Seat belts are not required on school buses and other large passenger buses because the NHTSA has determined that "compartmentalization" is better at providing protection during a collision. Although not federally mandated, some states require seat belts on buses and some school districts purchase buses with seat belts regardless. This may change soon, as the NTSB and other safety advocates are pushing for seat belts in buses.
The NHTSA contends that because of their size and weight, large school buses distribute forces differently than smaller passenger vehicles. For this reason, passengers experience much less force during a collision than if they were in a car or passenger truck.
The NHTSA, the National Highway Traffic Safety Administration, oversees federal regulation for seat belts on school buses.
Instead of seat belts, the NTSB requires that large school buses employ a technique called "compartmentalization." Compartmentalisation is why school buses have those tall, green seats. The energy-absorbing, high backs of the seats create compartments in between the seats to prevent children from injury during a collision.
Another explanation for the lack of seat belts on buses is the difficulty they might pose for evacuation during an accident. With the use of compartmentalisation, the NHTSA has determined that seat belts would not help in preventing serious injury.
Seat Belts Required
Seat belts are required on small school buses under 4536kg., and those that carry fewer than 15 passengers. These passenger vehicles are also required to have lap and shoulder belts. In addition, some states have seat belt requirements for buses and some school district purchase buses with seat belts, even when not required.
The National Transportation Safety Board, a separate agency from the NHTSA, strongly recommends a seat belt requirement in buses. They have listed it as one of their "Most Wanted Transportation Safety Improvements." The NTSB expects the new seat belt requirement will come about soon, to protect passengers during the event of a rollover.