed less than 40 lb. The majority of children in this study were less
than 40 lb. In this weight range, a convertible child restraint system provides
better protection than a booster seat. Booster seat use should only be initiated once
the child has completely outgrown their convertible child restraint system.
Altogether, 227 booster seats were observed. Booster seat practices were assessed
at 76 clinics by a child passenger safety team that evaluated the booster seat and
identified modes of misuse. In a further review of the data it was concluded that
the overall misuse rate of booster seats was misreported (Morris, 2001). Referring
the author the correct overall misuse rate of booster seats was 32 %.
VTI rapport 489A
39
The primary objective of another study performed by the same authors
(Arbogast, Morris, Durbin & Winston, 2002) was to quantify the relationship
between harness types and the prevalence of specific modes of misuse. Data were
collected at 21 child safety seat clinics in 1997 and 1998 in south-eastern
Pennsylvania and southern New Jersey. Convertible CRS are available in three
basic harness designs: five-point, T-shield, and tray-shield. Previous research has,
according to the authors, quantified the prevalence of misuse of child safety seats
and has identified specific misuse modes. Of the 438 convertible CRS evaluated,
roughly 90 % demonstrated at least one form of misuse. This rate of misuse did
not vary by harness type. Having marked/twisted harness straps was more
common among five-point harnesses. T-shields were more commonly recalled
due to defects with the shield buckle and harness retractor mechanism.
To determine if hands-on instruction in child safety seat (i.e. CRS) installation
decreases the number of errors in installation, cross-sectional studies were set up
at primary care offices, emergency departments and CRS checkpoints (Lane, Liu
& Newlin, 2000). Participants were parents of children younger than 2 years old,
receiving medical care or attending a CRS check. The results showed that only 6.4
% of parents had a correctly installed CRS. Hands-on instruction was associated
with fewer errors in seat installation. Increased parent age, completion of college,
and having private insurance were also associated with fewer errors in CRS
placement. The majority of parents learned to install seats from reading the
manual, from friends and relatives, and from figuring it out on their own. The
conclusions drawn by Lane et al. were that errors in CRS installation were a
significant problem. Hands-on instruction decreases the numbers of errors in CRS
installation. However, few parents received hands-on instruction from experts in
CRS installation. Hands-on education by trained professionals could result in
increased correct CRS use.
In a study by Weinstein, et al. (1997) the effects of not using an ageappropriate restraint system was examined and the effect of not using a restraint
system properly on injury severity. The authors found that improperly restrained
children in an age-appropriate restraint system sustained a greater proportion of
moderate or worse injuries (AIS 2–6) than properly restrained children who were
in the wrong restraint for their size. This was true particularly for infants and
small children who were likely to be in a child restraint system. The study
underscores the importance of proper use of restraint systems and makes
recommendations for improvements in restraint system designs for children as
follows:
1. CRS should be redesigned to simplify the placement of a child in the
restraint system
2. instructions should be simplified
3. integrated restraints should be offered
4. standards should provide for the secure and uniform installation of CRS
5. standards should be established for booster seats that can restrain children
up to 80 pounds
6. lap/shoulder belts should be provided at all center rear seating positions
7. adjustable upper anchorage points should be provided at all outboard
seating positions
The premature graduation of children from child restraints to vehicle safety belts
has been studied (NHTSA, 2001). The parents who used booster seats for their
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VTI rapport 489A
children knew more about child passenger safety issues and were more proactive
in seeking child safety information. Focus groups conducted in New Jersey and
Pennsylvania found that these parents perceived a higher risk of injury from a
motor vehicle crash for their children. In contrast, parents who only used seat
belts for their young children expressed confidence that they were protecting the
child from injury in the event of a crash effectively, using this type of restraint. In
the study, two groups of children are found to be prematurely graduated from
child restraints to seat belts: children under 40 pounds who should still be in child
safety seats; and children over 40 pounds who have outgrown their child safety
seats and moved to seat belts, but should be restrained in booster seats. Parents
frequently did not recognize the importance of keeping their child in a booster
seat until the seat belt fitted the child properly. Child resistance was a significant
barrier to extended use of booster seats. The parents of children still using booster
seats encountered the same types of resistance, but did not let the children make
the decision. Other barriers were the need to accommodate other children, motor
vehicle design, and situations where the seat was not available. Some parents
altered the method of restraint depending on the length of the trip, the weather, or
their own mood. Parents reported difficulties in installing the booster seats, and
also concerns about restraints that they thought offered insufficient protection. A
number of misperceptions about when a child is ready to graduate into a seat belt
were found. Parents want to do the right thing, but not all have accurate
information about which restraint to use and how. Laws provide poor guidance.
The parents suggested a number of strategies to encourage booster seat, for
example: to educate parents on successful parenting strategies including
consistency, setting boundaries, and communication; to provide free or low cost
booster seats use.
In a study by Ramsey, Simpson & Rivara (2000), booster seat use and reasons
for non-use were reported. The children were observed at day care centers and
drivers of unrestrained children were interviewed. One of the findings was that the
most common reason for lack of booster seat use was that parents thought the
child was large enough to use the regular lap-shoulder belt system, or problems
with attempting to use the seat in the vehicle. Overall, 28 % of children in the
target age group used booster seats; only 10 % of children 6 to 8 years old were
restrained with booster seats. Booster seat use decreased when there were 3 or
more passengers in the vehicle. More than one half of parents who were not using
booster seats at the time of the survey reported owning seats. The conclusions
drawn were that the results indicate that parental misconceptions about size and
safety of regular restraint equipment are the most common reason that children are
not appropriately restrained in vehicles.
The objective of a study reported by Simpson et al. (2002) was to identify
barriers to booster seat use and strategies to increase their use. The study
demonstrated that, in particular, differences in risk perception,
awareness/knowledge, and parenting style were noted when comparing parents of
children in booster seats with those whose children were in seat belts only. Media
campaigns, improved laws, parenting education, and extending the use of child
restraints to older ages were among the strategies suggested by parents to increase
booster seat use. The study provides insights from parents about their perceptions
regarding booster seats, how parents make safety decisions for their children and
the important role of children in this decision-making process. The method used
was a qualitative study consisting of focus groups with follow-up in-depth
VTI rapport 489A
41
discussions among parents and/or children. The total number of participants was
111.
Biagioli (2002) advises physicians to provide parents with information about
child occupant safety, such as advice, pamphlets, web-site addresses, information
about check-up clinics and community’s safety seat experts and to use a
multidisciplinary approach in educating parents about the correct use of child
restraints.
The objectives of a study conducted by Wegner & Girasek (2003) were to
measure the required reading level of a sample of child safety seat (CRS)
installation instructions and to compare readability levels among CRS if different
prices. Another objective was to determine whether the lower cost seats (to which
low-income parents have greater access) are addressed to readers with a lower
level of education. In the study a CD-ROM containing CRS installation
instructions was used, obtained from NHTSA. Paper copies of the instruction sets
were generated, and their readability levels were determined. No significant
associations were found to exist between readability and seat prices. The
conclusions drawn were that CRS instruction manuals were written at a reading
level that exceeds the reading skills of most American consumers. Consequently,
instruction sets should be written at a lower reading level to encourage the proper
installation of CRS.
In a US national survey (Boyle, 1995) it was found that 29 % of the parents
transporting children in rearward facing CRS believed that the combination of
rearward facing CRS and passenger side airbag was safe. An additional 15 %
claimed they did not know whether it was safe or not, or said that they did not
know how airbags work. Of those who mistakenly believed that there was not any
danger from the airbag, approximately 3 % had a passenger-side airbag in their
primary vehicle. In the survey, two additional problems were identified related to
young children not being fastened into their car seat; about one out of five (22 %)
parents/caregivers reported that it happened that their child entered the car seat
while riding in the vehicle. This was most common among children who used
booster seats. Among part-time car seat users, 22 % of children usually rode in
another passenger’s lap when they were not in their car seat.
4.5.4
Sweden
In Sweden, the changes in seat belt usage in cars have been studied through
annual observations at a sample of roundabouts since 1983 (Cedersund, 2002).
From a level of less than 20 % in 1983 the proportion of restrained children in the
rear seat increased rapidly to over 60 % in 1986. Since the end of the 1990’s the
level of restraint usage among children has been almost 90 % in the rear seat. Seat
belt usage became mandatory in the rear seat in 1986 for adults and in 1988 for
children.
In a national survey, restraint use and misuse was investigated (Anund, Yahya
& Sörensen, 1998) through questionnaires. The questionnaire had, however, some
disadvantages and improvements were therefore introduced when a similar study
was performed in the west of Sweden (Anund, Sörensen & Yahya, 1999). Overall,
no large differences were found, when the results from the west of Sweden were
compared with the study among randomly selected children in the whole country.
In the study covering the west of Sweden (Anund, Sörensen & Yahya, 1999)
the questionnaire was answered by 2,358 parents with children in the age from
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two month to nine years. Questions were asked about the travel habits of the child
who had been selected randomly. Overall, the proportion of children who always
used a seat belt was estimated to 83 %, while another 12 % claimed to use the seat
belt during 99 out of 100 trips. The remaining 5 % used the seat belt less often.
In the same study (Anund, Sörensen & Yahya, 1999) it was found that almost
25 % of all the children travelled, in at least one out of twenty trips, in a car
without using a child restraint. Among children younger than three, the
corresponding proportion was 6 %. The recommendation at the time of the study,
i.e. 1998, was that all children younger than ten years of age ought to use child
restraints, while child restraint use was, and still is, mandatory for all children up
to and including the year when they become six years old. Children younger than
three years were recommended to travel facing backwards. Despite this, almost
25 % of children younger than three years did not follow this recommendation.
Moreover, during their first journey ever, approximately 10 % of all children in
the west of Sweden travelled unrestrained.
Restraint and child restraint use and misuse were studied in Östergötland,
Sweden. Observations of 274 child car occupants arriving at supermarkets, child
care centres and central city blocks showed a misuse percentage of almost 40 %,
including non-users. Ten percent of the children were not using any kind of
restraint at all. Among children younger than three, nearly 30 % travelled
forward-facing. The main misuse factor was misplacement of seatbelt (Anund,
1998).
In a questionnaire based survey in the west of Sweden (Anund, Sörensen &
Yahya,1999) 10 % of the children younger than three were reported using booster
seats or booster cushions and another two percent used no child restraints at all.
One quarter of the children younger than three travelled forward-facing. One of
the main reasons for changing to a forward-facing position was that there was not
enough space for the feet/legs of the child or that the child was unhappy with
travelling rearward-facing. Among children aged 3–9 twelve per cent did not use
any child restraint at all. There was a correlation between the age of the child and
the use of child restraint. Among children aged 1–2 approximately 7 % travelled
at least one out of 20 trips without child restraint. Among children aged 3–9 the
corresponding percentage was 30 %.
There was a significant correlation between the percentage of front-facing
children younger than 3 years and the educational level of the parents as well as
the household income. Among children of age 1–2, there were 43 % forwardfacing children with parents with lower education. However, only 16 % of the
children with parents with higher education were forward-facing. There was,
however, reason to believe that there was a strong correlation between level of
education and household income. Immigrant parents had not received or looked
for information about child occupant safety to the same extent as parents born in
Sweden. Furthermore, there was also a correlation between immigrant parents and
non-use of child restraints. Approximately ten per cent among children with one
or two parents born outside Sweden did occasionally travel unrestrained. The
corresponding percentage for children with parents born in Sweden was four per
cent. The percentage of children in the age group 0–2 travelling forward-facing
was also higher among those with parents from another country. In one part of the
questionnaire the knowledge about rules and recommendations was investigated.
Although less than 60 % of all the answers were correct overall, more than three
VTI rapport 489A
43
out of four parents were convinced that their child travelled according to
recommendations and regulations.
Krafft (2000) argues that car producers do not take child car safety seriously
enough. Frontal collisions are the most common type of collisions. From a crash
safety point of view rearward facing child restraints in the front seat are the safest
way of transporting four year old children in cars in case of a frontal collision,
says Kraft. Few cars are, however, produced without a passenger front/side
airbag, although this is the safest position for rearward facing child car seats in
case of a frontal collision.). One main reason for premature graduation from
rearward facing restraints is the lack of space in the rear seat. Due to this reason,
already at the age of two, children are being moved into a front facing restraint.
Instead, the front seat should be available for rearward facing restraints and
equipped with specific attachments for the child restraint.
In a study by Wenäll (2003), the Swedish laws and recommendations for child
restraints in passenger cars are discussed. Furthermore, advises to parents and
other user groups are given, based mainly on the experiences from a great number
of different approval tests, including many crash tests. The Wenäll study supports
the statements above quoted from Krafft (2000)
Another questionnaire based study in part of Sweden (Forward, Kós-Dienes &
Obrenovic, 2000) showed the attitude and behaviour among approximately
300 Swedes and 300 immigrants, 38 % arriving in Sweden in 1985–1990 and
62 % arriving in 1991–1997. The results showed that immigrants were less likely
to use child seats for their children. The general opinion was that children are safe
enough travelling in the rear seat or sitting on the lap of an adult holding them.
Many immigrants were ignorant of the risk of unrestrained children hitting the
windscreen in case of an accident. A reason why seatbelts were not worn was that
families with many children said they had no possibility to use a seat belt in the
rear seat. The immigrants considered the use of child seats in the rear seat less
attractive, since fewer passengers then could be seated there. The study
recommends traffic safety information campaigns targeted at immigrant groups.
Tingvall (1987) investigated child safety in cars from different aspects,
including restraint use effectiveness, restraint use limitations and drawbacks, data
quality and improper use of child restraints. Questionnaires were used for studies
of restraint use effectiveness. Data on injuries reported by the police were used for
studies of limitations and drawbacks of restraint use. Observational studies were
conducted to detect improper use of child restraints and these were followed-up
by dynamic barrier tests to assess possible consequences in frontal collisions.
Misuse of child restraints was found to exist which may decrease restraint use
effectiveness or induce injuries. On the basis of these studies it was recommended
that child restraints should be incorporated into cars as an in-built system with the
same basic design as restraints that are available as extra equipment. However,
certain considerations should be paid to those injuries occurring among restrained
children that entail a risk of medical disability.
Long-term effects of legislation and local promotion of child restraint use in
motor vehicles in Sweden have been analysed by Ekman, Welander, Svanström &
Schelp (2001). The study included children from two age groups, 0–6 years and
7–14 years. Data from observational studies of car seat belt usage was used.
Outcome evaluation was based on hospital-discharge data 1978–1996 and
mortality statistics 1970–1996. The level of restraint use for children in the front
seat was found to be 97 % in both 1988 and 1995. Mortality data showed a
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decrease of 76 % over the 27 years studied. Hospital discharge showed a
significant change over time in two intervention areas, but not in the rest of
Sweden. The local authorities that started early with preventive programmes, such
as safety seat loan schemes and those which have organised safety-promotion
programmes showed a better improvement than the rest of Sweden. The
conclusion drawn was that there is a need for appropriate information for local
action on childhood injury prevention to accompany national legislation.
A standard empirical test procedure, ISO 8317, was applied to the study of
child restraint misuse (Bell, 1991). A pilot group of 20 parent-couples was
presented with a booster seat, including the permanent instruction that was fitted
to the product, and were observed while installing the seat. One objective of the
study was to determine whether such a panel procedure could be applied by lay
investigators. Another objective was to determine whether potential sources of
misuse could be identified. Ten of the couples made no mistakes and eight
couples made errors that were judged to be less serious. Although this booster seat
was held by experts as easy to use, two couples made serious errors. One couple
placed the diagonal part of the adult seatbelt under the arm of the child. The other
couple made an error when positioning the booster seat into the car that might
lead to submarining in case of a collision. The study concluded that lay
investigators can evaluate a product for a manufacturer, using such misuse testing.
The technique can illuminate specific product drawbacks. Potentially, such testing
might be part of the product approval or certification process. At the same time,
this policy calls for cautious application, as improving products for misuse
prevention does not necessarily lead to better products for injury prevention.
Systems based on the principle that elements for child seat fastening are
already mounted in the car seats or chassis when delivered have been investigated
with respect to correct mounting among parents of small children (Berg &
Gregersen, 1992; Berg 1998). The results show that the systems minimise
incorrect mounting and that parents are willing to pay a fairly large amount of
money for installation in their car. The ISOFIX system is ranked highest when it
comes to simplicity of use and was also ranked highest regarding how stable or
safe the seats seemed when fastened.
Incorrect use of car safety seats for children leading to an unexpected risk of
strangulation has been pointed out by Björnstig, Eriksson & Holm (1997). Parents
were advised to use child seats with crotch strap only, especially if used forwardfacing. The problem does not seem to occur if the child restraint is fitted
rearward-facing, because the risk of sliding out of the seat is prohibited by the car
seat back rest. When a child restraint without a crotch strap is used, however,
there is a potential risk of strangulation. The authors give an example of a case
where a one-year-old boy fell asleep while sitting in his child seat and was found
unconscious by his parents. The boy had slid down and was hanging by his throat.
His father gave first aid, which most likely saved the boy's life. The boy, however,
did not regain consciousness at the hospital until five hours later. Fortunately,
after a month he did not seem to suffer from any long lasting injuries.
4.6
Socioeconomic aspects
In some studies a relation has been found between level of restraint use and
different socio-economic factors (Gustafsson, Anund, Sörensen & Vogel, 2003).
Examples of factors found to be positively related with restraint use are: income,
VTI rapport 489A
45
and level of education. Situations or groups in which restraint use has been found
to be low are:
• children from minority groups (such as immigrants),
• where restraints are reported to be frequently removed from the car,
• children in cars not driven by females, parents or belted drivers,
• in cars with more than two passengers,
• in minibuses, and caravans
• in the middle rear seat.
Situations or groups where level of usage was found to be high were:
• in rural areas,
• in SUVs and vans (Michigan),
• in the front-right seating position,
• in states with primary child restraint laws.
Other factors for restraint usage mentioned were differences in risk perception,
awareness/knowledge, parenting style, purpose of the journey, and doubting the
effectiveness of the restraint system used.
One study indicates that parental misconceptions about size and safety of
regular restraint equipment are the most common reason for children not being
appropriately restrained. This particular study mentions that the most common
reason for lack of booster seat use was that parents thought the child was large
enough to use the regular lap-shoulder belt only, or had problems with attempting
to use the seat in the vehicle.
The National Transportation Safety Board found that improperly restrained
children, in particular infants and small children, in age-appropriate restraint
systems sustained a greater proportion of severe or moderate injuries than
properly restrained children who were in the wrong restraints for their size.
4.7
Measures for improvement – Campaigns
4.7.1
Australia
Roads and Traffic Authority (RTA) (Roads and Traffic Authority New South
Wales, 1992) in New South Wales in Australia carried through an occupant
restraint campaign during 1991 and 1992 focused on the use of occupant restraints
by children aged 5 to 13 years. The RTA commissioned RAMIS Corporation to
conduct a telephone survey of the awareness of the campaign activities amongst
the general and target (parents with children aged 5-13 years) population. The
survey was conducted to evaluate:
• awareness of RTA occupant restraint advertising, together with advertising
content, messages and perceived target audiences
• awareness of public relations activities
• awareness of and attitudes towards occupant restraint use enforcement
activities, and perceived probability of being caught by the police and legal
responsibility for enforcement
• awareness and usage of safety restraint fitting stations
• perceived impact of campaign activities.
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Claimed awareness of past three month television advertising about wearing seat
belt or occupant restraint was 83 %. Unaided awareness of radio advertising about
wearing seat belts or occupant restraints measured 23 %. Overall, 35 % of the
respondents indicated awareness of safety restraint fitting station, but only four
per cent of parents with children in the 5–13 year age group indicated they had
actually made use of a fitting station. One in four respondents indicated awareness
of occupant restraint campaign activities other than television advertisements and
radio commercials, for example billboards/road signs, newspaper articles or police
blitz. Knowledge of the legal responsibility for ensuring that children under
14 years of age are restrained was high, with 73 % nominating the driver. Seven
in ten of parents with children aged 5–13 years, whose oldest child had been
exposed to the advertisements, reported they already ensured their child was
restrained. 15 % of these parents felt the advertising had encouraged seat belt use
and 15 % affirmed that their own behaviour had altered with respect to how they
treat their child’s seat belt use as a result of the advertising. They were more
aware of the importance of children being restrained.
In New South Wales in Australia a communication strategy was developed to
specifically address the needs of occupants from a non-English speaking
background (NESB) (Preece, 1994). The objective was to increase knowledge,
awareness, and commitment of NESB parents/carers toward restraint use by rear
seat child passengers. The communication strategy should:
1. Create a heightened level of awareness in NESB communities about the
safety of children in vehicles, to the point where occupant restraint use by
children becomes an issue of concern for all NESB parents.
2. Make parents from non-English speaking backgrounds aware that their
children are not safe if they travel unrestrained in the rear seat.
3. Target parents of children between 1 and 13 years, concentrating on the
5–8 years age group.
4. Alert NESB parents to the fact that the driver is responsible for ensuring
that child passengers are restrained, and failing to do so means a fine and
points.
A pilot campaign was accomplished in November and December 1993 as an
integrated marketing initiative. Three language groups were targeted – Arabic,
Italian and Vietnamese. As an introduction to the campaign, Ethnic
Communications (ETCOM) organised a media briefing, which was well attended
by both radio and press from the target communities. A media kit was developed
and distributed by ETCOM to each of the media outlets in the three language
groups. ETCOM provided an abundance of professional and detailed resource
information, which was effectively disseminated throughout the communities via
education, health, social and welfare groups and organisations. In terms of actual
awareness of the campaign, 64 % of parents reported seeing or hearing advertising
or information in the past three months about restraint used by children. 44 % of
parents, who were shown some of the printed materials which had been part of the
campaign, stated that they had seen the materials. Observational surveys of rear
seat restraint use by children from the three target communities were conducted
prior to and following the campaign. The surveys found that none of the three
communities recorded a statistically significant increase in child restraint usage.
A major restraint usage promotional campaign with the theme “There’s No
Excuse, So Belt Up” was conducted in Victoria in Australia between 7 June and
VTI rapport 489A
47
15 July 1989 and reported by Wise and Healy (1990). The key messages were
directed to both front and rear seat occupants including parents who allowed their
children to travel unrestrained. The campaign included two television
commercials contrasting the excuse vehicle occupants often use with the tragic
consequences of not wearing a restraint, six radio commercials covering the
similar themes but also emphasising increased Police enforcement, and a press
advertisement appearing in major metropolitan and regional papers depicting a
Traffic Infringement Notice issued by the Police with the fine for not wearing a
seatbelt highlighted. A “before” and “after” survey showed significant increase in
restraint wearing rates between 1988 and 1989 for the total of occupants and for
rear seat passengers overall. There were significant increases in the restraint
wearing rates of front passengers aged 14 to 25 years and of rear passengers aged
8 to 17 years. Increases were greatest in rural towns and for rear seat occupants.
