| Passenger
Crash Protection in School Buses January
1999
In July 1998, the National Association of State Directors of Pupil Transportation
Services issued a Position Paper titled, "Passenger Crash Protection in Large
School Buses." Since then, a number of significant actions have taken place.
This updated Position Paper provides the latest information on passenger crash
protection in all sizes of school buses. Additionally,
Dr. Phyllis Agran, one of the authors of a scientific paper quoted in the July
1998 Position Paper, notified the Association of her objection to the manner in
which the paper was used in the Position Paper. Specifically, Dr. Agran noted
that permission was not obtained from either her or the American Academy of Pediatrics,
holder of the copyright. Furthermore, Dr. Agran noted that excerpts were taken
out of context, edited, and presented in a misleading manner to support the State
Directors Association's position against lap belts in large school buses. Dr.
Agran has made it clear that in no way does the article, "Child Occupant
Protection in Motor Vehicles," authored by her and her colleagues, suggest
that children would be better protected from occupant injury in school buses if
they were unrestrained, as is implied in the July 1998 Position Paper. It
was never the intention of the State Directors Association to violate any copyrights
or misstate, take out of context, or misrepresent the information contained in
Dr. Agran's scientific paper. The State Directors Association believes Dr. Agran's
paper is an excellent work, and regrets any misunderstandings that may have resulted
from the reference to her scientific paper in the July 1998 Position Paper. The
July 1998 version of this Position Paper should no longer be utilized. Page
2 Introduction
No one questions that school buses are the safest form of highway travel,
or that today's school buses provide students with exceptional levels of safety.
Despite these facts, the pupil transportation industry constantly is seeking ways
to make a safe form of transportation even safer. In this quest, there are times
when individuals and organizations will disagree over the potential benefits of
certain safety features. This paper provides a discussion of the current status
of passenger crash protection in school buses. It also provides comments from
safety experts and safety researchers on the appropriateness of lap belts as a
means of passenger crash protection for children. A Summary and Conclusions section
is presented first, followed by detailed discussions of the wide range of topics
and issues involved in the crash protection of children in school buses. The
State Directors Association believes it is important to define the terms that
are used in the debate over the best means of providing crash protection to children
in school buses. Unless terms that are consistent and unambiguous are used, there
may be confusion. Unfortunately, the term "seat belt" means different
things to different people. Rather
than using non-definitive terms such as "seat belt," precise terms should
be used to define the "belt system" under discussion - it is either
a "lap belt" or a "lap/shoulder belt." These terms are easily
and completely understood by everyone. Summary
and Conclusions School
buses are the safest form of motor vehicle travel in the United States. While
every serious injury or fatality to a student in a school bus is tragic, such
instances are few in number each year. Nationwide, on average there are fewer
than 10 school bus passenger fatalities each year out of approximately 10 billion
student trips. In contrast, more than 800 school-aged children are killed in passenger
cars or other private vehicles during normal school hours. It is likely that many
of these children were on their way to or from school or school-related activity.
In such instances, had these children been in a school bus, they would most likely
be alive today. Based
on all of the real-world facts, "compartmentalization" in today's school
buses is providing an extremely high level of crash protection for student passengers
considering all the types of crashes involving school buses. There are no aggregate
statistical data to suggest that a safety problem exists in large school buses
that the installation of lap belts would solve. In fact, there is growing concern
among safety professionals around the world over the use of lap belts as a form
of passenger restraint for young or small children. In August 1998, at a public
hearing held by the National Transportation Safety Board, five international experts
in the field of motor vehicle occupant crash protection expressed their concern
about the appropriateness of lap belts in providing crash protection to small
children. The unanimous opinion was that lap belts were not a good means of providing
crash protection to small children because small childrens' bone structure, particularly
their hips, is still developing through grade school. Page
3 In addition,
in November 1998, Mr. Jim Hall, Chairman of the National Transportation Safety
Board, spoke to a national conference of school transportation professionals.
In his remarks, Chairman Hall stated that, "I personally think it is our
turn now to step up to the plate on the issue of lap/shoulder belts in school
buses." He went on to state that while "we have to stop being indecisive
on this issue," we should "commit to doing it, but let's do it right."
Chairman Hall reiterated that "we have to make sure this is done on the basis
of solid science. We don't want to simply bolt in lap belts at every seating position."
Finally, Chairman Hall stated that "lap belts are probably not the most effective
form of restraint for the millions of children transported on school buses." A
number of scientific papers that assess the effects of lap belts and lap/shoulder
belts on children involved in real-world motor vehicle crashes have been conducted.
