Estimating bicyclist into pedestrian collision speed

Reconstruction equations used to predict vehicle impact speed from throw and slide distances of a pedestrian struck by a car, truck or bus cannot be applied to bicycle-pedestrian impacts. A series of MADYMO computer simulations of head-on and angled cyclist-pedestrian impacts were carried out and compared to the wide range of equations currently available for reconstructing vehicle-pedestrian impacts. For a given throw distance, the bicycle impact speeds were much higher for the simulated cyclist-pedestrian impacts than obtained from the calculated impact speeds involving a car, heavier truck of bus. Empirical equations for crash reconstruction analyses to determine impact speed of a cyclist striking a pedestrian based on measured throw and slide distance are presented. The simulation results also confirm Graw and Konig's observations that the dominant injury mechanism resulting from such impacts is usually associated with a secondary post impact pedestrian head strike with the pavement.