May 8, 2002
NHTSA concludes lap belts not beneficial in big school buses
Washington, D.C. – The U.S. Department of Transportation’s National Highway Traffic Safety Administration (NHTSA) released a new report assessing occupant protection in school buses.
The report shows that in comparison with other forms of transportation, students are nearly eight times safer riding in a school bus than in cars. The fatality rate for school buses is 0.2 fatalities per 100 million vehicle miles travelled (VMT) compared to 1.5 fatalities per 100 million VMT for cars.
This safety record is a result of the U.S. Department of Transportation’s requirements for compartmentalization on large school buses, and lap belts plus compartmentalization on small school buses. Compartmentalization is the name for the protective envelope created by strong, closely-spaced seats that have energy-absorbing high seat backs that protect occupants in the event of a crash.
The new NHTSA report concluded that requiring lap belts on large, new school buses would appear to have little, if any, benefit in reducing serious-to-fatal injuries in severe frontal crashes. In fact, tests indicate that in some severe frontal crashes there may be increased risk of serious neck injuries and possibly abdominal injury among young passengers wearing lap belts.
However, in small school buses, any increased risks associated with the use of lap belts are more than offset by preventing ejections. These buses weigh less, have different crash dynamics, and are more prone to rollover than large school buses.
The use of combination lap/shoulder belts, if used properly, could provide some benefit on both large and small school buses. Lap/shoulder belts can be misused if children put the shoulder portion behind them. NHTSA’s testing showed that serious neck injury and perhaps abdominal injury could result when lap/shoulder belts are misused. Assuming 100 percent usage and no misuse, lap/shoulder belts could save one life a year.
Lap/shoulder belts also could reduce school bus capacity by up to 17 percent because of seat redesign, and add between $40 and $50 per seating position to the cost of a new vehicle. The most popular buses carry between 60 and 71 passengers. The total annual cost would be over $100 million.
Other considerations, such as increased capital costs, reduced seating capacities, and other unintended consequences associated with lap/shoulder belts could result in more children seeking alternative means of travelling to and from school. Given that school buses are the safest way to and from school, even the smallest reduction in the number of bus riders could result in more children being killed or injured when using alternative forms of transportation. In this context, NHTSA recommended that, if states and local school districts decide to require lap/shoulder belts on school buses, they should ensure that no passengers are forced to find alternate means of transportation.
Some states and local school districts have voluntarily installed lap belts in their large school buses. NHTSA continues to recommend that, if states or local school districts require seat belts on school buses, they should ensure that passengers wear them correctly. States and local school districts considering purchasing seat belts for large school buses should be aware of the results of this new NHTSA research report.
Over the past 11 years, school buses annually have averaged about 26,000 crashes resulting in 10 deaths – 25 percent were drivers; 75 percent were passengers. Frontal crashes account for about two passenger deaths each year.
Meanwhile, NHTSA is continuing its research program, focusing on side impact protection, working with university-based researchers to further study school bus crashworthiness.
The four-year research effort by NHTSA has pinpointed other improvements that could be made to improve the safety of school buses. The agency is considering the following changes to existing federal safety regulations:
- Increase seat back height from 20 inches to 24 inches to reduce the potential for passenger override in the event of a crash.
- Require buses under 10,000 pounds to have lap/shoulder restraints. Currently, passenger seats on these buses must be equipped with lap belts only. The agency also will consider seat redesign so the lap/shoulder belts fit correctly for all passengers aged six through adult.
- Develop standardized test procedures for voluntarily installed lap/shoulder belts.
A copy of the full report can be viewed on the agency web site: