They Are designed to prevent drivers and passengers from being completely ejected from a vehicle by spreading out their bodies’ energy over their shoulders, chest, and pelvis in a collision. This restraint must only be used on school bus seats. Entire seat directly behind must be unoccupied or have restrained http://ezproxy.cityu.edu.hk/login?url=https://www.ledteks.com/seatbelt-and-safety-belt-webbing