Victoria Police figures showed an increase in enforcement accompanied the
campaign.
Robyn Seymour from Royal Automobile Club of Victoria (RACV) reported at
a conference in Australia from a campaign to promote awareness of child restraint
issues (Seymour, 2000). The campaign was promoted to encourage
parents/guardians to:
• have their child restraints professionally fitted
• ensure that the children are in the appropriate restraint for their size and
weight
• ensure that the restraint is always done up.
Three radio advertisements were developed, focusing on this message, and ran
throughout Victoria for six weeks, on commercial radio stations whose main
audience were people with children under the age of six. A poster with the title
“Will you child survive a crash?” were distributed to all Victorian maternity
hospitals, community centres, maternal and child health centres and to child care
centres. Two articles relating to the child restraint campaign appeared in the
RACV RoyalAuto Magazine. A brochure, the “Buyers Guide to Child Restraints”,
that listed all the restraints that received a preferred buy rating, was distributed to
relevant outlets, agencies and organisations. The author reported that the
campaign was a success even though it was difficult to evaluate its effectiveness.
However, a survey of the campaign showed that the awareness of the advertising
was high and reached its target audience. The key messages that respondents
recalled from the advertising accurately reflected the key messages of the
campaign.
Browning et al., (2000) describes a regional intervention targeted at increasing
appropriate child car restraint usage in 4–7 year old rural school children. Out of
598 families, classroom intervention was targeted at 289 children. The
observational study, however, involved all children at the schools. In total 900
observations were made. During the one month observation the children were
rewarded by their teachers if they had been buckled up when being driven to
school. Stickers were also handled out to children being observed wearing a
restraint on arriving at school. Brochures and information sheets on child car
safety were handed out to parents. Overall, observations showed that child car
restraint usage was significantly increased from 79 to 90 %. Use of ageappropriate child car restraints increased from 45–51 to 69 %. No significant
48
VTI rapport 489A
increase in seat belt usage was observed among the children. The main seating
positions for children were either front side or rear/side of the vehicle. Among the
children not wearing a child restraint, 38 % were seated in the front passenger
seat. A questionnaire showed that the majority of the 139 parents that had
answered believed that not everyone can tell if a child restraint is incorrectly worn
or installed and 40 % considered the restraints to be too expensive. Nevertheless,
no more than 3 % of the parents took the offered opportunity to have their child
restraints checked. Overall, 17 % of the children were reported to climb out of
child car restraints or do not like to be strapped in such a device.
4.7.2
U.K.
In March 2000, the U.K. government set targets to reduce deaths and serious
injuries by 2010, a 40 % reduction overall and a 50 % reduction for children.
Therefore the Government introduced a campaign called “THINK!” (Think!:
driver requires all your attention, 2000), which is still going on. THINK! is a year
round road safety campaign aiming to create a greater public awareness of all road
safety issues through publicity on television, radio, press, posters and other media
The campaign is supported at local level by police and local authority road safety
officers as well as voluntary and private sector organisations. A child restraint
campaign, called “THINK! Child car seats”, is part of THINK! The aim of the
campaign was to advise parents and carers on how to fit child seats correctly. The
campaign wanted to direct parents/carers to road safety officers for further advice
on fitting and choosing car seats or for names of reputable manufacturers or
retailers. Radio and press advertising were used and the campaign worked with
many third parties to help promote the message. A 30 second radio advertisement
was produced and was aired on national and commercial radio stations in one
week in February 2001. An A5 leaflet and a handy peel-off card with advice and
useful tips were produced to support the advertising. Other examples of activities
in the campaign was an advertorial placed in the March 2001 edition of Mother &
Baby magazine and Britax installation experts checking over 1,000 child car seats
in 10 Safeway car parks across the UK. Quantitative research revealed that 54 %
of people and 59 % of parents of children aged 0–4 were aware of publicity
regarding child car seats during the week of advertising. The campaign continued
with press advertisements in a variety of parenting press and women's magazines,
distributions of a pocket guide providing a full checklist of tips on buying, fitting
and seating children in car seats, press notices and TV-fillers.
4.7.3
USA
The Task Force on Community Preventive Services has conducted systematic
reviews of interventions designed to increase use of child safety seats, increase
use of safety belts and reduce alcohol-impaired driving (Zaza, et al., 2001; U.S.
Department of Health and Human Services, 2001). The Task Force used the
Community Guide’s methods for conducting systematic reviews and linking
evidence to recommendations. The development team, a multidisciplinary team,
focused on the goals of NHTSA and the Healthy People 2010 objectives related to
motor-vehicle occupant injury.
The NHTSA goal concerning CRS is to reduce child (aged 0–4 years) occupant
fatalities by 25 % by the year 2005 (from 653 fatalities in 1996). Healthy People
2010 objective is to increase use of child restraint devices for passengers aged
VTI rapport 489A
49
0–4 years from 92 % (1998 preliminary data age-adjusted to the year 2000
standard population) to 100 %.
The consultation team generated a comprehensive list of strategies and created
a priority list of interventions for review. The interventions were either singlecomponent (i.e., using only one activity to achieve desired outcomes) or multicomponent. Studies were grouped on the basis of the similarity of the
interventions being evaluated. Interventions and outcome measures were
classified according to definitions developed as part of the review process. To be
included in the reviews of effectiveness, studies had to:
• be primary investigations of interventions selected for evaluation
• be published in English during 1966–June 2000
• be conducted in established market economies
• compare outcomes among groups of persons exposed to the interventions
with outcomes among groups of persons not exposed or less exposed to the
intervention.
For each intervention reviewed, the team developed an analytic framework
indicating possible causal links between the intervention under study and
predefined outcomes of interest. To make recommendations, the Task Force
required that studies showed increase in use of child safety seats or safety belts or
decrease in motor-vehicle crashes or crash-related injuries. Each study that met
the inclusion criteria was evaluated using a standardized abstraction form and
assessed for suitability of the study design and threats to validity. Results on each
outcome of interest were obtained from each study that met the minimum quality
criteria. The strength of the body of evidence of effectiveness was characterized
as strong, sufficient or insufficient on the basis of the number of available studies,
the suitability of study designs for evaluating effectiveness, the quality of
execution of the studies, the consistency of the results, and the effect size.
On the basis of the evidence of effectiveness, the Task Force either strongly
recommended or recommended four interventions to increase use of child safety
seats. These interventions were:
• Laws requiring use
• Community wide information and enhanced enforcement campaigns
• Distribution and education programs
• Incentive and education programs
The Task Force strongly recommended or recommended three interventions to
increase safety belt use. These interventions were:
• Laws requiring use
• Primary enforcement laws
• Enhanced enforcement programs.
The Task Force found insufficient evidence on which to make recommendation
regarding education-only programs to improve child safety use, because of
inconsistencies in the curricula, target populations, and effects of reported
interventions.
The Task Force recommendations can be used to support or expand child
safety seat distribution programs, bolster the use of incentives, and employ
enhanced enforcement campaigns, all in conjunction with community wide
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VTI rapport 489A
education efforts. For example, the recommendation for child safety seat
distribution and education programs could help a community decide to
concentrate the distribution of low-cost or no-cost child safety seats in lowincome neighbourhoods or to seek local sponsorship to defray the cost of seats
distributed to needy families.
The Buckle Up America (BUA) was a national initiative announced in January
1997 directing the Department of Transportation (DOT) to prepare a plan to
increase seat belt usage nationwide (Solomon, Leaf & Nissen, 2001; Buckle up
America., 2001; NHTSA, 2001b). In response, NHTSA developed a plan to
1. increase seat belt use to 85 % by the year 2000 and to 90 % by 2005 (from
68 % in 1996);
2. decrease fatalities to children under the age of five by 15 % by 2000 and by
25 % by 2005 (using 653 fatalities in 1996 as a baseline).
There are four components to BUA:
1. building partnerships, to bring all aspects of the community to bear;
2. enacting new legislation, to make it clear that elected officials are behind
BUA;
3. conducting strong enforcement, to make sure the public understands that nonuse can have immediate costs; and
4. expanding public information and education, to continue educating and
motivating the public to use seat belts and to provide specific how-to
knowledge to those using child safety seats.
Child restraint use has improved markedly for children under age five and
fatalities have decreased dramatically. In 1998 fatalities had decreased by 20.9 %
for children under age one, and by 8.6 % for children aged one through four. The
goal of reducing child occupant fatalities (0–4 years) by 15 % by the year 2000
was reached in 1999 – one year early. This decrease in the number of childhood
traffic deaths is, in part, due to the dramatic increases in child restraint use since
the Buckle Up America Campaign began. Restraint use among infants (1–12
months) was measured at 97.2 % in 1998, compared to 85.2 % in 1996 just before
the Buckle Up America Campaign began. In 1996, only about 60 % of toddlers
(1–4 years old) were restrained while riding in vehicles; in 1998, over 90 % of
toddlers were restrained. The increase in restraint use is not as dramatic among
children 5–15 years old, but it is nonetheless significant: an 11 percentage point
increase in only four years, from 57.7 % in 1994 up to 68.7 % in 1998.
Seat belt use among adults has also increased after the inception of Buckle Up
America. The District of Columbia and 38 States reported an increase in seat belt
use rates in 1999. However, in 1999, only five states and the District of Columbia
were at or above 80 % belt use; all are jurisdictions having standard seat belt laws.
During year 1999, 24 States proposed legislation that would upgrade their seat
belt laws and six States amended their child passenger safety laws. In May 1997,
the Air Bag & Seat Belt Safety Campaign, in cooperation with NHTSA, began a
national effort known as “Operation ABC Mobilization: America Buckles Up
Children”. The Mobilization was based on a highly effective law enforcement
model that combined periodic waves of stepped-up enforcement with aggressive
publicity highlighting the enforcement.
Overall public support for seat belt and child passenger safety laws has been
strong. A 1998 survey by NHTSA showed that 86 % of those surveyed favoured
VTI rapport 489A
51
laws that require drivers and front-seat passengers to wear seat belts. A 1999
survey conducted by the Air Bag & Seat Belt Safety Campaign found that 78 % of
those surveyed agreed with the statement, “People who fail to buckle up their
child passengers should be considered guilty of child endangerment”.
The Transportation Equity Act for the 21st Century (TEA-21) has created two
Federal incentive grant programs to encourage States to increase the use of seat
belts and child safety seats: “Section 405 incentive grants” and “Section 157
incentive grants”. These grant programs are designed to encourage States to
increase seat belt use rates and target specific occupant protection laws and
programs. Section 405 created a new incentive grant program to increase the use
of seat belts and child safety seats by encouraging States to adopt more effective
laws, stronger penalties, and highly visible enforcement and education programs.
Section 157 created a program to encourage States to increase their seat belt use
rates in recognition that increased belt use decreases crash injuries and the
financial burden these preventable injuries place on Federal programs. Funds were
allocated to eligible States based on savings in medical costs to the Federal
government due to improved seat belt use.
