Diving versus roof intrusion: a review of rollover injury causation

Rollover injuries are the outcome of the inability of a vehicle's crashworthiness design, or lack thereof, to protect its occupants during a rollover crash. While countermeasures for injuries due to ejection are well established, there is still much debate ongoing regarding injury mechanisms of occupants contained in a vehicle during a rollover and hence countermeasures required to mitigate such injuries. This paper presents and analyzes the two apparently conflicting views of injury causation for contained occupants in rollovers that have been presented in research literature to date: diving versus roof intrusion. To analyze the validity of each of these theories, the basic physics behind the underlying concepts is investigated. Injury results from the General Motors (GM) rollover Malibu II test series are then used and reanalyzed in light of the findings presented in this paper. Results show that the most injurious events in the Malibu II tests are those where the roof structure was not strengthened. It was also concluded that more work needs to be carried out to establish acceptable injury mechanisms and associated injury criteria for future rollover crash testing protocols.