The Effect of Roll Velocity and Roof-to-Ground Impact Angle on Injuries in Lateral Rollovers

A previously developed two-dimensional model of a vehicle in a lateral roll (Rose, et al. 2008) was used in this study to analytically evaluate the effect of vehicle roll angle and roll velocity on roof-impact ΔV and consequent occupant injury mechanism and risk. Both occupants adjacent to (near-side) and remote from (far-side) the rollover’s leading side were evaluated. Injury evaluation was limited to head and neck/spinal injuries.

The vehicle’s roll angle at the time of roof-impact dramatically affected the local ΔV at the point of head-to-roof contact.

Both roof-rail impacts may be injurious to far-side occupants, while near-side occupants are more likely to sustain head or neck injuries in roof impacts with the adjacent roof rail. Far-side occupants have a greater risk of compressive neck injury during impacts with the remote roof rail, while adjacent roof rail impacts subject occupants to primarily lateral head impacts with a higher head injury risk. Contoured roofs may reduce the opportunity and risk of head or neck injury in rollovers.