The Buckle Up America Campaign is said to be a success and that depends on
hard work and dedication of literally hundreds of partners in both government and
the private sector. There are federal initiatives in order to promote the use of seat
belts among U.S. Department of Transportation employees and their customers
and other federal agencies outside the DOT. Usage among Federal employees
continues to be significantly higher than among the general population. Initiatives
by the States are said to be absolutely essential in achieving the goals of the
Buckle Up America Campaign. It is up to the States to upgrade their child
passenger safety laws and to enact standard legislation. It is also up to the States
and local communities to enforce these laws. NHTSA developed partnerships
with literally hundreds of organisations to effectively and appropriately reach all
Americans through the Buckle Up America Campaign. These partnerships ensure
that the message goes to the farthest reaches of the nation and gives communities
a sense of "ownership" in helping to save lives and reduce injuries within their
own geographic area. Hundreds of private organisations have joined NHTSA in
spreading the message of the Buckle Up America Campaign. Small businesses,
large companies, physicians’ groups, and college fraternities and sororities are just
a few organisations that have been on the front lines to encourage everyone to
buckle up on every trip.
To effectively reach all Americans through the Buckle Up America Campaign,
NHTSA has developed strategies especially targeted towards African Americans,
Native Americans, Asian Americans, Hispanic Americans, and people living in
rural communities. NHTSA has also had a special challenge to reach children and
teens since traffic crashes are the leading cause of death from age one through
age 24. Another critical population important to reach with activities designed to
increase safety belt use is people in rural areas, particularly young men.
To ensure that the goals of the campaign are met by 2005, NHTSA will
continue to build and maintain partnerships, support law enforcement officials,
deliver effective public education, and devise new technologies to promote
occupant protection. NHTSA will also maintain its commitment to support States
in their efforts to enact strong legislation that helps to protect all Americans as
they travel in motor vehicles. NHTSA will also focus its efforts on high-risk
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VTI rapport 489A
groups, including children and teens, minorities, part-time seat belt users, and
those living in rural areas.
DaimlerChrysler partnered with Fisher-Price (a leading manufacture of child
safety seats) and the National Safety Council and established a program called
“Fit for a Kid” including permanent “fitting stations” to address non-use and
misuse of child safety seats (Solomon et al., 2001). Pilot projects began in four
cities by September 1999 and the goal was to have trained and certified child
safety seat inspectors in 1,500 dealerships by November 2000. Fisher-Price
contributes expertise and material support to the program and the National Safety
Council conducts the employee-training courses. The Fit for a Kid program will
create the capacity to inspect and assure proper installation of 800,000 seats
annually.
In March 1995, under an agreement with the U.S. Department of
Transportation, General Motors Corporation (GM) agreed to provide funds over a
five year period to support highway safety research and programs to prevent
motor vehicle deaths and injuries (NHTSA, 1999). One of the programs supported
was the National Child Safety Seat Distribution Program (National Child Safety
Seat Distribution Program Evaluation Assesses, 1999). GM provided non-profit
organizations with funding to provide convertible, infant, booster, and special
needs seats to families who could not otherwise obtain a seat in all 50 states, the
District of Columbia and Puerto Rico. An administrative evaluation on this
national distribution program was conducted. Over half of the facilities were
medically related, like hospitals or community health centres. Nearly all facilities
assessed recipient need before giving out a seat, and most trained all of their
recipients. Most of the seats were given to recipients for permanent ownership.
Training included demonstrations of safe use, hands on training, use of videos and
lectures, and installation of the seat into the recipient’s vehicle. Programs at
medical related facilities appeared to work best because they were more likely to
have trained staff and related programs in place already and were also more likely
to find qualified recipients in-house.
4.7.4
Sweden
Parents of new-born babies in Blekinge in the south of Sweden (Anund &
Sörensen, 2001) were offered to be members of a campaign called “Säkereken”
and receive up-to-date information on how to protect children in traffic. The most
common source of information was the Child Health Centre. The authors
evaluated the level of safety when the children who participated in the campaign
were travelling by car. The results were compared with results from an earlier
study of a random sample of families in Blekinge. The comparison indicated that
children who were members of “Säkereken” travelled more safely. Their parents
also seemed to know more about traffic safety. For example it was more common
for those parents to answer correctly to the questions about where to position the
safety belt. In spite of parents' knowledge, children still travelled with the safety
belt under the arm instead of on the shoulder or in restraints facing forwards
although the children were recommended to travel facing rearwards. Parents who
were members of the campaign were expected to have received more information
on how to protect children when travelling by car, but this proved not to be the
case. The information had not been received or absorbed by all the parents. The
authors found in the study that parents had gaps in their knowledge which they
VTI rapport 489A
53
were not aware of. According to the authors, the parents have to be aware of their
gaps in knowledge to be motivated to take in information.
4.8
Children with disabilities
4.8.1
Children with disabilities and transportation safety
equipment
Children do not form a homogeneous group. In Sweden, approximately 100,000
children are born annually, more than 1 %, probably 2–5 %, will eventually have
a disability during childhood (Falkmer & Paulsson, 2003). The group of children
with disabilities consists mainly of children with congenital diseases (Molin,
1987; Paulsson & Fasth, 1998).
Child safety seats are developed for children without disabilities. Children who
are born with disabilities or do not develop normally, with respect to weight and
length, do not usually fit into these child safety seats. If the child does not have
the normal motor and sensory functions, or has anomalies such as absence of one
limb or part of it, the common design of the child safety seat cannot provide safe
transportation for these children. Thus, these children are restricted to transport in
their wheelchairs, sulkies or in tailor-made seating devices. Hence, the
development of child safety seats for the target group of this study does not
correspond to the demands. Nevertheless, parents and professionals are expected
to transport children with disabilities to schools and developmental facilities on a
daily basis despite the limitations in the standards and the lack of information and
equipment options (Stout-Everly et al., 1993).
To be transported in wheelchairs, sulkies or in tailor-made seating devices
means that the disabled child has to enter the vehicle while remaining seated in
some sort of technical aid. These technical aids are usually constructed to
optimize seating and manual transportation, but little attention has been paid to
reducing the collision impact in the event of a crash during in-vehicle
transportation. Some wheelchairs and buggies have seat belts to improve postural
support, and these may be designed for restraining a user’s weight at normal
walking speed. However, these belts are not designed to restrain collision forces
of 40–60 G, as required in the Euro NCAP crash test standard. Manufacturers of
child safety seats do not develop and test their products, with the target group for
this study as users, in a test such as the Euro NCAP test.
There is a lack of knowledge concerning biomechanical aspects for the group
of children with disabilities. Anthropomorphic Test Devices (ATD), i.e. crash test
dummies, has not been developed in accordance with the demands of the target
group. The problem of poor compatibility between the need for safe road
transportation and the use of technical aids and special seating devices for
children with disabilities needs be subjected to future research.
4.8.2
Regulations and standards
The current amendment 3 of ECE Regulation 44 (Economic Commission for
Europe, 1998), ECE R. 44/03, does allow certain “Special needs restraints”. ECE
R 44/03 section 7.1.4.1.7 states that “In the case of a ”Special Needs Restraint”,
every dynamic test specified by this Regulation for each mass group shall be
performed twice: first, using the primary means of restraint and second, with all
restraining devices in use. In these tests, special attention shall be given to the
requirements in paragraphs 6.2.3 and 6.2.4”. Despite the amendment No. 3,
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VTI rapport 489A
problems with issuing general approvals of individual adaptations have remained,
both formally and technically. An adaptation can be describes as a modification to
a product made on more than a temporary basis, hence it can be non-reversible.
In the UK, safety guidelines were introduced for transporting children in
special seats (Medical Devices Directorate, 1992). In Australia, standards AS/NZ
54 370 for transporting children with disabilities in motor vehicles were
introduced (Baker et al., 1998). When the AS/NZ 54 370-1996 was being
prepared, the committee recognized the fact that no two individuals with physical
disabilities were the same, so provision was made to try to safely accommodate
the majority of the consumers’ needs.
As illustrated in Table 2, certain countries have introduced standards for
transportation of wheelchairs in vehicles, including ISO 10542 (International
Organization for Standardization).
Table 2 Standards for vehicular transportation of wheelchairs and wheelchair
occupants in certain countries.
Country
All
Standard
ISO
Tiedown
ISO 10542 (1–5)
Wheelchair in vehicle
ISO 7176–19
Australia
European
Union
CEN
A 52942-1994
Refers to ISO
A 52942-1994
Refers to ISO
SAE J2249
ANSI WC/19
USA
Comments
Only informative, i.e. not
normative, until referred
to in national regulations
or by consumers.
Normative in Europe.
Important for Product
reliability.
Similar to ISO standards
For the transportation of wheelchair occupants in vehicles, several countries have
regulations or standards, which are listed below. The listing is mainly included to
illustrate the different types of regulations and standards, not to describe them in
detail.
Sweden, formerly 1978 TSVFS, 1978:9 1985:24, now SNRA, VVFS 1994:5
(Petzäll & Olsson, 1996). The U.K. has a consultative standard on the safety of
wheelchair users in buses. The USA (SAE-WTORS, 1997; ANSI/RESNA , 1997),
and Australia (Baker et al., 1998) do also have regulations or standards for
wheelchair occupants in vehicles. For most other countries this literature review
found nothing of this nature. An explanation may be that authorities were waiting
for the International ISO standards in these fields to be adopted. Those standards
are: ISO 7176-19 for transportation related requirements for wheelchairs that are
suitable for occupant seating during motor-vehicle transportation and ISO 10542
for the wheelchair tiedowns and occupant restraints systems, i.e. WTORS. A
tiedown can be described as a strap or mechanism that secures a child safety seat,
or a wheelchair in place in a motor vehicle.
For wheelchairs, the ISO 10542 part 1–5 standard (International Organization
for Standardization, 2003).will provide a good description for the use of tiedowns
and occupant restraints. Nevertheless, the final result will depend on the type of
wheelchair (the wheelchair should have been tested according to ISO standard
7176-19) and the choice of tiedown and restraint system. Furthermore, the type of
car and the quality of the mounting or anchor point are also crucial.
VTI rapport 489A
55
The ISO standard 10542 is designed for adults, but part 5 of the standard does
specify the requirements for children weighing more than 22 kg. For children
below that weight the standard suggests that they should be “transferred from
their wheelchairs to appropriate vehicle child safety seats”. As stated previously,
not all children with disabilities will fit in to the child safety seats approved and
available on the market. Hence, this remains a problem to be solved.
4.8.3
Travel habits
Generally, the literature did not provide much information on the extent of
transportation of children with disabilities. Furthermore, the material showed that
it was impossible to obtain information on weekend travel, which can be assumed
to differ from weekday travel. School attendance is compulsory in many countries
and, hence, journeys to and from school for disabled children older than six years
can be used to illustrate travel habits, which in turn provides information on the
extent of travel. The school situation for children with disabilities who travel by
car or bus while sitting in their special seats or wheelchairs has changed rapidly.
Thus, the need for transportation of persons with disabilities is increasingly being
accepted (Bluth & Rosenfeld, 1993), at the same time as the need for regulations
and standards in this field has been highlighted.
In the UK, 15 % of the school population receives free school transportation
(Thornthwaite & Pettitt, 1993). The main reason for free transportation was that
they lived more than 3.2 km, i.e. two miles, from the school. In the county of
Berkshire, 32 out of 11,500 pupils were transported in wheelchairs, i.e. 3 per
thousand of all the pupils transported to and from school. In the UK,
approximately 3 % of all schoolchildren have significant special needs (Hall,
1995). If these pupils alone are taken into account, the figure for pupils
transported in wheelchairs rises from 3 per thousand to 1.3 %. In a study
conducted in Victoria, Australia (Vale, 1995), 0.52 % of the whole population
aged 0–18 required special car restraints due to neurological conditions.
