An evacuation network flow optimization model for city transportation systems with policemen resource allocation

Emergency evacuation has increasingly gained wide attention. In order to improve the evacuation efficiency, it is important to optimally allocate policemen to crucial roads in the city transportation systems. In this paper, we propose an evacuation network flow optimization model in which the policemen allocation decisions are integrated. It is assumed that the probability of traffic jams in one road is related with its flow and the allocated policemen resource. The problem is formulated as a nonlinear mixed integer program model which is proved to be NP-Hard, and a residual-network-based heuristic algorithm is developed to solve the model. We demonstrate the computational efficiency and effectiveness of the proposed model and algorithm by two practical transportation systems in Changsha, China.