Motor vehicle manufacturers have developed and deployed rollover roof rail mounted air bags to mitigate occupant injury and the potential for occupant ejection in rollover collisions. Some manufacturers have published information on the type of rollover collisions that are used to establish criteria and define the circumstances for rollover air bag deployment commands.

This paper examines the National Automotive Sampling System Crashworthiness Data System (NASS CDS) to characterize the type and severity of roll over collisions that occur on United States roadways and reports upon the distribution of rollover occurrence by type, and rollover injury occurrence by type of rollover event. Involvement rates are reported for light duty vehicles. Occurrence rates for roll over collision and roll over collision related injury are compared to the rollover collision types that have been identified by motor vehicle manufacturers to assess the proportion of roll over collisions and injuries that might be subject to mitigation with the installation of roof rail mounted rollover air bags.

This comparison shows, if all light duty vehicles in the new vehicle fleet applied similar deployment criteria, approximately 84% of rollover collisions and injuries could be subject to the injury mitigation effects of existing roof rail mounted roll over air bags.