Unfortunately, this study did not provide data showing what type of seating
devices these persons used.
Due to the limited amount of data concerning the travel habits of children with
disabilities, two studies have been performed in Sweden. One concerned the travel
habits of children with locomotor disabilities (Falkmer & Gregersen, 2001) and
the other of children with autism spectrum disorders (Falkmer, Anund, Sörensen,
Falkmer, & Gerland, 2001). Both studies concerned transportation in the family
vehicles, i.e. normally cars, as well as school transportation and in the Special
Transport Systems, i.e. STS. Both school transportation and STS can be
performed by cars, predominantly taxis; or buses, predominantly small buses, i.e.
so called M2 buses. Due to the fact that these surveys did not report separate data
depending on whether or not it was a car or a bus the children travelled with, data
concerning possible travels with M2 buses may be part of this section of the
report. However, the vast majority of journeys for this particular group of children
were performed by cars and, hence, the studies are included in this section to
provide an overall picture of the children with disabilities in cars.
With respect to children with disabilities Falkmer and Gregersen (2001) found
that:
• Children with functional disabilities most likely represent the group
classified as "individuals with the least protection and highest susceptibility
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VTI rapport 489A
•
•
•
•
•
•
•
•
•
•
•
to violence”. In accordance with the "Vision Zero", they should thus be
taken as a determinative factor in designing the traffic system.
Children with functional disabilities who are obliged to travel in a technical
aid are transported in products designed for travel at walking pace. Special
seats (including internal belts for postural support) constitute in all
probability a safety risk in the event of a serious crash.
A survey of the transport situation for children with functional disabilities
showed that the majority of journeys were made in the family car.
The destinations were primarily day nurseries, recreational centres or
schools, paediatric clinic, leisure activities or medical care.
School transportation was used to a greater extent than the family car only
for journeys to and from school.
In many cases, the family car was not adapted to the functional disability of
the child.
Children were almost always transported facing forwards or backwards in
the vehicle rather than sideways.
Very few children were seated without restraint in the family car. Less than
15 % of the children travelled seated in the family car using some form of
technical aid. One in eight of the technical aids was not secured in the
vehicle. Corresponding figures were 42 % sitting in some form of technical
aid in school transportation, of which 1 in 20 was not secured in the vehicle,
and 46 % seated in some form of technical aid in the special transport
service (STS), of which 1 in 20 was not secured in the vehicle.
In school transportation, approximately three out of five (59 %) were
restrained with a safety belt. The corresponding figure for STS was
approximately two out of three (63 %).
Especially on journeys with STS and school transportation, many children
with locomotor disabilities travel with an increased risk of personal injury in
the event of an accident/incident, partly because adequate safety measures
have not been taken and partly because they form a group that is highly
vulnerable to violent impact.
Approximately two out of five children travelled alone in school
transportation and STS.
Approximately one parent in two was able to choose alternative transport.
Increased freedom of choice correlated only weakly with increased
population density in the home area.
In the above summarised investigation (Falkmer & Gregersen, 2001), only 2 % of
the children had autism spectrum disorders,
Children with autism spectrum disorders are expected to be transported by their
parents or by school transportation and STS on a daily basis, in order to attend
school and day care centres, play with friends and perform leisure activities. This
implies that children with autism spectrum disorders are exposed to the inherent
risks connected with road vehicle transportation and in their special case, an
increased risk. The reason for this statement is that it can be anticipated that for
many of those children, being restrained by a safety belt and riding with unknown
drivers and passengers may cause ‘emotional behavioural problems’, if
approached inadequately. This, in turn, may lead to refusal to accept normal
safety precautions during the ride, due to qualitative impairment in reciprocal
VTI rapport 489A
57
social interaction, communication and imaginative activity, as well as to a
restricted repertoire of activities and interests (American Psychiatric Association,
1994; Wing & Gould, 1979), ‘‘…. behaviour found to be specific and universal to
autism’’ (Happé, 1996 p.18). Furthermore, children with autism spectrum
disorders can be expected to have an increased need for transportation compared
with non- disabled children, due to a lack of cognitive skills which hinders free
mobility even on short journeys, combined with an increased need for additional
health care treatment, i.e. more frequent travel compared with non-disabled
children. Thus, it was considered essential to map their travel habits as well.
Falkmer et al. (2001) found that a majority of the children with autism
spectrum disorders, i.e. 63 %, utilised school transportation. This was not the case
for STS, utilised only by every fourth child. One of the reasons for this could be
that the person administering STS grants has a problem in fully understanding the
mobility limitations caused by autism-spectrum disorders.
The journeys in school transportation usually took at least 10 minutes. Every
second journey took more than 20 minutes. During such trips it is natural that the
children ought to utilise recommended safety equipment, which proved not to be
the case. Infants up to the age of 3–4 are recommended to be transported facing
rearwards. In the present study, however, only one out of ten children in this age
group was transported this way. Moreover, safety belt usage in school
transportation and STS was low. Every seventh child in school transportation and
every eight child in STS travelled totally unrestrained.
Even in some cases where safety belts were used, the children faced an
increased risk in case of an impact. Of the children using the three-point safety
belt, i.e. a combined sash belt and lap belt, 7 % travelled with the sash belt part
under the arm instead of on the shoulder, a misuse that can prove to be fatal in
case of an impact. Furthermore, another 5 % were only restrained by a lap belt or
not restrained at all, indicating that in total 12 % of the children with autismspectrum disorders travelled under reduced safety in case of an impact.
The journeys in the family vehicle, which constituted the vast majority of the
children’s journeys, were, however, the safest mode of transport with regard to the
above-mentioned aspects. Transport mobility, being a crucial part of attending
school and day care centres, playing with friends and performing leisure activities,
is of vital interest for all children, regardless of whether the child is disabled or
not. The results from the study of children with autism spectrum disorders show
that they suffer from reduced transport mobility. The reason for this was found to
be that the transport system was not adapted to the special needs of children with
autism-spectrum disorders. Such adaptations would require drivers and other
professionals involved in the transport situation to implement an approach
towards the child, based on the knowledge of the communication problems
involved in autism-spectrum disorders. Children with autism-spectrum disorders
encounter problems in communicating with unfamiliar drivers, as well as with
unknown passengers. For this reason it was unsatisfactory to notice that as many
as every third child in school transportation travels with an unknown driver, at
least once a week. In STS every fourth child travelled with an unknown driver, at
least once a week. In many cases Optimisation of Travel Capacity (OTC) was in
use, which means that not only unfamiliar drivers could be expected but also
unknown passengers. The less populated the residential area the more frequent
was the OTC system. The parents stated that the children were affected negatively
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by the OTC system. More than half of the parents expressed that their child with
autism-spectrum disorder suffers from reduced transport mobility.
4.8.4
Transport providers
The literature review provided information on several executive producers of
transportation for children with disabilities who were restricted to transport in
their wheelchairs or special seating systems. Authorities responsible for
transportation to and from school, kindergarten and day care centers were
mentioned in several sources (Bull, Bruner-Stroup, & Doll, 1991; Hobson, 1996;
Kahdikar & Will, 1980; Rutenberg, Rhodes, & Smith, 1998; Shaw, 1987).
Parents as the executive producers of transportation were also mentioned in
several sources (e.g. Bull et al., 1991; Bull, 1989; Bull, 1991; Bull, 1996;
Dejeammes, 1998), as were health care providers (e.g. Paley, Walker, Cromwell,
& Enlow, 1993). However, the extent of their provision of transportation could
not be determined from the literature.
In Sweden, it can be assumed that families are the dominating executive
producers of transportation for children with disabilities. This is due to the vehicle
grants available in Sweden (Loman, 1996; SOU, 1994), which encourages the use
of a family vehicle for transportation. The systems are fairly similar in the three
countries.
4.8.5
Transport procedures
Most literature concerning transport procedures related to wheelchair and safety
restraint measures offered by professional transport providers. In a study in the
UK (Thornthwaite & Pettitt, 1993), a survey of local authority practice in
transporting children in wheelchairs was carried out in 1988/89. It was found that
the method of securing the wheelchairs varied widely. The survey highlighted the
problems of securing electric wheelchairs and their occupants. It was found that
28 % used only harnesses, i.e. a restraint system containing more than three
anchor points and designed to pass over the occupant’s pelvis and shoulders, and
12 % only lap belts.. Other terms with similar meaning are 4, 5, or 6-point
restraints or belts. Two of the authorities admitted that some wheelchairs were not
restrained and one of the authorities said that although all the wheelchairs were
secured to the vehicle, about 70 % of the children were not restrained at all in
their wheelchairs. The survey also found that half (25) of the responding
authorities had had accidents transporting children in wheelchairs during the
previous five years. Whilst most of the injuries sustained were classified as minor,
eleven of the 25 authorities reported that accidents had resulted in a change of
policy. The survey also found that six of the authorities (12 %) could not even
provide figures on the number of children transported in wheelchairs on a daily
basis.
In an American study (Stout-Everly et al., 1993), covering 285 transport
providers in the public school systems in Iowa and Indiana, reports on occupant
restraints for transporting children in wheelchairs presented the results in Figure 6.
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59
Lap shoulder belt
7%
Others (i. e. boosters, STC,
orthokinetic etc,)
14%
Seat belt
29%
E-Z on vest
9%
Front facing wheelchair
9%
Side facing wheelchair
18%
Tumble forms
2%
Car seat
12%
Figure 6 Types of restraint used by 285 transportation providers of the public
school system in Iowa and Indiana, USA, from Stout-Everly et al. (1993)
At least 61 % were transported in an unsafe way. This includes side-facing
wheelchairs, – occupied wheelchairs should never be transported sideways
(Kahdikar & Will, 1980), – in ordinary car seats, i.e. without using safety belts, in
seat belts, in “others” according to the classification used by the authors, i.e.
probably supplementary postural supports (i.e. an unknown part of 14 %), and in
tumble forms. Postural supports can be described as seat components or lengths of
webbing used to support a person in a desired position in a seating system (i.e. to
prevent the person from falling out during normal conditions). A postural support
is usually not designed or intended to provide occupant restraint in a vehicle
impact. Postural supports are not child safety seats and therefore cannot be
considered safe.
Safe methods of transport in this study were found for 39 %, at most. This
figure includes front-facing wheelchairs with the safety belt in use, E-Z-on vests,
i.e. a type of harness, lap shoulder belts, and boosters for children less than
150 cm tall or weighing less than 35 kg, in the category of “others”, i.e. an
unknown part of 14 %.
In the American study (Stout-Everly et al., 1993) frequent problems were
identified when schools, rehabilitation facilities and community agencies
attempted transportation for their clients with disabilities aged from birth to
21 years. Children's size, disability differences and vehicle differences affected
the safe transportation needs. For example, children weighing more than 22.7 kg,
i.e. 50 lb., were no longer able to use a child safety seat, even though they could
not ride unsupported on a bus seat. Survey respondents recognized this as a
special need because there was no Federal Motor Vehicle Safety Standard
(FMVSS) in the USA for equipment for children weighing more than 22.7 kg.
Original equipment manufacturers therefore had no specific federal standards for
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crash test durability and head and knee excursion limits for equipment for these
larger children.
