On an integrated approach to resilient transportation systems in emergency situations

In this paper we present an integrated approach to the evacuation problem under an emergency situation for transportation systems. The approach is based on a view that a service system has two subsystems: infrastructure and substance. The approach attempts to integrate infrastructure design and substance flow planning to improve the evacuation performance. Without loss of generality, we restrict infrastructure design to reconstruction of a damaged road with two attributes of the road: capacity and travel time, we restrict substance flow planning to the contraflow method, and we consider the evacuation problem with single source and single destination. Further, we apply the discrete variable Particle Swarm Optimization and RelaxIV to solve the problem model. The overall objective function in the problem model is a minimum transportation time. Since recovery of a damaged transportation (damaged road in this case) is implied in our problem, the proposed approach has some significant implication to resilience engineering of a service system as well. An example is studied to show the effectiveness of our approach; in particular it is shown that an integrated solution is significantly better than the solution with only the contraflow method.