This study compares three groups of real-world frontal crashes:​ those in which front-seat occupants were using no restraints, those in which they were wearing lap/shoulder belts, and those in which they were automatically restrained by air bags. The results show that both air bags and lap/shoulder belts (when worn) substantially reduce the likelihood of death and serious injury to front seat occupants of full-size and luxury cars involved in frontal crashes. The results also show that as the severity of the crashes increases, the role of the restraint becomes very important.

These comparisons of the injuries sustained by front seat occupants in real-world crashes tend to confirm the laboratory testing results, indicating that air bags can offer better protection in frontal crashes than lap/ shoulder belts when worn and substantially improved protection over no restraint. The results indicate that in frontal crashes, even compared to 100 percent lap/shoulder belt use, more lives could be saved and severe injuries reduced by the use of air bags.