Prediction of Accident Evolution by Diversification of Influence Factors in Computer Simulation: Opportunities for Driver Warnings in Intersection Accidents

Paper i proceeding, 2016

Single Accident Reconstructions and Traffic Simulation have both been frequently utilizedfor prospective assessment of advanced driver assistance and active safety systems. Whereas Single Accident Reconstructions cannot estimate False Positive rates due to the limitation to accidents and hence to True Positives and True Negatives, Traffic Simulation is prone to neglecting rare surprise events that are important for system performance. Further, a False Positive intervention does not necessarily imply driver non-acceptance. Driver comfort boundaries seem to be a more eligible metric for intervention acceptance. Intersection accidents are frequent and harmful. In the US, about 50% of all crashes with injuries are located in intersections or are intersection related. Approximately one third of all fatal crashes occur at these locations. About 24% of the road traffic fatalities in Europe are attributed to junction accidents. For Germany, straight crossing path accidents (SCP) and left turn across path accidents with traffic in opposite direction (LTAP/OD) are the most frequent intersection conflict types, covering one quarter of all car-to-car accidents. The objective of this study was the application of Single Accident Reconstruction data to virtual simulation to quantify the time available between comfort zone boundaries and physical limits for collision avoidance in the intersection scenarios SCP and LTAP/OD. Thus, the question is answered, if warning is an appropriate measure for intersection accident avoidance. We investigated different warning levels comprising the ego and target vehicle drivers’ alternatives to avoid impending collisions by either braking or steering within comfort margins and a range of warning thresholds at 3m/s^2 , 5m/s^2 , and7m/s^2 longitudinal and lateral acceleration. The results show that the available time is limited with 0.6 to 0.7 seconds (SCP) and 0.2 to 0.6 seconds (LTAP/OD) for the lowest warning level and a threshold of 3m/s 2 longitudinal and lateral acceleration. For higher warning levels and thresholds, available times decreased substantially. Negative times occurred in LTAP/OD scenarios when braking was considered on its own as a warning intervention decision, indicating that for some accidents comfort braking can be initiated later than braking at the physical limit.