This paper investigates the issue of geometric incompatibility between vehicles involved in T-bone side impact crashes. Some illustrative examples and case histories are presented that clearly demonstrate how a bullet vehicle, with a high front bumper region and a raised bonnet with a very stiff facia, intrudes significantly into the soft section of a sedan shaped car resulting in sever head and chest trauma.

Experimental results of two T-bone crash tests:​ a sedan car into a sedan car and a Four Wheel Drive (4WD) vehicle into a sedan car are described. The paper also presents a MADYMO simulation of a tram impacting the side of a car demonstrating how head strike of the struck vehicle’s near side occupant can result in severe head injury at speeds as low as 35 km/h. The authors conclude with some discussion of how the front of vehicles should be designed so as to eliminate the possibility of sever intrusion and head strike in such crashes.