Austroads (2010b) defines run-off-road (ROR) crashes as occurring ‘when a vehicle leaves the road and often collides with a roadside object such as a tree or a pole’. Not all papers reviewed addressed ROR crashes explicitly. Rollovers, impacts with roadside hazards, loss of control, and single vehicle crashes all have strong correlations with ROR crashes. As such, these were assumed to imply ROR crashes unless the literature specifically addressed ROR crashes separately.