One of the confounding factors in analyzing rollover crashes and in designing countermeasures for rollovers is the lack of a standard measure of crash severity. This paper examines NASS CDS 1997 to 2002 in order to determine rollover crash severity metrics and to recommend additional data elements to assist in determining rollover severity.
For belted occupants and unbelted ejected occupants in single vehicle crashes, the number of roof impacts is an appropriate severity indicator. Multiple vehicle rollover crashes carry higher injury risks than single vehicle crashes. The number of roof impacts and a (planar) delta-v are proposed as severity indicators for these crashes.