Effectiveness assessment of a generic collision mitigation system for motorcycles at junctions

Remarkable improvements have been made for passenger car occupants in recent years. The decrease in passenger car occupants is higher compared to motorcyclists. The risk of being killed as a rider or pillion rider on a motorcycle in a traffic accident is 3.5 times higher than in a passenger car. A relatively high number of casualties occur at junctions (approximately 21%) in the EU. In Austria 37% of motorcycle accidents are at junctions.
Active safety systems are considered to be a measure capable of reducing accidents not only for passenger cars but also for motorcycles, or at least being potentially able to mitigate the consequences of an impact. The objective of the study is to analyze the effectiveness of a generic collision mitigation system at junctions using a virtual forward simulation method based on real accident simulations. The motorcycle is virtually equipped with a collision mitigation system and the real accident is simulated again. The original reconstructed accident is compared to the simulation and the collision speed is analyzed. Four different intervention strategies are distinguished. The first strategy refers to a collision warning system. The second strategy is a semi-autonomous braking system and the third and fourth strategies are autonomous emergency braking systems.
All intervention strategies would reduce the collision velocity. Strategy a) has the highest potential (58.6%) to reduce the collision speed, followed by strategy d) with 48.3%. The potential of strategy b) is approximately 45% and c) close to 40%. The mean collision speed of the original accidents was found to be 59.5 km/h (SD=24.4). Using strategy a) the collision speed could be reduced to 40.5 km/h (SD=29.8) at average. The collision speed of strategy b) was at 48.8 km/h (SD=31.9), for strategy c) to 55.6% (SD=29.4) and for strategy d) the collision speed was at 49.8 km/h (SD=31.8).