A Time-Extended Network Approach to Planning Multi-Velocity Evacuation

To deal with the contradiction between the supply of infrastructures and the demand of multi-velocity traffic flow in a large scale evacuation, we present an algorithm based on time-extended network. It can be applied to making organized and staged evacuation plans. First, evacuees are grouped according to their locations and velocities. Then, individual starting time and route are allocated to each group in order to avoid any traffic conflict and ensure the efficiency of evacuation through recording time availability of each road segment. Following this plan, each group can move towards to the safe exit at their own velocity. Experiments demonstrate that, with this algorithm, the total evacuation time is close to the theoretical shortest evacuation time. And the larger the evacuation scale is, the better the algorithm performs.