Technical Parameters for Determination of Impact Speed for Motorcycle Accidents and the Importance of Relative Speed on Injury Severity

The value of on scene in-depth accident research studies has been recognized internationally and many countries worldwide have such teams. Since such detailed information is essential for improving the safety of cars, a strong collaboration with automakers developed. This resulted in Germany in a joint project between FAT (Forschungsvereinigung Automobiltechnik -Automotive Industry Research Association) and BASt (Bundesanstalt für Straßenwesen -Federal Road Research Institute). The project started on July 1999 and is called “GIDAS” (German In-Depth Investigation Accident Study). The paper is describing the methodology of this project with statistically orientated procedure of data sampling on the one hand and will give an overview of procedures for the determination of impact speed on the basis of an on scene investigation on the other hand. Crash information e.g. driving and collision speed have to be determined from tire marks and all artefacts at the scene as well as from the final position of vehicles. Different calculations are used by experts, momentum analysis and energy balance. Information on final position of vehicles, deformation pattern on vehicles, tire marks and artefacts found on the road like braking and sliding marks, throwing distances of the motorbike rider and the cyclists supplies possibilities for reconstruction of the movement of the human body and determination of collision speed. The paper describes the possibilities of the use of these parameters for reconstruction and will show the injury pattern for motorcyclists in the German traffic accident situation, based on the GIDAS sample in statistical representative manner.