Real life accidents provide important information for understanding pedestrianhehicle collisions. Collision speed is the critical parameter in determining pedestrian injury severity and, where possible, this has traditionally been estimated from tyre skid marks. However, the introduction of ABS brakes has increased the importance of pedestrian projection distance as a means of estimating collision speed in real life accidents. This paper presents a theoretical Hybrid Model relating collision velocity to pedestrian projection distance. The model combines the flight trajectory of a simple particle with the distribution of post head-impact velocities predicted by Wood's Single Segment Model (SSM). Comparison with staged and real life accidents shows good predictions of minimum, maximum and mean projection distances. The overall distribution of collision speeds has been used to predict upper and lower limits and a mean value of collision velocity for a given pedestrian projection distance.