Abstract
Keywords: effectiveness of primary safety measure, collision avoidance, brake assist, advanced cruise control, rear-end crash, active safety, safety benefit, real world accident data
Primary safety systems are designed to help to avoid accidents or, if that is not possible, to stabilize respectively reduce the dynamics of the vehicle to such an extent that the secondary safety measures are able to act best possible. The effectiveness is a measure for the efficiency, with which a safety system succeeds in achieving this target within its range of operation in interaction with driver and vehicle. Based on Daimler´s philosophy of the "Real Life Safety" the reflection of the real world accidents in the systems range of operation is both starting point as well as benchmark for its optimization.
A prospective method of efficiency prediction for primary safety systems which yields statistically significant results is discussed for rear-end crashes. The method starts from a characterization of the conflict and the crash situation depicting its relevance in real word accident statistics. The optimization process is aimed at achieving best system performance under the spectrum of real world accidents. The method was applied to the conventional Brake Assist of Mercedes-Benz. The result matches excellently with former retrospective evaluations of German accident statistics. The appliance to the linkage of DISTRONIC PLUS with Brake Assist PLUS generated promising results. Despite very conservative restrictions the results confirm with the profound safety effects: DISTRONIC PLUS and Brake Assist PLUS can avoid more than 20% of all rear-end collisions. In an additional portion of 25% of collisions the linked systems contribute to a significant reduction of accident severity.