Optimization and simulation of traffic flows in the case of evacuating urban areas

In cases where urban areas need to be evacuated, a large number of vehicles must be routed through narrow street networks effectively. This paper combines two aspects of this problem. On the one hand, the traffic flows must be routed through the road network in such a way that e.g. the time required to get all out is as small as possible. Hence, we have to solve an optimization problem to find out which roads shall be used in what direction. On the other hand, even if routes are defined, traffic flows are dynamic in nature and phenomena related to the traffic jam are to be examined by simulation. By defining an optimization-based simulation procedure, we get a heuristic for the overall problem. As an example we compute and simulate an evacuation plan for a neighborhood in the city of Duisburg, Germany, to demonstrate the applicability of our approach to real-world sized problems.