4.8.6
Perceived risks and safety problems according to parents
and drivers
Several sources were found in the literature concerning perceived risks and safety
problems according to parents and drivers. One study from Victoria, Australia
(Vale, 1995) had used a questionnaire-based parental survey of transport problems
for the target group of this study. Maintenance of head control was found to be a
problem for all age ranges, as was not sitting straight and arching out of the seat.
The restraints were reported as being uncomfortable on both long trips and
short trips. A need for special installation, i.e. the process of permanently
fastening the wheelchair tie down and occupant restraint assembly to the vehicle,
was reported more for the 8 years and older group. This reflects the greater use of
special restraints and wheelchairs by this age range. A little less than half of those
responding to these sections of the questionnaire reported no problems with the
car restraints they used.
This result was in contrast with the findings in the American study (StoutEverly et al., 1993). The problems the transport providers experienced were:
• Emotional behavioral problems (51 %)
• Children resist applying of restraint system (32 %)
• Additional personnel needed to assist (31 %)
• Cost of securing appropriate equipment (23 %)
• Children unable to use standard safety belt or child safety seat (21 %)
• No adequate restraint (19 %)
• Difficulty securing wheelchair (16 %)
• Lack of information about the equipment (16 %)
• Driver unable to assist (15 %)
Both these studies (Stout-Everly et al., 1993; Vale, 1995) asked the respondents to
suggest improvements. The Australian parents suggested improvement of the
trunk support (15 %), improvement of the harness for ease of application and
comfort (15 %) and improvement of head support (14 %). The American transport
providers suggested improvement of the head/neck support (24 %), regulations
(FMVSS) for children weighing over 22.7 kg (17 %), and improvement of trunk
support (10 %).
The demand for regulations in the USA was supported by Paley et al. (1993).
By using a subjective safety score, from 0 (unsafe) to 10 (safe), they evaluated
63 children with disabilities in their family or agency vehicles. The mean safety
score was 1.6, with no child achieving a score higher than 6. They found no
significant differences in the scores of children transported by their families and
those transported by agencies.
In the same study the seating devices were scrutinized. Of the 62 customized
seating systems used in transportation at some point, 56 (90 %) were available for
inspection. Only six were models that had been crash tested and earned FMVSS
213 approval. Furthermore, the transport situation was examined. Unsafe
transportation was reported for 51 % of at-home transportation, for 60 % of
transportation to school and for 48 % of transportation to hospital. Unsafe seating
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61
was identified in 54 % of those taken to school – by school transport vehicles,
with the most common unsafe practice being use of the side-facing position.
In another American study, an observation checklist was developed based on
safety principles for wheelchair restraints (DiGaudio & Msall, 1991).
Observations of the subjects were made as they were transported by their families
or agencies to a residential summer camp, a pre-school program for children with
developmental disabilities, and a school for children with cerebral palsy, (CP). A
safety score system was developed based on laboratory studies conducted on
wheelchair restraint systems. This observation tool described the position of the
wheelchair in the vehicle, the occupant restraint system, and the wheelchair
restraint system. These structured observations revealed inadequate safety
measures, such as side facing wheelchair transport positions, and no or inadequate
restraining of both the wheelchair and the passenger riding in it. Comparisons of
safety scores of subjects transported by families with those transported by
agencies were not found to contain statistically significant differences.
The parents’ worries were studied in Sweden, both for children with locomotor
disabilities (Falkmer & Gregersen, 2002) and for children with autism spectrum
disorders (Falkmer et al. 2001) from a parental viewpoint, what subjective risks
the parents perceive and what safety problems the children experience, in addition
to the parents’ knowledge about the existing regulations and standards concerning
transportation.
Concerning children with locomotor disabilities, Falkmer and Gregersen
(2002) found that:
• Parents were often worried when the child travelled alone with an unknown
driver.
• Parents were worried about the child entering and exiting the vehicle and
also about the journey itself.
• In many cases, the mother or father lifted and carried the child by hand,
regardless of its age, which in turn caused worries.
• Worry about an accident/incident when entering/exiting the vehicle was
greater the younger the child, regardless of whether the worry was due to
the risk of the child or the parent being involved in an accident/incident.
• Some parents felt confused by different rules and authorities governing the
provision of technical aids and transport for families.
• The attitude to optimisation of travel capacity (OTC) in school
transportation and STS was more positive than expected, particularly in
sparsely populated areas. In the cities, somewhat more than 50 % were
negative to OTC.
• The rules governing transport in a family car and other transport means
were considered diffuse. Approximately half the parents had no knowledge
of the rules applying to transport (49 %) and STS (55 %). The
corresponding figure for transport by family car was 27 %.
Concerning children with autism spectrum disorders Falkmer et al. (2001) found
that the parents were mostly worried about drivers and other passengers being
unaware of how to approach and communicate with the children. They were also
worried that the drivers and other passengers were disturbed by the children, and
vice versa, both conditions being negative for the child. Furthermore, the parents
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were worried about their children manipulating the safety belt and thereby
eliminating its function.
One conclusion was that the younger the child, the greater the worry among the
parents. The transportation situation for children with Asperger’s syndrome
caused less worry than for children with other autism-spectrum disorders.
Moreover, children who had “Medical problems” and “Communication
problems”, according to a sub classification of the children’s additional
disabilities, caused more worries among the parents than children with other types
of additional disabilities.
Despite the worries experienced by the parents they thought that the children in
general appreciated the journeys in the family vehicle, as well as in school
transportation and STS. Also the postural positions of the children in the vehicles
were regarded as acceptable.
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63
5
Conclusions and discussion
5.1
Legal aspects
Within this study we have been looking in detail at the legal aspects concerning
children travelling as passengers in a car. If we compare existing laws in Sweden,
the USA, the U.K., and Australia it is obvious that there are quite big differences
between the countries. The outcome of how the parents/drivers are protecting their
children does not always depend on the law. There are also recommendations for
how to protect the child passengers. These recommendations are more detailed
and will often increase child safety a little more than the law demands. In all these
countries there are both laws and recommendations concerning child safety. One
way of improving child safety could be to have laws and recommendations that
are more consistent e.g. rearward facing and the use of booster seat. This is not the
situation today.
Age, length or weight
There are differences in the existing laws between the countries regarding the
criteria concerning children. Sometimes the criteria are based on the age of the
child (e.g. Sweden and Australia) and sometimes the criteria are based both on
age, weight or length of the child (e.g. the U.K. and the USA). In these four
countries it is mandatory to use safety belts both in the front and rear seat. Apart
from this, the law in each country demands that CRS are used. When the child is
at a certain age e.g. less than 7 years old in Sweden, and less than 4 years old in
the USA, the child has to use a CRS according to the law.
Where to be seated
There are also differences between the countries regarding where in the vehicle
the child is permitted to be carried. Different types of CRS are required depending
on where the child is carried. For example, in the U.K. there are differences in
what the law demands depending on whether the child is carried at the front seat
or back seat. In Sweden the law does not prescribe front or rear seat position. The
result from this review shows the importance of CRS for transportation safety,
especially for the youngest children, no matter where in the car they are
transported.
Rearward facing
As far as we can see, the law in the countries in this review does not prescribe in
what position the child has to be transported, i.e. if the child is seated forward
facing or rearward facing. In most of the countries there are also differences
between the law and the official recommendations. In most countries infants are
recommended to travel rearward-facing, but there are no rearward-facing seats
available for toddlers. In Sweden, however, rearward-facing restraint systems are
commonly used for both toddlers and infants, and are recommended to be used as
long as possible. Even children who are 4–5 years old are recommended to use
those seats.
The responsible person
According to the law, the driver is responsible for restraining children travelling
in the car but there are differences between the definitions of a child, with respect
to this legislation. In Sweden, the driver is responsible until the child turns 15. In
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the U.K., the driver is responsible for children below the age of 14. In Australia,
the corresponding age is 16. The question is why there are differences and what is
the relevance of the different key ages? No comparison with respect to these
questions has been made and, hence, these questions remain unsolved and a
challenge for future research.
5.2
Traffic fatalities and
international scene
serious
injuries
on
the
Data for 2002 were compiled. However, data with one-year age groups is often
not published which is unfortunate since the usage of CRS types and exposure
rates is likely to vary greatly between children of different ages. It is especially
important to split the age group 0–5 years. Moreover, provision of exposure data
for children is an international challenge. The situation now is that, in fact, we are
comparing different countries without having the opportunity to take exposure
data into account. Other factors that may influence the injury risk for children are
the age and crash worthiness of the vehicle in which children travel and the
proportions of heavy vehicles in the different countries. This implies that the
results shown in this section of the review should be read with great care. No
generalisations should be made. One important conclusion from this literature
survey is therefore that more exposure data is needed so that correct conclusions
may be drawn regarding accidents relating to exposure, i.e. the travel patterns of
children of different age cohorts.
5.3
Car development, installation systems and its
implication for child safety
Children should never be placed in front of an airbag that aims to protect adults.
The recent introduction of passenger side airbags has therefore made the issue of
transporting children more complicated, i.e. were can you safely place a child in
the car equipped with side airbags, airbag curtains etc.? One way to avoid the
problem is to always place children in the rear seat. However, this solution is not
always possible and it is not necessarily the best option from a safety perspective.
For example, one main reason for graduation from rearward facing restraints is
that there is not enough space for the legs of the child. This problem usually
occurs earlier for children seated in the rear (Krafft, 2002). It is thus important to
address the question of how to deactivate the airbag. The best alternative would
probably be a technical solution that automatically deactivates the airbag when a
child restraint is installed on the seat. The results from a Swedish survey showed
that two of the participating manufacturers offer such a solution (Forsman,
Hellsten & Falkmer, 2003). However, the technical design differs between the
manufacturers and the system only works with child restraints especially
developed for that particular design. A general solution of the conflict between
children and airbags requires a standardised system for all cars and child
restraints. No such standardised system is being developed and, at present, the
choice is between permanent deactivation and installation of an on-off switch.
Both systems have advantages and disadvantages and there is no general
agreement on the best system. For example, Swedish authorities recommend
permanent deactivation while the U.S. regulation only permits on-off switches.
The disadvantages of the two deactivation strategies are related to the potential
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65
misuse. Two types of misuse can occur: (i) the airbag is deactivated when an adult
is using the seat or (ii) the airbag is activated when a child is using the seat.
Permanent deactivation prevents the second type of misuse but, on the other hand,
adults will always be unprotected when using the seat. Both types of misuse can
occur in a vehicle equipped with an on-off switch. Further investigations are
needed in order to compare the two deactivation strategies. Both the effect of the
misuse and the misuse rate must be elucidated. The effect of the misuse includes
the risk of a child being injured from a deploying airbag and the increase in risk of
an adult not being protected by an airbag.
It is indeed a drawback for child safety to find that the ISOFIX system has not
come into everyday usage for CRS. The initial work in this area was ahead of its
time, but the regulation of only approving ISOFIX mounted CRS in a particular
car model has the result that in practice original manufacturers of CRS have not
tested and got their products approved for ISOFIX. However, as noted previously
a change is about to come, so that CRS mounted by ISOFIX will eventually be
approved on a general basis. This will most certainly contribute to enhancement
of child safety in cars. Already in 1992 Berg & Gregersen (1992) conducted an
investigation showing that ISOFIX minimised incorrect mounting and parents
were willing to pay a fairly large amount of money for having the system in their
car.