While these studies appear to be based exclusively on children in passenger cars
and other private vehicles, the conclusions of the studies raise important questions
with respect to the appropriateness of lap belts in school buses. For example,
the report, "Injuries to Children Restrained in 2- and 3-Point Belts,"
was presented at the 42nd Annual Proceedings of the Association for the Advancement
of Automotive Medicine in October 1998. While the authors of the study did not
draw any conclusions about the relative efficacy of lap belts versus lap/shoulder
belts, they did point out that "Injury risks to children restrained in 2-point
belts have been well described. 'Seat belt syndrome,' associated with the use
of 2-point belts, includes contusion of the abdominal wall, fracture of the lumbar
spine, and intra-abdominal injury." The
study concluded that, "Children restrained in 3-point belts exhibit a similar
pattern of injury to those in 2-point belts, however 3-point belts appear to be
protective for the lumbar spine." The authors of this study noted that while
it included data on more real-world crashes than previous studies of the effects
of 3-point lap/shoulder belts on children, it was still a relatively small study,
and excluded belted children who were uninjured in motor vehicle crashes. The
absence of data on children using lap or lap/shoulder belts who where uninjured
makes it impossible to draw any conclusions about the absolute or relative effectiveness
of lap or lap/shoulder belts on children. The
purpose of citing this study is not to suggest that the paper or the authors of
the paper believe children are better off unrestrained in motor vehicles. Rather,
studies such as this appear to indicate that all types of passenger crash protection
devices may have unique consequences for children. The State Directors Association
believes it is extremely important to understand the interaction of all types
of passenger crash protection devices on the human body. Much is learned through
epidemiological studies that are conducted by the medical community. If children
or adults are needlessly injured in real-world crashes, such studies can assist
in the identification of problems and the development of solutions to those problems. The
development of a better understanding of the types and causes of injuries occurring
to passengers in school buses can not be overstated. This information can only
be gathered from medical records, either from the hospital or physician that treated
the injured child. Without medical information on the type and severity of injury
being suffered by school bus passengers in various types of crashes, it is not
possible to properly evaluate the relative benefits of different forms of passenger
crash protection in terms of preventing or inflicting injuries to children in
school buses. Without data on how and when lap belts, or lap/shoulder belts, or
"compartmentalization" either Page
4 reduce the
risk of injury or cause an increased risk of injury to children on school buses,
it is inappropriate to suggest changes to current requirements for the crash protection
of school bus passengers. Some
have suggested that differences in seat design (such as the seat cushion stiffness)
between passenger cars and school buses reduce concerns about lap belt-induced
injuries to small children. The State Directors Association believes it is only
possible to determine the effect of seat designs on the relationship between lap
belts and the skeletal development of children through scientific evaluation,
including laboratory testing and evaluations of real-world crashes and medical
records. To that extent, in August 1998, the National Highway Traffic
Safety Administration (NHTSA) announced an extensive 2-year research program to
consider alternative methods for potentially improving Federal school bus passenger
crash protection requirements. In announcing the program, NHTSA reiterated its
belief that "compartmentalization" has proven to be an excellent form
of school bus passenger crash protection, but believes it is important to develop
the necessary data and science to review and evaluate objectively potential improvements
in passenger crash protection for the next generation of school buses. The NHTSA
research program is designed to determine whether it is technologically feasible
and operationally practicable to upgrade the current Federal standards for passenger
crash protection in school buses. The research approach is direct - develop data
on existing school bus crashes to determine the causes of fatalities and serious
injuries; use that data to evaluate existing and alternative passenger crash protection
systems in a laboratory test environment; and consider the impact of various passenger
crash protection systems on school bus capacity and emergency egress. Based on
the results of this research program, the data and science necessary for making
informed decisions about the safety of all children in school buses should be
available. Until
such time that the research and crash test data support alternative crash protection
systems, the State Directors Association continues to support the conclusions
reached during the past 20 years by the National Academy of Sciences and the National
Transportation Safety Board, and the position of the National Highway Traffic
Safety Administration, that there is no supportable need for lap belts in large
school buses. In addition, the State Directors Association believes that legislators
and regulators, in carrying out their responsibility to establish public policy
through laws and regulations, have an obligation to make decisions based on data
and science, not emotion and supposition. To do otherwise could result in public
policies that improperly use society's limited resources, and could result in
additional injuries and fatalities to school bus passengers, rather than reducing
or eliminating them. The
State Directors Association fully supports NHTSA's announced research program,
and believes it is the appropriate mechanism for resolving the current debate
about the appropriateness of lap belts in school buses, and to establish the foundation
for potential improvements to school bus safety. The State Directors Association
has provided suggestions to NHTSA on the scope and content of the research program,
and will, to the extent permitted, stay involved in the research program and its
results. The State Directors Association has already requested that NHTSA expand
the scope of its research program to include all sizes of school buses, based
on its concerns about the appropriateness of lap belts as a form of crash protection
for young children.
Page 5 The
State Directors Association believes that all interested parties should take an
active interest in the NHTSA research program, so as to insure that the program
addresses the appropriate issues, and that NHTSA is aware of all existing data
relative to pertinent issues involved in passenger crash protection in school
buses. Over the years, many studies of school bus transportation have noted that
there is a need for more and better data upon which to draw conclusions and make
decisions. The NHTSA research program should be structured to collect and analyze
the data needed to make informed public policy decisions about passenger crash
protection in school buses. Without complete data, there are no bases to support
changes to existing school bus safety requirements. The State Directors
Association believes it is inappropriate to consider legislation, at any level,
to require lap belts in school buses while the Federal government is conducting
research that is designed to develop the next generation of passenger crash protection
systems in school buses. Without attempting to prejudge the outcome of NHTSA's
research program, it does not appear that the agency would conclude that lap belts,
a 30-year-old technology, were the most effective form of passenger crash protection
for school buses for the next century. Rather, with the advancements that have
been made in lap/shoulder belt systems and energy absorbing materials and construction
techniques, it would appear that NHTSA would propose changes to school bus passenger
crash protection utilizing the latest technologies. While
the NHTSA research program is underway, the State Directors Association believes
that the pupil transportation industry, parents, state and local legislators,
and all other interested parties should join forces in an effort to reduce the
deaths and serious injuries to children that, either by choice or circumstance,
travel to and from school and school-related activities in private vehicles, in
vans that do not conform to Federal safety standards for school buses, in transit
vehicles, or who walk or ride bicycles. While there are no exact numbers available,
it is clear that hundreds of children are needlessly killed each year as they
travel to or from school or a school-related activity in some manner other than
a school bus. It is likely that the number of serious injuries to such children
is equally high. The State Directors Association believes the most prudent course
of action for the next two years is to address the safety issues of children not
in school buses. In addition, the safety of children as pedestrians in the school
bus loading zone must continue to be addressed. When the Federal government has
completed its research, then the focus should return to the best means of providing
passenger crash protection to children on school buses. As a final note,
the pupil transportation industry is made up of thousands of people who have the
safety of children as their highest priority. Most are parents, also. Whenever
there are devices or procedures which have the potential to make pupil transportation
even safer, the State Directors Association is at the forefront of the debate.
