Background: Frontal crashes are the most common motor vehicle crashes (MVC), however, near sided crashes produce more severe injuries. Side impact airbags (SIAB) were designed to mitigate and prevent severe injuries and are associated with up to 45% mortality reduction as reported (IIHS 2003).
Objective: Limited data on deployment rates of SIAB in severe real world lateral crashes has been reported. The objective of this study is to determine deployment rates of SIAB in severe injury side impact collisions utilizing the Crash Injury Research and Engineering Network (CIREN) database.
Methods: The US Department of Transportation's National Highway Traffic Safety Administration CIREN database was queried for side impact MVCs during 1997 - 2009. There were 3,766 passenger vehicle crashes of which 515 vehicles had SIAB installed. Additionally, crash metrics, direction of force, delta V and SIAB sensor location were examined.
Results: Of the 207 cases involved in severe injury side impact crashes, there was a 63% deployment rate of SIABs in near and far side impact crashes. In sub analysis of SIAB deployment and occupant location there were 140 near sided crashes. In near sided severe injury crashes the SIAB deployment rate was 80%. In this study eight cases had no SIAB deployment with delta V above the assumed deployment threshold. Two of the eight cases were eliminated for having impacts outside of the region where the sensors are located leaving six cases, or 5% of cases with lateral delta V above 16 kph and no SIAB deployment for the near side occupant with severe injuries.
Summary: Real world CIREN data shows that 5% of SIAB did not deploy in severe injury side impact collisions with a lateral delta V above 16 km/h despite currently held perceptions from reports in the news media [
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,
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] that non deployment is more frequent in real world crashes. While the CIREN data used for this study uses real world crashes - the inclusion criteria for CIREN cases requires specific level of injuries to the case occupant in order to be included, thus the CIREN cases represent a subset of ALL real world crashes that have significantly injured case occupants. Further research on SIAB deployments and sensor location on a larger scale is needed in real world lateral impact crashes.