Field relevance of a suite of rollover tests to real-world crashes and injuries.

The objective of this study was to assess the distribution of rollover accidents occurring in the field and to compare the vehicle kinematics in the predominant field crash modes with available laboratory tests. For this purpose, US accident data were analyzed to identify types and circumstances for vehicle rollovers. Rollovers were most commonly induced when the lateral motion of the vehicle was suddenly slowed or stopped. This type of rollover mechanism is referred to as "trip-over". Trip-overs accounted for 57% of passenger car and 51% of light truck vehicle (LTV) rollovers. More than 90% of trip-overs were initiated by ground contact. Fall-overs were the second most common rollover type, accounting for 13% of passenger car and 15% of LTV rollovers. Bounce-overs only accounted for 8% of both passenger car and LTV rollovers. The FMVSS 208 dolly and the ADAC corkscrew rollover tests are well-known laboratory tests, but do not simulate many of the real-world rollovers. Three additional tests have been devised to more fully address the field relevant conditions identified in this study. To do so, assumptions were made and adding the new laboratory tests (soil-trip, curb-trip and ditch fall-over) increases representativeness to 83% of passenger car and 75% of LTV rollovers reported in the field. Accident data were also used to identify injuries in belted drivers so the information could later be used to better understand occupant kinematics in various roll conditions. The injury distribution for belted/non-ejected drivers was assessed for trip-over, fall-over and bounce-over accidents. Serious injuries (AIS 3+) were most common to the head and thorax, in particular for bounce-overs. Head injuries occurred from contact with the roof, pillar and the interior, while thoracic injuries resulted from contact with the interior and steering wheel assembly. Field data are useful in the development of laboratory test conditions for rollovers as it provides insights on the significance of various rollover types, understanding of injury biomechanics, guidance for future testing and inputs for mathematical modeling.