If a device or procedure proves to be beneficial based on all available data and
information, the State Directors Association stands ready to provide its support
to legislators and regulators. Page
6 Background and Related Information The
issue of whether to require "seat belts" in large school buses [those
with a gross vehicle weight rating over 10,000 pounds] is a topic that has been
studied thoroughly and debated for many years. An important, but often overlooked
fact in the debate, is the difference between lap belts and lap/shoulder belts.
Until recently, no one has advocated the installation of lap/shoulder belts in
large school buses. During the last year, school transportation organizations
have expressed their support for studies to determine the engineering feasibility
and operational practicability of installing and using lap/shoulder belts for
passengers of all ages and in all sizes of school buses. In addition, it is critical
to develop an understanding of the interaction of lap/shoulder belts on children
of all ages and sizes from a medical perspective. In
general, advocates for lap belts in school buses point to the potential benefits
of lap belts in terms of reduced injuries and fatalities in certain types of school
bus crashes -- typically side impact and rollover crashes. They also refer to
improvements in pupil behavior as the result of lap belt usage. Finally, advocates
point to the importance of consistency in teaching children to buckle-up in all
types of motor vehicles -- if there are no lap belts in school buses, advocates
believe there is an obvious break in the chain of consistency. Life,
however, is filled with numerous inconsistencies that young children and young
adults must face. How they face or deal with those inconsistencies depends on
how they are presented and explained by parents, highway safety officials, or
educators. Children, even the very young, have tremendous capacity to reason and
understand. For instance, children learn from infancy that adults are the rule
makers, authority figures, and should be obeyed. All their contacts with adults
(parents, grandparents, care givers, teachers) reinforce this teaching. However,
children are also taught at an early age that some adults are not to be obeyed,
such as strangers who offer gifts, auto rides, or attempt to touch children in
unacceptable ways. When
appropriately presented, children and young adults can understand that a school
bus and an automobile are very different in purpose, design, and construction.
And, they can understand that although a lap belt or a lap/shoulder belt are important
and appropriate for use while traveling in an automobile, light truck, or van,
the passive occupant safety system in school buses, "compartmentalization,"
is equally appropriate. Those
opposed to the installation of lap belts in large school buses point to a wide
variety of data and facts: (1) the safety record of school buses; (2) analyses
of all types of real-world school bus crashes; (3) laboratory crash test data;
and (4) the potential effects of lap belts on young children. It is important
to realize that lap belts only provide restraint around the hips of a seated individual.
Lap/shoulder belts, on the other hand, provide restraint around the hips and across
the upper torso of a seated individual. The
potential safety benefits of these two systems are very different. Lap belts,
even when properly positioned and tightened, allow full upper torso movement.
As a result, a person's head could contact surrounding surfaces at higher impact
velocities than if they were unbelted. Lap/shoulder belts restrain the upper torso
and, thereby, reduce the likelihood of head contact with a surrounding surface. Page
7 It has been
suggested that school buses that have wider seat spacing to accommodate the installation
of child safety seats will reduce the potential for head contact for passengers
utilizing lap belts. While the greater seat spacing would obviously reduce the
likelihood of head impacts, not all school buses would be constructed with child
safety seat anchorage systems and the resulting wider seat spacing. Additionally,
even in school buses that were equipped with child safety seat anchorage systems
and wider seat spacing, such anchorage systems and seat spacing would not necessarily
be at every row of seats in the school bus. Safety
Record of School Buses One
of the major reasons for the outstanding safety record of school buses is the
manner in which they are constructed. As is the case with all motor vehicles sold
in the United States, school buses have to meet a stringent series of Federal
motor vehicle safety standards designed to provide school bus passengers with
high levels of safety should a crash occur. One of those Federal standards,
"School Bus Passenger Seating and Crash Protection," establishes minimum
occupant crash protection requirements for school buses built after April 1, 1977.
For large school buses, the Federal standard requires occupant protection through
a concept called "compartmentalization" -- strong, well-padded, well-anchored,
high-backed, evenly-spaced seats. In
the late 1960's and early 1970's, research was conducted on how to best provide
passenger crash protection to the various sizes of children that ride school buses.