From a technical aspect, the car occupant protection looks quite simple. The
impact forces need to be distributed over a large area of the body, over as long a
time as possible and distributed in such a way that body parts are exposed to equal
retardation, minimising shearing forces and internal breakage. Finally, sharp
edges must not come into contact with the car occupant. For children there is one
major complication, the size of the head. Children are not miniatures of adults,
and thus need specific restraint types. For the smallest children, the babies and
toddlers, the head might be as much as 25 % of the body weight, compared to
about 6–7 % for an average adult.
It is obvious that children are protected quite differently in the various
countries studied. The most significant difference is the rationale behind rearward
facing versus forward facing CRS. Countries with a generally high traffic safety
standard tend to demand by legislation specific and approved CRS and/or
otherwise mandatory seatbelt use. Most of these countries also demand or
recommend rearward facing CRS, at least during the first year of life
One hypothesis could be that due to the long history of using CRS in Sweden
this has been a promoter of child transportation safety; parents of today often have
a history of being restrained in a CRS themselves in their childhood, which of
course strengthens their belief in the necessity of using CRS (Wenäll, 2003).
While studying most of the articles in this material, it is obvious that the most
common comment is some kind of a recommendation promoting rearward facing
CRS, due to optimum crash protection, even though consideration is given to a lot
of different practical limitations and disadvantages in the field of use. Reviewed
statistics, although revealing and interesting, suffer somewhat from lack of data,
due to the (lucky) fact that in some countries very few children die in car
accidents. Thus the data are very sensitive to each and every accident. However,
the statistics seem to show that rearward facing CRS provide the best protection
and where children are turned forward facing at a certain age; this tends to be
noticeable as an increased risk in the statistics.
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The consequence of incorrect use of child restraints is not very well
documented. Various observation studies show a large number of misuses. But the
seriousness of misuse is graded very differently in the different studies. For
example, a child weighing 1–2 kilogram too much for the CRS is actually exposed
to the same risk as a child put facing forward in a CRS intended for rearward
facing use. Grading of risk factors is rare in the reviewed literature. Furthermore,
very few actual crash tests have been made. Some studies have investigated actual
accidents, but the material is limited to a few accidents. Studies show that certain
types of CRS are more exposed to misuse than others. Convertible CRS are
pointed out to be a group of CRS with a lot of misuse problems. Some studies
point out that the youngest children should travel rearward facing. Depending on
the originating country, the recommendation on age where it is possible to turn the
child around to forward facing varies from about 1 year of age up to about 4–5
years of age. As a summary, from a technical protection viewpoint most of the
reviewed literature strongly favours rearward facing CRS. When the child is
turned to be forward facing, the studies point out the importance of correct
installation and proper placing of the seat belts over the child’s body. Warnings
are issued for the use of lap belt only and improper positioning of both the lap belt
and the diagonal belt, which should both be over rigid skeleton parts of the body,
the lap belt as low as possible over the pelvis and the diagonal belt well up over
the rib cage.
What type of incorrect use is a real risk? The approval procedure ECE R.44/03
sets limits that sometimes are strictly formal, such as the weight limit, while in
real life these limits probably do not represent sharp limits between success and
failure. And the crash itself is not an event with plain go/no-go results. The effect
of a properly used CRS might just not be fatal or non-fatal, but the difference
between serious injuries and minor injuries. But it can be difficult for the victims
to interpret a serious injury as a success, even though a crash without a CRS or
with a misused CRS could easily have been a fatal accident instead. If a child is
short but somewhat heavy, just over the weight limit of a CRS, this might
formally be classified as a misuse, but the child will nevertheless probably gain a
lot of protection from that CRS. On the other hand, a child that is too tall for a
protective device is obviously at risk even though the weight is within the formal
weight limitations.
The reviewed literature is somewhat scattered. Most of them report very good
results for rearward facing CRS and issue warnings for different misuses. On the
other hand, very few actual tests with comparable data have been found. The
consequences are serious in a lot of accidents, even though CRS are used in a
proper way. Serious incorrect uses were found to be;
• Placing a small child forward facing, even though it is in a CRS that
formally can contain elderly children forward facing.
• Using a CRS, intended for rearward facing installation, forward facing. This
often results in severe force loading on the specific child at belt locations on
the body which are not suitable for loading. It is also a combination often
found with younger, i.e. smaller, children.
• Using a booster seat or a forward facing CRS (ECE R. 44/03 group 1
universal forward facing, with integral belts) as a rearward facing CRS.
These forward facing group 1 CRS seats do exist quite commonly on the
European market and are sold to parents who might believe that these are
VTI rapport 489A
67
tested and approved for rearward facing installation. This has been a
problem in Sweden several times during the past 4-5 years.
• Putting the seat belts incorrectly. Examples can be putting the diagonal belt
under the arm of forward facing children on booster seats, booster cushions
or just with the seat belt, often due to the fact that the child or the parents
are concerned about comfort or do believe that the diagonal belt placed
close to the throat might pose a risk. No such injuries were found in the
literature. Putting the diagonal belt behind the upper part of the body,
resulting in the child being only restrained by the lap part of the belt, is
another common misuse, equally dangerous. There is a high risk of
submarining, or sustaining other internal abdominal injuries.
• The most frightening misuse, even though such accidents have so far never
happened in Sweden, is the combination of rearward facing CRS and an
activated airbag. Both actual crash tests and real life have shown that this is
a fatal combination.
• A Canadian study reported an increased risk of ejection from the vehicle in
rollover crashes when a child is seated in forward facing CRS with shields.
Exceeding the actual CRS weight limit by half a kilo or so, under the
circumstances that all other demands are fulfilled, is probably not the most
dangerous thing to do. On the other hand, exceeding the height limit of a CRS is
not recommended. When the height is outgrown, the head protection capability of
any CRS rapidly decreases.
The three main consequences of incorrectly used CRS are found to be
increased risk of head and neck injury, increased risk of spinal cord trauma and
increased risk of internal injuries to the abdomen, mainly due to the risk of
pelvis/abdomen submarining or upper body jack-knife effect if the car seat belts
are not positioned correctly in a forward facing CRS.
Although it can be said that it is extremely important to use a CRS and to use it
as intended, the conclusion is that the largest risk is determined for those who are
not restrained by any means at all. Any protective CRS is better than none, but the
very best protection is obviously gained from an approved and correctly installed
CRS, preferably a rearward facing CRS, where the child is well within all
limitations of that CRS. But no CRS can guarantee a 100 % success in case of an
accident.
5.4
Data from accidents and crash test regarding child
safety seats
Only a handful of studies have been found which report actual accidents and the
corresponding outcome due to misuse. The one and only major misuse is no use at
all of CRS. Unrestrained children are the biggest problem worldwide. Most
studies are dealing with small numbers of children, from just five accidents up to
around 500. The studies are rather sensitive to the stochastic variation of
accidents. In the only large study, by Zweitzer, Rink, Corey & Goldsmith (2002),
33 % of the children were unrestrained and an additional 20 % were incorrectly
restrained. These data are coherent with the data from the Wenäll report (Wenäll,
2001), in which 33 % of fatally injured children in Sweden 1992–1997 were
unrestrained. Both studies thus support the conclusions that three point belts are
better than two point lap belts, that forward facing CRS are better than just the
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seat belt and that the rearward facing CRS is, by far, the most effective protective
device in case of a frontal impact, at least for younger children.
5.5
Use and misuse of restraints
Laws and recommendations together form a platform for the child occupant
safety. The level of restraint usage measures are in some way the level of safety
for the children.
A comparison between child restraint use in Australia, The U.K., the USA and
Sweden shows that although the level of usage differs between these countries,
the percentage of usage generally decreases with age. Self reported studies, as
well as observational studies, show similar results. With respect to child restraint
systems, the reported level of use also decreases with age and the differences
between age groups become even higher.
In Sweden and The U.K. the level of child restraint use among infants and
small children (toddlers) was at least 95 % in the front seat and approximately at
the same level in the rear. In the USA the usage is still increasing and the latest
report shows approximately the same level of use as Sweden and UK. In all these
countries, however, the level of restraint use among older children was
significantly lower than among younger children.
The level of misuse was, nevertheless, alarmingly high. Some of the studies
even reported a misuse level of 90 %. Serious examples of misuse were:
dangerous buckle crunching, where part of the buckle comes in direct contact with
the frame of the seat and may snap open in case of a crash; and rearward-facing
seats in front of an airbag.
Common misuses were, loose seat belts and harness straps, restraint devices
not adequately secured to the seat or incompatible with the car, wrong type of
child restraint system with respect to age, weight or height. Infants and toddlers
travelling forward-facing, shoulder belt behind the back or under the arm, harness
strap slot position below the level of the shoulder, bulky clothes, use of restraints
that have been recalled by the manufacturer, use of seats that have been involved
in a crash, use of too old seats, misuse of safety belt locking clip and harness
positioning clip, children climbing out of the restraints.
When studying rates of misuse, one should remember that systems where both
the seat and the child need to be secured, such as infant seats, convertible
restraints and rearward facing CRS for toddlers are more difficult to use. Only in
Sweden is the rearward facing child seat for toddlers is commonly used.
Even though many children use child restraint systems, the premature
graduation of children from child restraints to seat belt is a problem in more than
one country. Lack of knowledge among parents is one reason found.
An important finding in several studies is that parents and other caregivers
think that their child is correctly restrained, while observations actually show that
they are not. Several studies showed that children with parents who were seeking
or receiving information about car child safety had a lower level of misuse.
Several studies mention the need to increase the collaboration between
manufacturers of child restraints and cars. The readability of instructions is also
mentioned as one reason for misuse, while the reading level of the text in one
study exceeds the reading skills of most American consumers.
VTI rapport 489A
69
5.6
Measures for improvement – Campaigns
Received literature contained studies or descriptions of campaigns carried through
in Sweden, the USA and Australia. Searching on British internet pages resulted in
a campaign carried out in the U.K.
The aims of all campaigns were to decrease fatalities to children by increasing
seat belt use and use of child safety restraints. Not every campaign has measured
the fatalities and the usage of restraints prior to and following the campaign.
Instead there are measurements of the awareness of the activities in the campaign.
No campaign has been evaluated regarding long term effects. The result of the
campaign depends on the usage of the safety belt when the campaign started. Of
course the result was better when the usage of seat belt was low before the
campaign started than when the usage of safety belt was high.
Important interventions to increase use of restraints are primary enforcement
laws requiring use and enhanced enforcement programmes. Programmes
including distribution of child safety seats and education programmes including
hands-on training are also effective.
A campaign in Australia towards parents from three non-English speaking
communities showed no significant increase in child restraint usage. On the other
hand, the nation-wide “Buckle Up America” campaign, still going on, presents a
good result maybe because of its wide extension and great variety of activities.
5.7
Children with disabilities
The transport situation for children with disabilities was found to be complex and
insufficiently described in the international literature. The present review found
studies on lack of safety measures for the target group. These studies had different
focus, nationalities and methodologies, which makes generalization of the results
difficult. However, safety problems were identified in all of them. The
outstanding finding of the literature review was, however, the insufficient data
concerning travel habits, as well as parents’ opinions, of children with disabilities.
For these reasons the studies on the Swedish transport situation for children with
locomotor disabilities, as well as with autism spectrum disorders provided
essential data.
For the vast majority of Swedish journeys, the family vehicle was used both for
children with locomotor disabilities, and for children with autism spectrum
disorders. Most of the journeys occupied a substantial length of time. This implies
not only higher exposure to accident risks, but also a demand for comfortable
seating solutions. Furthermore, the demand for personal assistance is greater on
longer trips.
