OLR Research Report

April 7, 1998 98-R-0474

FROM: James J. Fazzalaro, Principal Analyst

RE: Seat Belts on School Buses

You asked us to respond to five questions and issues raised by someone to whom you had provided previous OLR reports on the subject of requiring seat belts on large school buses (OLR Reports 93-R-945 and 97-R-1167). The questions and issues were raised by a proponent of such a requirement.

The five questions and issues raised in the letter are as follows:

1. Compartmentalization (a) entirely assumes bus accidents will be either frontal or rear end collisions and ignores the possibility of side or rollover accidents and (b) will not help passengers in the aisle seating positions who may not be seated directly in front of the seat back ahead of them.

2. The studies we described in our previous reports are based on information that is more than 10 years old and, by implication, are too out of date to be valid. The reports discussed "old fashioned" lap belts and not the three-point lap and shoulder belts used in passenger cars.

3. Not requiring seat belts in buses does not "make sense" in light of the fact that children are told to wear restraints in passenger vehicles.

4. Seat belts on school buses would positively affect student behavior in that the children strapped into the seats would be limited as to what they could do to cause trouble on the bus.

5. Lawmakers should realize that school bus passengers face "imminent danger" every time they step on a bus and action should be taken before they become statistics.

We have provided additional information and analysis below for the first four points but are unable to respond to the fifth point in that it is more of a position statement and it is not appropriate for our office to debate such policy positions. We would also like to correct a statement in the letter asserting that OLR "concluded, based on the studies it quotes, that seat belts are not necessary on school buses." We believe this may mischaracterize the content of the two reports, in particular the detailed treatment of the issue in Report 93-R-945. At no point in these reports have we "concluded" that seat belts are necessary or unnecessary and it would be inappropriate for us to take such advocacy positions.

We noted in our reports that examinations of the issue by competent bodies, such as the Transportation Research Board (TRB) and the National Transportation Safety Board (NTSB) have noted that seat belts can provide benefits in some cases but not in others and that a national mandate is not warranted in light of several factors, including the fact that states can make their own decisions on requiring them (as New York and New Jersey have done). The Connecticut legislature has considered the seat belt issue on several occasions, including this year, and has thus far taken a similar policy position, i.e., that local school districts are not prevented from requiring belts in buses, but that a state mandate is not warranted. These are the conclusions of others, not OLR.


Compartmentalization was a safety concept adopted by the National Highway Traffic Safety Administration (NHTSA) in the late 1970s as the national standard for school transportation. It is based upon research conducted by NHTSA and others and is part of a series of construction and equipment standards that apply to school buses. The idea of compartmentalization is to create a forgiving interior inside of a strongly constructed exterior by means of high-backed, heavily padded, closely spaced seats, and few objects in the bus interior to present injury hazards. The other idea underlying the compartmentalization concept is that it is "passive" protection, that is, it does not require student passengers to do anything to derive its benefits. During a crash, riders are intended to be thrown into this cushioned compartment where crash forces can be absorbed and distributed by large areas of their bodies rather than at the head and neck. NHTSA also believes that compartmentalization is the most cost effective way of providing protection for the broadest range of children and makes evacuation of the bus following the accident easier.

As the continuing debate over seat belts on school buses would indicate, not everyone accepts the compartmentalization concept as the preferable alternative. While it is most effective in frontal crashes, which are the most common form of school bus collisions, it does not appear true that it provides no benefits in side impact or rollover accidents. NHTSA, NTSB, and others have examined school bus accidents in great detail, including serious rollover accidents, and concluded that compartmentalization generally provided riders with the intended level of protection. As we indicated in the reports we previously provided to you, NTSB also drew some general conclusions on the usefulness of seat belts in these accidents.


The Validity of Cited Reports

We know of no serious criticism that has ever been made, even by seat belt proponents, that the 1989 TRB study of school bus safety issues (Special Report Number 222--Improving School Bus Safety) or 1987 NTSB's examination of the crash performance of belt-equipped and non-belt-equipped large school buses (NTSB/SS-87/01--Crashworthiness of Large Poststandard Schoolbuses) are no longer relevant to the issue based on when they were conducted. These remain generally recognized as two of the most comprehensive and important studies ever conducted on these issues. Seat belt proponents have challenged the TRB report's conclusions, but have never to our knowledge attacked it as no longer relevant. The NTSB study described in our previous reports examined 43 serious school bus accidents, including side impacts and rollovers and it still appears to be the definitive study of what happens to belted and unbelted passengers in large school bus accidents. The NTSB announced in 1995 that it would begin once again to analyze crashes involving large school buses in response to New Jersey's adoption of a seat belt mandate, but most observers believe that, because school bus accidents, particularly serious ones, are so infrequent, it will be several years before there is enough data for a follow up report on the performance of seat-belt equipped buses. In any case, the TRB and NTSB reports still appear to be the two most important sources of objective and comprehensive information on this subject produced to date.

