Why don't school buses have seatbelts?

School buses provide students with the safest form of transportation to and from school, according to research by the National Academy of Sciences. School buses have to meet rigid federal construction standards for the sides and top of the bus, fuel tanks, and inside of each bus. The thick padded seats and seatbacks provide a passive form of crash protection known as “compartmentalization.” This padding, combined with the placement of the seating area high above the impact zone (with most other vehicles), offers a protection that has resulted in an unmatched record of passenger safety. Especially for small students, seatbelts can be more harmful than helpful, and in most states these are being phased out from school buses. Only since the early 2000s have lap-shoulder seatbelts been available on school buses in some states.