The research looked at alternative ways of reducing pupil injuries and fatalities
in school buses as they existed at that time. School buses of that era typically
had exposed metal seat frames and grab bars on the top of the seats, and the seats
had little or no crash energy management or energy absorption capabilities. Some
of the research suggested that improvements in seat structure and energy absorbing
padding, along with the installation of lap belts, were needed to improve the
safety of children in school buses. However, there were other data and factors
that had to be considered in establishing the Federal standards governing school
bus construction. One of the most relevant dealt with concerns about whether lap
belts would be used. No type of restraint device provides a benefit unless the
vehicle occupant actively connects the belts. In
the mid 1970's when the Federal school bus standards where being developed, only
a small percentage of occupants in all types of vehicles used the available belt
system. This fact suggested that the usage rate of lap belts in large school buses
would be equally low. No state or jurisdiction had mandatory belt use laws, as
currently exist. As a result, the Federal government looked to a "passive"
means of providing passenger crash protection in school buses. A "passive"
crash protection requires no action by the vehicle occupant to attain the benefits
of the system. For example, air bags, motorized lap/shoulder belt systems, and
interior padding require no action by the vehicle occupant to obtain the benefits
of the system. The inherent benefits of a "passive" crash protection
system versus an "active" crash protection system are important. First,
the benefits of a "passive" system are always there, and require no
action by the vehicle occupant. Second, "passive" crash protection systems,
particularly those that utilize energy-absorbing structures and padding, provide
protection to different sizes of occupants and in various seating positions. The
"compartmentalization" concept for passenger crash protection in school
buses is a passive crash protection system. Page
8 It must be recognized that the research conducted in the 1960's
and 1970's was done on school buses that did not meet the safety requirements
of modern school buses, those manufactured since April 1, 1977. Thus, it would
be inappropriate to consider the results of those tests with respect to the potential
effectiveness of lap belts in school buses that meet current Federal safety standards.
The crash performance and interior design features of school buses built prior
to April 1, 1977, are not comparable to school buses built after that date. The
effectiveness of "compartmentalization" has been confirmed in independent
studies by the National Transportation Safety Board and the National Academy of
Sciences. National
Transportation Safety Board (Safety Board) In 1987, the Safety Board
completed detailed analyses of 43 serious accidents involving large school buses
to evaluate the effectiveness of "compartmentalization."1 These crashes
included frontal and side impacts, and included a large number of rollover crashes.
A Safety Board team of accident investigators reconstructed each crash, evaluated
the motion of the occupants, and identified the cause(s) of the injuries/fatalities.
For each crash, an evaluation was made of whether the use of lap belts would have
made a difference in the injury levels of the school bus occupants. From
a public policy perspective, the Safety Board's conclusions are extremely important.
-
School bus occupant
deaths and the serious or worse injuries sustained by survivors were, for the
most part, attributable to the occupants' seating position being in direct line
with the crash forces. It is unlikely that the availability of any type of restraint
would have improved their injury outcome. -
Lap
belt use probably would have made no change in the total number of school bus
passengers who died in the crashes investigated ... possibly one more death would
have resulted. -
Lap
belt use probably would have made no change in the number of surviving school
bus passengers with severe or worse injuries. -
At
best, lap belt use probably would have reduced somewhat the injuries of less than
8 of the 24 surviving school bus passengers with serious injuries. At worst, seat
belts might have increased the injury to almost as many passengers with serious
injuries as it improved. -
Lap
belt use probably would have worsened the outcome for one-fifth [20%] of the 58
school bus passengers with moderate injuries. _________ 1
"Crashworthiness of Large Poststandard Schoolbuses," National Transportation
Safety Board, Report Number NTSB/SS-87/01, March 18, 1987. This study was designed
to evaluate the effectiveness of the Federal requirements for "compartmentalization"
under FMVSS No. 222. As such, it only compared the post-1977 school buses with
pre-1977 school buses that were built to Federal requirements. Since there were
no Federal requirements for lap belts on either pre-1977 school buses or post-1977
large school buses, it would have been inappropriate to include any crashes involving
school buses equipped with lap-belts in this study. Page
9 These real-world data clearly show that while lap belts may offer
a safety benefit in some instances, in most crashes the installation and use of
lap belts would not have changed the injury outcome of the crash. Equally important
is the fact that in a significant number of crashes the use of lap belts would
have worsened the injury levels. In fact, it appears that in one instance the
use of lap belts would have killed a child that would have otherwise survived.
When all crashes are considered, it appears from the data that there are no overall
benefits of lap belts in large school buses. Since
the Safety Board's study was completed in 1987, there have been a number of school
bus crashes that have resulted in fatalities and serious injuries. While each
of these crashes and the consequences are tragic, it is important to study such
crashes to identify areas for potential safety improvements. Three of the most
tragic crashes occurred in Carrollton, Kentucky; Alton, Texas; and Fox River Grove,
Illinois. In Carrollton,
27 occupants of a former school bus died due to fire and smoke inhalation. In
Alton, 21 students drowned in a bus that rolled on its side and was totally submerged
in water. And, in Fox River Grove, 7 students were killed when their bus was struck
by a speeding train. Each of these crashes required immediate, quick action by
passengers under extreme conditions, in order to survive. In Carrollton, a gasoline-fed
fire spread rapidly through the bus, and provided very little time for evacuation
of the crowded bus. In the Alton crash, the Safety Board's investigation report
notes that there "was inadequate time for 81 desperate students to escape
through the available window openings and rear emergency door. ... Escape was
further complicated by dark murky water which obscured vision. ... The 21 students
who perished did not have enough time to escape from the bus." In Fox River
Grove, the students sitting in the back of the bus saw the train approaching and
had only fractions of a second to move from the back of the bus to the front.
