Dynamic Modeling of Management Policies for Emergency Evacuation

Evacuation is the transfer of population from one area to another in a limited time during disasters. The main goal of this process is to transfer people out of the risky area as quickly as possible to reduce casualties. Therefore applying management policies to reduce the duration of evacuation can play a vital role in minimizing the negative effects of crises. This paper aims to investigate the impact of some management policies such as contraflowing, determining the optimal evacuation routes and evacuation phasing in Sioux Falls network and the network performance after applying the proposed policies. Among the contributions of this paper can be mentioned that the previous models are often based on static traffic assignment, conventional mathematical models and heuristic methods in which traffic conditions are considered constant during the simulation period. However, due to the dynamic and unstable nature of the emergency evacuation process, dynamic traffic assignment and traffic simulation tools can be considered as a valuable alternative to develop suitable and dynamic emergency evacuation planning to facilitate the decision-making process to determine optimal measures. Therefore, the emergency evacuation process for a case study of the Sioux Falls network is simulated in Visum as a computer simulation software and the objective function is to minimize the time required for emergency evacuation. After simulating different scenarios, the research findings indicate that the volume of demand and phasing of evacuation are among the factors affecting the duration of emergency evacuation. Also, a reduction of network evacuation time by 10 to 30% was observed after the implementation of the proposed policies with different demand volumes and emergency evacuation phasing. Finally, it can be seen that changes in the amount of evacuation demand lead to more changes in the amount of reduction in evacuation time than the type of demand distribution function.