Currently, one of the major challenges for automotive engineers is to provide additional protection to motor vehicle occupants involved in side-impact collisions. A considerable amount of research is being conducted into this problem by governments and motor vehicle manufacturers on a worldwide basis. Changes to the current safety standards relating to side impact protection have been proposed in both North America and Europe. The proposed standards involve the use of dummies in collisions between a moving barrier and a stationary test vehicle.A total of 22 side impact tests of production vehicles have been completed to date to assess the appropriateness of the test procedures developed in the U.S. and Europe in the context of the Canadian vehicle mix and associated side impact accident problem.Vehicle performance rankings provided by the two test procedures were found to vary greatly. These discrepancies can be attributed largely to the different loading induced by the two different moving deforming barriers. Examination of Canadian field accident data indicates that both barrier designs create loading environments which, in terms of maximum crush to the impacted vehicle, have a high likelihood of producing serious or fatal injury to a driver. Vehicle deformation patterns produced by the U.S. barrier, in the immediate proximity of the drivers seat, showed closer agreement with vehicle-to-vehicle damage patterns than did those produced by the European barrier.Delaying direct loading of the thorax until the pelvis has begun to accelerate was found to have a very favourable effect on the thoracic response.