In each of these crashes, unlatching lap belts would have required additional
time under panic conditions. In Carrollton, the passengers, many of whom were
sleeping, were first stunned by a head-on crash with a pickup truck at a speed
of over 100 miles per hour, and then had to cope with fire and dense smoke in
an effort to escape the burning bus. No one died from trauma-induced injuries.
In Alton, the bus was struck by a tractor-trailer, then plunged from a cliff into
water, and the students had to escape in murky water while the bus was on its
side. Any passengers on the right side of the bus would have been hanging from
their seats by the lap belts. Again, no one died as a result of trauma-induced
injuries. In Fox River Grove, all of the students in the back of the bus had only
milliseconds to get out of their seats and run forward prior to the collision. There
is little doubt that the installation and use of lap belts in these crashes would
have resulted in additional fatalities and serious injuries. This fact must be
considered in any debate over the potential benefits of lap belts in school buses.
Unfortunately, these crashes often are ignored by those who advocate the installation
of lap belts in school buses. Instead, advocates for lap belts in school buses
tend to base their arguments on selected crashes. For example, a 1996 rollover
crash of a school bus in Flagstaff, Arizona, which resulted in five students being
ejected from the bus, one of whom suffered serious permanent injuries. Of the
26 other students in the school bus, one also suffered serious permanent injuries.
Like all fatalities and injuries to children, these injuries are tragic and everyone
wishes they had never happened. However, in making public policy decisions, it
is imperative to consider all information on a subject, not just data from selected
crashes. Page
10 As stated
earlier, there have been school bus crashes where lap belts may have offered a
safety benefit. However, there are other crashes where the installation and use
of lap belts would have resulted in more injuries and fatalities. When the entire
range of school bus crashes are considered, the State Directors Association does
not believe there is a compelling body of data to support the installation of
lap belts in large school buses. National
Academy of Sciences In
1989, the National Academy of Sciences completed a study at the direction of the
United States Congress on "the principal causes of fatalities and injuries
to school children riding in school buses and of the use of seat [lap] belts in
school buses and other measures that may improve the safety of school bus transportation."
The Academy was directed to "determine those safety measures that are most
effective in protecting the safety of school children while boarding, leaving,
and riding in school buses." In its conclusions, the Academy noted that "the
overall potential benefits of requiring safety [lap] belts on large school buses
are insufficient to justify a Federal requirement for mandatory installation.
Funds used to purchase and maintain seat [lap] belts might be better spent on
other school bus safety programs and devices that could save more lives and reduce
more injuries." The Academy pointed out that since children are at greater
risk of being killed in the school bus loading zone (i.e., while boarding or leaving
the bus) than as a passenger in the school bus, "a larger share of the school
bus safety effort should be directed to improving the safety of school bus loading
zones."2 One
of the often cited conclusions from the Academy's study is that "seat (lap)
belts, when properly used on post-1977 ... school buses, may reduce the likelihood
of death or injury to passengers involved in school bus crashes by up to 20 percent."
That estimate was based on a 1986 study of rear seat occupants in passenger cars,
only a small minority of which were of school age. It should be noted that at
the time the 1986 study was conducted, there were relatively limited amounts of
real-world data on the effectiveness of lap belts in the rear seats of passenger
cars. Based on the differences in the body sizes of school bus and passenger car
occupants, and the importance of proper position and adjustment of lap belts,
it is not clear that the "up to 20 percent" effectiveness estimate was
accurate with respect to school buses. Since
the mid 1980's, additional and significant real-world data have been obtained
on the effectiveness of lap belts for rear seat occupants in passenger cars, primarily
since belt usage in motor vehicles has increased dramatically in that time frame.
Based on real-world crash data through 1996, NHTSA currently estimates that lap
belts in school buses at best would be 5 percent effective in reducing school
bus passenger fatalities. ________
It should be noted that while improvements have been made in school bus loading
zone safety since the National Academy of Sciences' 1989 report, the greatest
safety risk to pupils riding school buses is still as a pedestrian in the school
bus loading zone. When all pupil transportation modes are considered, the greatest
safety risk to students is as a pedestrian walking to or from school or as a passenger
in a private motor vehicle transporting the student to or from school. Page
11 Considering
those crashes where lap belts would likely exacerbate injuries, NHTSA estimates
that lap belts would have no overall effectiveness in school buses. In its conclusions,
NHTSA noted that the greatest benefit of lap belts to rear seat occupants of passenger
cars was in terms of preventing ejection from the car, typically in rollover crashes.
Since fatalities and serious injuries due to ejection from a school bus are relatively
rare events, the effectiveness rate of lap belts in passenger cars is not directly
applicable to school buses. These NHTSA conclusions were provided at an August
1998 Public Hearing held by the National Transportation Safety Board on Bus Crashworthiness
and Occupant Survivability. Lap
Belt Concerns In
addition to the NHTSA comments at the August 1998 Public Hearing, an international
panel of experts in the field of motor vehicle occupant crash protection testified
about their views and opinions on how best to provide passenger crash protection
to children in school buses. Five researchers, representing Australia, Canada,
Europe, and the United States were asked about the appropriateness of lap belts
in providing crash protection to small children. The unanimous opinion was that
lap belts were not a good means of providing crash protection to small children
because small childrens' bone structure, particularly their hips, is still developing
through grade school. One
of the researchers discussed a passenger car crash where "...two children
have become paraplegics in the rear of one vehicle that was struck head-on, because
they were wearing lap belts, and they suffered severe injuries to their spine."
