Data from multidisciplinary accident investigations in computer storage at HSRI were reviewed. Frontal crashes (11 1 o'clock impact direction) were studied comparing the injury severities of drivers and front right passengers with the injuries of rear-seat occupants. Occupant age, impact speed of vehicle, occupant seating position and use of restraint systems are some of the parameters that were studied. The potential of the rear-seat occupants to cause injury to front-seat occupants was also considered.

Data analysis reveals that rear-seat occupants are less likely to experience severe-to-critical injury and fatality than front-seat outboard occupants, and that rear-seat passengers are most likely to escape a crash without injury. Children in the rear seat are less likely to be injured than rear-seat adults. Rear-seat car occupants are less likely to be injured at all impact speeds. The most important factor found was the use of safety belts. Belt usage by front-seat occupants was almost sufficient to eliminate the advantage of being a rear-seat occupant.