This paper analyses the potential effectiveness of a restraint system for coach passengers and for all vehicle seats. The paper first clearly defines the type of restraint system required for effective coach passenger safety. Finally, the level of efficiency is estimated that can be achieved by such a restraint system based on a sample of 47 real world coach accidents occurred in France. The paper is based on the different types of main impact but above all on the various injury mechanisms. Results are provided after considering each passenger case involved in 47 coach crashes. For each passenger, the authors know precisely his or her location inside the vehicle before the crash, and the medical records of his or her injuries. The study shows to what extent it is necessary to improve safety for coach passengers and this can be achieved thanks to a specific restraint system. (A) For the covering abstract of the conference see IRRD 894848.