Another researcher commented that, "The lap belts involve, in my mind, an
unsatisfactory compromise." A third stated. "...as regard children,
I would never ever recommend using lap belts." A comment by one of the researchers
appears to accurately reflect the views of all of the international researchers
- "So I think there is a lot to be considered before we wave our arms and
say, 'Lap belts are the answer'." In
addition to the potential for a lap belt to cause internal injuries to small children,
lap-belted school bus passengers also risk more severe head and neck injuries
in crashes. Unlike passenger cars where there may be a significant amount of space
between the rear seat and the front seat, in school buses the seat spacing has
been significantly reduced by design. In 1985, Transport Canada issued a report
on a series of crash tests it conducted to examine the outcome of lap-belted test
dummies in simulated frontal crashes. These tests indicated that lap-belted test
dummies in school buses received more severe head and neck injuries than unbelted
test dummies in severe frontal crashes. At the time, several individuals questioned
the test procedures and results of the Transport Canada study. However, no additional
testing was done. In a 1997 series of crash (sled) tests conducted by NHTSA, the
same results were found - lap-belted test dummies in school bus seats received
higher head injury measures than unbelted test dummies. These 1997 tests appear
to confirm the earlier study by Transport Canada. In
a November 2, 1998, speech before the annual conference of the National Association
for Pupil Transportation, Jim Hall, Chairman of the National Transportation Safety
Board spoke about school bus passenger crash protection. In his comments, Chairman
Hall stated that, "I personally think its our turn now to step up to the
plate on the issue of lap/shoulder belts in school buses." [Emphasis added.]
Chairman Hall also stated that, "It is time for the school pupil transportation
network of this country to call on the manufacturers and regulators to make this
happen, rather than waiting for it to happen."
Page 12 While
these comments may be interpreted that Chairman Hall personally believes lap/shoulder
belts should be installed in school buses right away, such a position is not supported
by other statements he made. Specifically, Chairman Hall stated that while "we
have to stop being indecisive on this issue," we should "commit to doing
it, but let's do it right." Chairman Hall reiterated that "we have to
make sure this is done on the basis of solid science. We don't want to simply
bolt in lap belts at every seating position." Finally, Chairman Hall stated
that "lap belts are probably not the most effective form of restraint for
the millions of children transported on school buses." While
lap/shoulder belts in school buses may be one of the most logical technologies
to evaluate, there is a significant amount of research to conduct before drawing
conclusions about the efficacy of lap/shoulder belts in school buses. For example,
the necessary science on how to design and install lap shoulder belt systems in
school buses, such that they would be effective in reducing injuries and fatalities
to all sizes of pupil passengers, has recently been initiated by several companies.
The importance of developing the necessary data and science to determine the proper
location of the shoulder belt anchorage point, so that it allows the shoulder
belt to be in the proper location across the chest of every size child, can not
be overlooked. There is considerable evidence that improper shoulder belt positioning
is a significant safety problem in other types of motor vehicles. If we rush to
install lap/shoulder belts in school buses without developing the necessary data
and science, we may very well establish policies that result in a negative effect
on the safety of children in school buses. Additional Comments on
Lap and Lap/Shoulder Belts At
the 1998 Annual Conference of the Association for the Advancement of Automotive
Medicine, several presentations were made concerning injuries to children in motor
vehicle crashes. In each case, it appears that the crashes investigated were confined
exclusively to passenger vehicles. No school buses were included. One
of the papers compared injuries to children restrained in lap belts and lap/shoulder
belts. The authors studied the injuries to 98 children 15 years old or younger,
half of which had been restrained in 2-point lap belts and the other half restrained
in 3-point lap/shoulder belts. Seventy two percent of the children in the study
were between the ages of 5 and 9 years -- the ages of children who typically ride
school buses. The paper noted that, "Injury risks to children restrained
in 2-point belts have been well described. 'Seat belt syndrome,' associated with
the use of 2-point belts, includes contusion of the abdominal wall, fracture of
the lumbar spine, and intra-abdominal injury." __________
"Injuries to Children Restrained in 2- and 3-Point Belts," Catherine
S. Gotschall, Allison I. Better, Dorothy Bulas, and Martin R. Eichelberger of
the Children's National Medical Center, and Frances Bents and Mike Warner of Dynamic
Sciences, Inc., October 1998. 42nd Annual Proceedings of the Association for the
Advancement of Automotive Medicine. This paper includes an extensive list of references
which undoubtedly provide excellent information on crash protection for children. Page
13 The study
concluded that, "Children restrained in 3-point belts exhibit a similar pattern
of injury to those in 2-point belts, however 3-point belts appear to be protective
for the lumbar spine." The authors of this study noted that while it included
data on more real-world crashes than previous studies of the effects of 3-point
lap/shoulder belts on children, it was still a relatively small study, and excluded
belted children who were uninjured in motor vehicle crashes. The absence
of data on children using lap or lap/shoulder belts who where uninjured makes
it impossible to draw any conclusions about the absolute or relative effectiveness
of lap or lap/shoulder belts on children. The authors did not believe it was possible
"to meaningfully compare the relative efficacy of the two restraint systems." The
purpose of citing this study is not to suggest that the paper or the authors of
the paper believe children are better off unrestrained in motor vehicles. Rather,
studies such as this appear to indicate that all types of passenger crash protection
devices may have unique consequences for children. The State Directors Association
believes it is extremely important to understand the interaction of all types
of passenger crash protection devices on the human body. Much is learned through
epidemiological studies that are conducted by the medical community. If children
or adults are needlessly being injured in real-world crashes, such studies can
assist in the identification of problems and the development of solutions to those
problems. While
this study and others appear to be based exclusively on children in passenger
cars and other private vehicles, the conclusions point out legitimate issues that
must be fully understood with respect to the appropriateness of lap belts or lap/shoulder
belts in school buses. Some have postulated that differences between school bus
seats and passenger car seats are significant and that these differences reduce
concerns about belt-induced injuries to small children. Others question whether
there is scientific evidence that demonstrates the effects of seat designs on
the relationship between lap and lap/shoulder belts and a child's skeletal development.
