Using traffic microsimulation to evaluate potential crashes: some results Traffic microsimulation has been used extensively to evaluate consequences of different traffic planning and control policies in terms of travel time delays, queues, pollutant emissions and every other common measured performance while at the same time traffic safety has not been considered in common traffic microsimulation packages as a measure of performance for different traffic scenarios. The absence of safety evaluation with microscopic simulation models is due to a lack of complete and established models for the simulation of potential crashes. Commonlyused procedures for safety evaluation with microscopic simulation have been based on traffic conflict theory which until recently was not extended to single vehicle crashes and to crashes between vehicles which are moving on nonconflicting trajectories. This paper presents some applications of a new procedure based on potential crash events simulation for the evaluation of safety levels in microsimulated traffic scenarios which takes into account also potential crashes with road side objects and barriers.

Heterogeneity of Microscopic Congested Traffic Data Based on Drone Measurements We study vehicle trajectories at the onset and existence of traffic congestion and reveal its microscopic features on separate highway lanes. Drone observations of microscopic data of moving vehicles have been made available on threelane road segments of German highways. Based on these detailed empirical traffic data we reveal heterogeneity and complexity of congested traffic and discuss its consequences. E.g., to perform a safe and comfortable driving behavior by driver assistance systems or automated vehicles lanelevel traffic states should be adapted. A congested and dense traffic state only on the left lane of a threelane highway could be a serious danger. Moreover, we propose an empirical method to calculate local traffic densities that could be used to warn vehicles in advance about high preceding densities. We leverage that concept to study a local traffic jam and discuss its lanelevel properties. We reveal the heterogeneity of high local density structures on separate highway lanes.