Today's 39-inch wide standard seats may contain three small children or two large ones or any combination in between. Compartmentalization works whether students have fully developed abdominal areas or not. They need the help of chest harnesses also, which adds to the complexity of a proper safety belt solution. Compartmentalization, once it has done its energy absorbing job, leaves the student free to escape the bus. Seat belts could leave students strapped in, upside down, perhaps unconscious, in burning or flooding buses.
Compartmentalization is most affordable.
Although not a part of the DOT reasoning, this is a factor to be considered. In evaluating the cost of seat belts, one should include the cost of retractors and chest restraints, also, since those appear to be needed. Even more important to cost projections is the probability that a seat belt solution will lead to two students per seat and greater spacing between seats, thereby requiring more buses for the same student load. Return to Top Let's assume 2-point lap belts are required in school buses nationwide. Assuming the requirement applied only to new buses, and that retrofitting would not be required, about 25,000 to 30,000 large buses would be equipped annually.