We would also note that seat belt proponents frequently refer to the results of several crash and sled test studies as evidence of the benefit of seat belts for school bus passengers that are considerably older that the TRB and NTSB analyses. These include crash tests conducted at UCLA in 1967 and 1972, sled tests conducted by NHTSA in 1976, and crash tests conducted by Transport Canada in 1984.

Why Only Lap Belts

With respect to the question of why discussions about seat belts in school buses still involve only consideration of lap belts and not lap and shoulder belt combinations available in passenger cars, the answer is that there currently appears to be no practical design for lap/shoulder belt systems that can be used in large school buses without abandoning the compartmentalization concept entirely. For a lap and shoulder belt unit to be effective, current seat backs, which are intentionally designed to be flexible as part of the compartmentalization concept, would have to be stiffened in order for the belts to work properly. This essentially means that a bus could not have both compartmentalization and three-point restraints. NHTSA strongly believes that compartmentalization is the most effective form of protection for school bus occupants because it is "passive" protection. It provides the anticipated safety benefits without any specific actions by occupants. NHTSA opposes weakening the compartmentalization concept in this way because while belted occupants might benefit from three-point restraints, children who did not wear their belts would be afforded less protection from the seat backs than they have now.

Some bus manufacturers, such as Blue Bird Bus Company, have identified three-point restraints integrated into the seat padding as a possible feature of their 21st Century "concept" buses, but when such vehicles will reach the point of practical availability remains to be seen.


Proponents of seat belts in school buses frequently raise the point that children get confused about having to wear seat belts in passenger cars but then not school buses. If they were required to wear them in both types of vehicles, there would be a “carryover” effect in educating them to use belts at all times. There is some logic to this position on the surface and a few members of the panel conducting the TRB study believed this should be a reason for requiring belts in large buses, but most of the panel did not agree. While valid in the broader sense, the idea underestimates the importance of two things that distinguish school buses from passenger cars and have guided policy makers on the seat belt issue: (1) that school buses are larger, heavier, and differently constructed than passenger cars and have intentionally padded, more forgiving interiors without door handles, steering wheels, dashboards and other objects that frequently cause the types of injuries seat belts are intended to avoid or minimize and (2) that the primary purpose of seat belts in passenger cars is to prevent ejection through the adjacent door, a hatchback, or the windshield, which is the most potentially fatal event that occurs in a crash. Several studies have examined the additional risk faced by an ejected vehicle occupant and have concluded that someone may be 12 to 40 times more likely to be killed if ejected from a vehicle during a crash than if the he remains in the vehicle.

The design features of school buses make ejection from the vehicle an extremely rare occurrence, usually happening only when the accident is so catastrophic, such as a collision with a large truck or a train, that the bus body is ripped open. In such extremely violent accidents, the entire seat is likely to be ejected from the bus, so belts might not provide any advantage. The greatly reduced likelihood of ejection tends to reduce the main function of seat belts.

These notions are difficult for most people to internalize, even if they accept their validity, and it may require considerable effort to educate children to the differences between their school bus and their family car. There is also conflicting evidence as to whether there really may be a cross-educational benefit. While surveys of some school districts with belt-equipped buses have produced opinions that there is such a benefit, a NHTSA study of the question failed to find a correlation between students who ride in seat belt equipped school buses and higher seat belt use rates in passenger vehicles. The study concluded that parents' influence was more likely to result in general seat belt use than the existence of seat belt equipped school buses.


The idea that students will behave better if they are riding in seat belts in the school bus also makes a certain amount of common sense that is supported by some opinion surveys done in school districts that have belt-equipped buses. But a 1994 study done by the Center for Urban Research at the University of South Florida raises a question as to how great an influence it may really be. The study collected information on the operational experiences of 814 school districts operating belt equipped school buses. The researchers found that more than three-quarters of the responding districts indicated that their students are using the seat belts no more than 10% of the time they are on the buses and only 6% of the districts said that students use belts more than half the time. The researchers also found that more than 90% of the responses showed no overall improvement in student behavior because there were seatbelts in the buses; 9.6% said that behavior had improved; and one district reported an improvement only in its elementary school riders.

Districts that are concerned with improving on-board student behavior seem to have other more effective methods to accomplish this. Some school districts use bus monitors and many have begun to use video surveillance cameras mounted in the buses. While it may be appropriate for students that exhibit repeated disruptive behavior on buses to be denied riding privileges, it must be understood that transportation experts generally believe that there is no safer means for them to get to and from school, including in the family car. The National Safety Council estimates that school buses are four times safer than passenger vehicles per vehicle mile and 28 times safer per passenger mile.