This is the type of information that is expected to be developed during NHTSA's
school bus passenger crash protection research program, which is discussed later
in this paper. Types of School Bus Crashes Nationwide,
the National Safety Council estimates that approximately 30,000 crashes occur
each year in which a school bus is involved. Less than 7,000 of these crashes
involve "injuries" to school bus occupants. Most of these injury-involved
crashes are minor in nature, however, serious school bus crashes do occur. When
a serious crash occurs, the school bus passengers are mostly uninjured or receive
minor to moderate injuries. These serious crashes involve frontal, angular, side,
rear, and rollover crashes. ___________ The
National Safety Council recently determined that the data it collects from individual
states are inconsistent and unreliable indicators of actual injuries to school
bus occupants. Accordingly, school bus occupant injury data will not be estimated
by the National Safety Council in the future. According to mid-1980's
state crash data reviewed by the National Academy of Sciences, only 5 percent
of school bus passenger injuries are incapacitating (e.g., severe lacerations,
broken limbs, head/chest injuries). A 1997 study of state crash data by NHTSA
showed only 4 percent of school bus passenger injuries were serious, severe, or
critical. Page
14 Unfortunately,
there are crashes that result in serious injuries or fatalities to school bus
passengers. Most of these crashes are very severe, and as reported by the National
Transportation Safety Board in its 1987 report: "schoolbus occupant
deaths and the serious or worse injuries ... were, for the most part, attributable
to the occupant's seating position being in direct line with the crash forces.
It is unlikely that the availability of any type of restraint [emphasis added]
would have improved their injury outcome." With respect to minor
and moderate injuries, as discussed earlier, the Safety Board's study found that
lap belt use would have worsened the injury levels for 20 percent of the students
receiving moderate injuries. It was not possible to judge the effect of lap belt
use on those passengers that only received minor injuries. Obviously,
there are some school bus crashes where lap belts may have reduced or eliminated
injuries and/or fatalities. As was done in the National Transportation Safety
Board's 1987 study, it is possible to assess what injuries may have been mitigated
because of lap belts. However, it is much more difficult to suggest what injuries
may have occurred as the result of the use of a lap belt, and whether those injuries
would have been more severe than the injuries that were mitigated. In
order to evaluate objectively the potential safety benefit of any device, all
aspects of the device must be studied and understood. It is not legitimate to
consider isolated or anecdotal information and ignore a larger body of information
and knowledge. Similarly, it is not legitimate to rely on hypothetical, theoretical,
and/or laboratory information when real-world information exists. Other
Organizations There
is unanimity among a wide range of national organizations that are charged with
establishing national motor vehicle and highway safety policy that "compartmentalization"
is effective in school buses and that lap belts should not be required in school
buses. However, as with any controversial issue, there are organizations that
believe there should be lap belts in school buses. These include a number of medical
associations and state-level organizations. These organizations express their
support for lap belts in school buses, but generally publish little or no data
or detailed analyses to explain and justify their position, or do not consider
all of the real-world data discussed above. In
the best interest of the safety and health of children, it would be beneficial
if organizations that take a position on safety matters dealing with pupil transportation
provided a detailed discussion and rationale for their position. This should include
all of the facts, statistics, and analyses upon which the position is based, and
should include a detailed discussion of why opposing views are incorrect or inappropriate. ___________
These organizations include the National Highway Traffic Safety Administration,
the National Transportation Safety Board, the National Safety Council, the National
Academy of Sciences and others. Page
15 Some organizations
and individuals have mis-characterized the conclusions from the 1989 National
Academy of Sciences' report discussed earlier. In that report, the Academy concluded
"seat (lap) belts, when properly used on post-1977, Type I school buses,
may reduce the likelihood of death or injury to passengers involved in school
bus crashes by up to 20 percent." [Emphasis added] According
to a March 27, 1998, Florida Senate Staff Analysis and Economic Impact Statement,
the Florida PTA utilized the National Academy of Sciences' report to assert "that
seat belts. on school buses would improve safety by 20 percent." [Emphasis
added] Similarly, a citizens' group in Minnesota, People Advocating Seatbelt Safety,
also claimed that "50% usage would reduce deaths and injuries by 20%."
[Emphasis added] There
is a significant difference between the National Academy of Sciences' conclusion
that says "may" and "by up to" and Florida PTA's and Minnesota's
claim of "would." This is particularly important since the data used
by the National Academy of Sciences were based on adults in the back seat of passenger
automobiles, not children in school buses, as discussed earlier. Also, the 1989
data used by the National Academy of Sciences are outdated. The most recent real-world
data indicate that at best lap belts would be 5 percent effective in reducing
fatalities, but most likely would have no overall effectiveness. Lap
Belt Requirements in New York and New Jersey Currently,
there are two states that require the installation of lap belts in large school
buses. New York has required the installation in all new school buses purchased
after June 30, 1987. However, New York does not have a law requiring students
to use the lap belts. Such requirements are left up to the individual school districts.
Recent information provided by New York indicates that only 26 (4 percent) of
New York's 709 public school districts have adopted policies which require all
students to wear the available lap belts. Those school districts report an estimated
88 percent of elementary, 71 percent of middle, and 47 percent of high school
students wear the available lap belts. New
Jersey passed a law in 1992 requiring the installation and use of lap belts in
all new large school buses. While there is no official data on lap belt usage,
New Jersey estimates that 75 percent of students wear the available lap belts,
and that elementary-aged children use them more than high school-aged children. The
National Transportation Safety Board attempted to conduct a study of the effectiveness
of lap belts in school buses in New York and New Jersey several years ago, however,
the study has not generated any useable information since (thankfully) there have
not been any serious crashes of school buses equipped with lap belts. As a result,
there is no body of real-world data involving all types of serious school bus
crashes that support the position that lap belts provide additional levels of
crash safety in the aggregate over the safety provided by "compartmentalization."
___________ The
term "seat belt" on school buses as used by the Florida PTA is interpreted
to mean lap belts, since that was the type of belt system considered by the National
Academy of Sciences in its study.
Page 16 Potential Changes to School Bus Passenger Crash Protection In
August 1998, NHTSA announced an extensive 2-year research program to consider
improvements to school bus passenger crash protection requirements. In announcing
the program, NHTSA reiterated its belief that "compartmentalization"
has proven to be an excellent form of child crash protection, but believes it
is important to develop the necessary data and science to develop the next generation
of passenger crash protection in school buses. The NHTSA research program is designed
to determine whether it is technologically feasible and operationally practicable
to upgrade the current Federal standards for passenger crash protection in school
buses. The research approach is direct - develop data on existing school bus crashes
to determine the causes of fatalities and serious injuries; use that data to evaluate
existing and alternative passenger crash protection systems in a laboratory test
environment; and consider the impact of various passenger crash protection systems
on school bus capacity and emergency egress. Based on the results of this research
program, the data and science necessary for making informed decisions about the
safety of all children in school buses will be available. The
State Directors Association fully supports the NHTSA research program, and notes
that it contains much of the content and logic suggested by the Association in
July 1998. The State Directors Association has requested that NHTSA expand the
scope of its research program to include all sizes of school buses, based on the
Association's concerns about the appropriateness of lap belts as a form of crash
protection for young children. The State Directors Association maintains its belief
that the two most logical options to consider in any research program on the subject
of passenger crash protection in school buses are: (1) lap/shoulder belts for
all designated seating positions; and (2) upgrades to "compartmentalization." Lap/Shoulder
Belts As stated
earlier, there is unanimity within the motor vehicle safety community that lap/shoulder
belts offer superior levels of occupant crash protection over lap belts only.
At the current time, there is little, if any, information available on the technological
feasibility, operational practicability, potential benefits, and other potential
positive and negative concerns associated with the installation of lap/shoulder
belts in school buses. The State Directors Association believes it is important
to develop as much information as possible on lap/shoulder belts in school
buses in the course of the NHTSA research program. This includes assessing engineering
issues associated with installing lap/shoulder belts in school buses, given the
Federal requirements for "compartmentalization," and whether some of
the Federal requirements would have to be eliminated or modified. It also includes
an understanding of the potential injury risks to small children from lap/shoulder
belts. As discussed earlier, the medical community regularly conducts epidemiological
studies of motor vehicle crashes involving children, and such studies may provide
important insight into the relative safety of various forms of passenger crash
protection in school buses.
Page 17 The
development of a better understanding of the types and causes of injuries occurring
to passengers in school buses can not be overstated. This information can only
be gathered from medical records, either from the hospital or physician that treated
the injured child. Without medical information on the type and severity of injury
being suffered by school bus passengers in various types of crashes, it is not
possible to properly evaluate the relative benefits of different forms of passenger
crash protection in terms of preventing or inflicting injuries to children in
school buses. Without data on how and when lap belts, or lap/shoulder belts, or
"compartmentalization" either reduce the risk of injury or cause an
increased risk of injury to children on school buses, it is inappropriate to suggest
changes to current requirements for the crash protection of school bus passengers.
Since it is unrealistic to expect all school bus passengers would wear the
lap/shoulder belts, and wear them correctly, it is important to identify potential
safety issues to the unrestrained school bus passengers, who may not have the
benefits of "compartmentalization" if lap/shoulder belts were installed
at all designated seating positions. The State Directors Association does not
believe the safety of those children, who either can not or do not want to utilize
an available lap/shoulder belt, should be compromised. Upgraded Compartmentalization Unlike
lap/shoulder belt systems which require school bus passengers to buckle up, "compartmentalization"
is a passive passenger protection system. It may be possible to make school buses
even safer through improvements in energy-absorbing materials and the use of energy
absorbing construction at seating locations. The
Summary and Conclusions section appears at the beginning of this paper.
COPY; 1999 National Association of State Directors of Pupil Transportation Services.
All rights reserved.
Issued: January 1999
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