Sport Utility Vehicle (SUV) Rollover Collisions: An Analysis of NASS - CDS Injury Data for 1998 through 2004

Rollover collisions are very complex and the subject of significant interest. Roll-over collisions involving Sport Utility Vehicles (SUV) are of particular interest due to their high center of gravity (increased propensity for rollover) and recent surge in popularity. The following research examines SUV rollover collisions documented in the National Automotive Sampling System (NASS) Crashworthiness Data System (CDS) for the years 1998 through 2004. The NASS/CDS was initially screened for SUV rollover collisions, then screened to eliminate soft top vehicles, such as the Jeep Wrangler and Suzuki Samurai. The injury data was further limited to driving age teens and adults (age 16 and older) in the front outboard seating positions. The data was evaluated with respect to injury severity using the Abbreviated Injury Scale (AIS), roof crush, seatbelt usage, seated position in the vehicle and with respect to roll direction (far-side/near-side), ejection status and crash severity measured by number of quarter turns of the vehicle. The data shows that ejection is the best single predictor of serious or fatal injury and that seatbelts are highly effective in preventing ejection. Further, seatbelted occupants have significantly less severe injuries than their non-seatbelted non-ejected counterparts, regardless of roll direction and number of rolls. As a general trend, non-ejected seatbelted occupants had a lower fraction of MAIS 3 and above injuries than their non-seatbelted non-ejected counterparts for various categories of roof crush depth; however, not all categories reached a p<0.05 level of significance.