Why aren't seat belts required to be used on school buses?

The United States Department of Transportation, National Highway Traffic Safety Administration is responsible for establishing motor vehicle safety manufacturing standards and requirements for vehicles, including school buses. The standards developed for the manufacture of school buses incorporate an occupant protection design referred to as “compartmentalization," which is unique to the school bus. This standard provides a protective envelope consisting of strong, closely spaced seats that have energy-absorbing seat backs. The effectiveness of compartmentalization has been confirmed in the National Transportation Safety Board and National Academy of Sciences studies. School safety standards have been adopted into the Michigan Vehicle Code which exempts large buses, over 10,000 pounds, from the seat belt requirements. Small school buses that weigh less than 10,000 pounds must be equipped with lap or lap/shoulder belts. Since smaller buses are closer in size and weight to those of passenger cars, the agency believes seat belts in smaller buses are necessary to provide occupant protection. Drivers of all sizes of buses are required to wear seat belts because the drivers are located in the front of the bus with no seat ahead of them, so they are not protected by a compartmentalized space.