Although the vast majority of journeys were made in the family vehicle, less
than a third of all family vehicles were adapted for transporting children with
locomotor disabilities. The number of safety belt users in the family vehicle was
high. The corresponding figures for school transportation and Special Transport
Systems STS were, however, substantially lower.
Although the children were restrained in the family vehicle, some of the
technical aids and/or the seating devices were not. Almost one in eight of the
journeys in the family vehicle were made with the disabled child seated in some
form of technical aid. Among these technical aids, one in eight was not restrained
at all.
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VTI rapport 489A
In school transportation, more than four out of ten travelled seated in their
technical aids. Almost one in ten of these technical aids were not tied down. Less
than six out of ten used safety belts. These figures show that school transportation
in Sweden can be a very hazardous means of transport for children with
disabilities. One explanation for these extreme figures may be that some school
transportation vehicles are in fact ordinary buses registered for more than eight
passengers and thus not subjected to mandatory use of safety belts by the
passengers.
Although this argument does not apply to STS, the results of this study showed
that less than two out of three used safety belts when transported in STS. Almost
half of the journeys in STS were made with the child seated in a technical aid.
Almost one in ten of these technical aids was not tied down at all. These facts also
show that STS travel in Sweden can be another very hazardous means of
transport.
The anchoring procedures must be subjected to more thorough rules and
regulations. From a safety point of view, it is unsatisfactory that so many children
travel in their technical aids with no tie-down system in use. The school
transportation system must be compelled to use safety belts for children with
disabilities, preferably all children, since children seated in technical aids face an
even greater risk in the event of an impact than other children. Furthermore, the
results show that several of these technical aids were adapted in order to increase
postural support, which may have devastating consequences in a collision.
Many of the parents were worried about their children when they were
transported alone in school transportation or STS. Lack of information and
knowledge of the driver seemed to be one underlying reason for the parents’
worries. Comprehensive information, focused on the special needs of children
with disabilities in their transportation, would probably reduce the parents’
worries significantly. The target group for this information should be professional
drivers and the content should also address the safety aspects of tie down
procedures, as well as basic medical and psychological knowledge. In addition,
parents’ need of information regarding safety procedures for their children should
be fulfilled.
Children with autism spectrum disorders travel under reduced safety
conditions, a situation which is considered risky by their parents and, hence,
creates worry on their part among the parents. Transport adaptations to children
with autism spectrum disorders should not be limited to physical/mechanical
adaptations. Approximately two out of three children utilised school
transportation, while only one out of four was permitted to use STS. The safety
belt usage in school transportation and STS was low. Every seventh child in
school transportation and every eighth child in STS travelled totally unrestrained.
This suggests that transportation of children with autism spectrum disorders, in
school transportation and STS, is in fact a hazardous means of transportation.
Parents were mostly worried about drivers and other passengers being unaware
of how to approach and communicate with the children. They were also worried
that the drivers and other passengers were disturbed by the children, and vice
versa, both conditions being negative for the child. Furthermore, the parents were
worried about their children manipulating the safety belt and thereby eliminating
its function; the younger the child, the greater the worry among the parents. The
parents’ worries were justified by the fact that many of the children were not
transported according to general safety recommendations.
VTI rapport 489A
71
To summarize: for children with disabilities there is clearly a need to create
new regulations and standards or sharpen up and apply the present ones. Human
factors should be taken into account during the design of any such regulation or
standard, oriented towards children with disabilities (Joly, 1991). The reason is
that a standard or a regulation must be fine-tuned to the needs and practices of the
target group. On the one hand, if the standards or the regulations are too rigid,
then the mobility of children with disabilities may be reduced. On the other hand,
if the standards or the regulations are too lenient, then safety will be jeopardized.
In finding an acceptable balance between these conflicting viewpoints, the
importance of parents’ information and opinions cannot be overemphasized.
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6
Suggestions
development
for
future
research
and
The present literature review has pointed out certain areas and topics, in which
future research is needed in order to promote development of in-vehicle child
safety. In the following, a selection of these areas and topics is listed:
• Discrepancies in laws and recommendations were found within as well as
between the investigated countries. It is important to establish a consistency
and consensus, especially concerning rearward facing seats and the usage of
booster seat. When reference is made to studies within this area it is obvious
that children seated facing forward are exposed to much more devastating
forces in case of a crash than children facing rearwards. Historically, parents in
Sweden have been recommended to place their children facing rearwards at
least until the children reach the age of three. The result of this is a reduced
number of fatalities in the age cohorts of 0–2 years compared with countries
not recommending this, despite the fact that survey studies have shown that
almost one out of four Swedish children in the age younger than 3 year were
travelling facing forward. If also these children would travel facing rearwards,
a further reduction in the number of fatal or severely injured children is
possible. Hence, a potential for increased injury preventive measures could be
defined and tested. In view of the fact that legally children are allowed to travel
facing forwards regardless of age, but recommended to travel facing rearwards
up to the age of four or five, it is suggested that legislation consistent with the
recommendation should be implemented, and evaluated by a before/after study
focusing on the number of killed and injured children and the types of injuries
(i.e. the injury patterns).
• Reliable accident databases based on one year cohorts, CRS usage and
misuse/misconception and exposure measurements, in combination with more
specific analyses are necessary, in order to describe and compare the traffic
safety situation for children in different countries, utilising different CRS
during different ages. Furthermore, such databases are important for evaluation
of campaigns etc. For this reason, a first natural step would be to start with the
Swedish accident database.
• Compared with other countries included in the review, the usage of CRS in
Sweden is high. It is not realistic to expect that the result from a nation-wide
campaign should be as positive as in countries where usage of CRS is not so
common. Instead, we suggest campaigns directed towards special groups of
interest. More information will thus be needed about potential problems
regarding misuse within special groups. The campaigns should be combined
with qualified practical help from e.g. the retailers.
• A true challenge is to investigate and promote possibilities for the use of
rearward facing CRS for the age group 4–6 years, which would include a
feasibility study on how to adapt car interiors for this purpose.
VTI rapport 489A
73
• A major revision of the ECE Regulation 44 is expected within a few years. A
new generation of test dummies, new measurements and new acceptance
criteria are being developed. Side impact tests are discussed as well as different
rating systems for consumer information. Research about the feasibility of
these changes and their implication on the CRS market is necessary. There is
an obvious risk that the Swedish interest in continuing with rearward facing
CRS for toddlers will not be covered if Swedish researchers are not actively
involved in these developments.
• Multi-children CRS, CRS for buses, and ambulance usage is a field of research
and development yet to be covered. A natural first step would be to identify the
scope of the problem and in a second step to address it by developing products
according to the needs. The final step would be to evaluate the products with
respect to crash testing and field research.
•
Some years ago it was possible to rent or borrow CRS for Swedish infants.
The CRS was normally provided by the public health care system. This
improved the use of infant seats. Unfortunately this is not very common today.
As far as we know there are no explanations for the disappearance of this
opportunity. We suggest further investigation to find out if this still is a
potential improvement for child safety in cars.
One group of children that needs special considerations is children with
disabilities. The following objectives could facilitate equal rights to safe and
secure transport mobility for children with disabilities:
•
An increase in the government subsidies for vehicle adaptations, with respect
to parents with disabled children, in terms both of the number of grants and
their size
•
School transportation systems and STS must be compelled to use safety belts
for children and adolescents with disabilities, preferably for all passengers.
Furthermore, tie-down systems must be made compulsory for all road vehicle
transportation where technical aids or special seating devices are used for
seating in the vehicles.
•
An implementation of ISO standard 7176-19 for transportation related
requirements for wheelchairs that are suitable for occupant seating during
motor-vehicle transportation and ISO standard 10542 for wheelchair tiedowns
and occupant restraint systems into the daily work of transport providers and
technical aids centres. For wheelchairs, the ISO 10542 standard, part 1-5, will
provide a good description for the use of tiedowns and occupant restraints.
Nevertheless, the final result will depend on the type of wheelchair (the
wheelchair should have been tested according to ISO standard 7176-19) and
the choice of tiedown and restraint system. Furthermore, the type of car and
the quality of the mounting or anchor point are also crucial. The ISO standard
10542 is designed for adults, but part 5 of the standard specifies the
requirements for children weighing more than 22 kg. For children below that
weight the standard suggests that they should be “transferred from their
74
VTI rapport 489A
wheelchairs to appropriate vehicle child safety seats”. As stated previously,
not all children with disabilities will fit in to the child safety seats approved
and available on the market. Hence, safe transportation for disabled children,
weighing less than 22 kg, remains a problem.
•
A handbook, describing basic medical and psychological knowledge,
regulations and standards and safety aspects of transportation, which is
currently in production and will be a useful tool for professional drivers,
would probably reduce parents’ worries significantly. The implementation of
the handbook is an important issue, especially to particular groups of children
with different socio-economical backgrounds
A natural scientific approach to the above objectives is to evaluate the impact of
the suggested objectives, once they are achieved.
VTI rapport 489A
75
7
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84
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Appendix
Sid 1 (2)
Available statistics and sources
Australia
Available data:
Accidents:
Severity level:
Population:
Exposure:
Source:
One year groups 0–16 years, -98–01
Fatalities only
One year groups, -98–00
Not available.
http://www.atsb.gov.au/ Australian Transport Safety Bureau (accidents)
http://www.abs.gov.au/ The Australian Bureau of Statistics (population)
The U.K.
Available data:
Accidents:
Severity level:
Population:
Exposure:
Source:
One-year groups Killed/Killed or seriously injured/All
Killed/Killed or seriously injured/All
Estimates for groups >1, 1–4, 5–14
Distance travelled per year.
Trips per person per year
1998-2000 as one group. Under 17 as one group
Trips per person per year and age (one-year-groups)
available 1992–2000.
http://www.statistics.gov.uk/ National Statistics Online (population)
http://www.transtat.dft.gov.uk/roadsafe/index.htm Department for
Transport (accidents)
http://www.transtat.dft.gov.uk/personal/index.htm (exposure)
The USA
Available data:
Accidents:
Severity level:
Population:
Exposure:
Available for age groups 5–9, 10–15 and up. -98–01.
Fatalities only
for age groups 5–9, 10–14 and up. -98–00.
Not available.
All reports from fatal accidents are available with exact
age of victims.
Source:
http://www-fars.nhtsa.dot.gov/ Fatality Analysis Reporting System (FARS)
Web-Based Encyclopedia (accidents)
http://www.bts.gov/ The Bureau of Transportation Statistics (BTS)
http://www.transtats.bts.gov/Tables.asp?DB_ID=150&DB_Name=Census%
20Population%20Estimates BTS TranStats (population).
VTI rapport 489A
Appendix
Page 2 (2)
Sweden
Available data:
Accidents:
Severity level:
Population:
Exposure:
Source:
One-year groups available upon request
Killed, severely injured and slightly injured
One-year groups available
Age 0–5 not available
Average number of journeys/year and Average travelled
distance/day
Age 6–17 as one single group 2001 available (SIKA:s
årsbok 2003) Age 6–17 as one-year groups available upon
request 1998, 1999, 2000, 2001 from VTI etc (RES data).
This data was, however, not intended to be used as oneyear groups which gives very large uncertainties.
www.sika-institute.se Swedish Institute for Transport and Communications
Analysis (accidents)
www.scb.se Statistics Sweden (population)
VTI rapport 489A
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