Restraint effectiveness, occupant ejection from cars, and fatality reductions : potential fatality reductions through eliminating occupant ejection from cars.

Lap shoulder belt effectiveness and the fraction of fatalities prevented by ejection elimination are calculated according to direction of impact and rollover occurrence using FARS data. It is found that almost half of the effectiveness of lap/shoulder belts is due to ejection prevention. Total U.S. traffic fatalities would decline if all cars had restraint systems.