What about seat belts? Why don’t school buses have them?
The short answer is that small school buses do in fact require seat belts; large school buses, with a few exceptions do not. Seat belts are not required on the larger school buses because both the U.S. Department of Transportation and Transport Canada, have determined that compartmentalization is the preferred occupant protection system.
To explain these differences in a greater detail we begin as follows; a small bus is categorized as a bus under 10,000lbs in weight, which are required by federal law to have seat belt systems on them due to the fact that they are closer in nature to the size of the average automobile and/or ...view middle of the document...
Protection from ejection is a primary function of automobile seats.
This primary function is the same rationale that school buses incorporate a passive restraint system known as compartmentalization, which is designed to protect the children without the aid of a seat belt.
A term that was coined in the late 1960’s by researchers from UCLA. It basically was termed compartmentalization, denoting a safety envelope or “compartment” around the passengers in school buses. The fundamental idea was that if a crash were to occur, that the child may be thrown around within this compartment but the design of the seat compartment would essentially absorb the crash force and protect the child.
After extensive research during the 1970’s the Department of Transportation and its agency, the NHTSA determined that the safest and most practical arrangement for school bus seating would be this “compartmentalization” concept. Accordingly, the new safety regulations that were effective for school buses manufactured on or after April 1, 1977, included this requirement among other improvements made that year.
Student riders are surrounded by a compartment of energy absorbing material – 4inch thick foam seats, seat frames that bend to absorb crash forces, and a vehicle designed to absorb energy. The idea is the crash force will be dissipated or absorbed before they get to the student passengers. However, compartmentalization doesn’t work well in rollover crashes, hence one of the reasons on the NHTSA’s regulatory update on seat belts
With these changes at that time seat backs were now higher in school buses, wider and thicker that before. All metal surfaces are covered with foam padding. This structure must then meet rigid test requirements for bending and absorbing energy, such as would be required if a student’s body were thrown against the padded back. In addition, the equivalent of a seat back, called a “ barrier”, is placed in the front row of seats at the front of the bus.
In addition to padding, today’s seats also must have a steel inner structure that springs and bends forward to help absorb energy when a child is thrown against it. The steel frame must “give” just enough to absorb the child in the seat ahead. Also, of course, the seat is required to be anchored to the floor so strongly that it will not pull loose during this bending action. And the floor itself must be strong that it will not be torn by the pulling action of the seat anchors during a crash.
Seats are spaced close together as another safety precaution to ensure containment of children after a potential crash. If seats are spaced too far apart, the student could be thrown too far before being cushioned and/or could be thrown outside the compartment altogether.
The federal government concluded that compartmentalization is a better safety measure than seat belts and arguments to favor this are as follows: