Simulation analysis for evacuation under congested traffic scenarios: a case study

In this paper a new simulation modeling approach to support evacuation traffic management is introduced and a case study is presented. Traditional traffic simulation models neglect some real-life factors that need to be considered in an evacuation, such as the effect of road information and active control measures to manage traffic flow while vehicles are competing to find the best or preferred route. A passive equilibrium-seeking modeling approach may not be suitable for evacuation trip analysis due to limited route capacity and likely severe congestion during an evacuation. This paper introduces a new updated cell transmission model using discrete-event simulation, which can review and analyze the preferred path of evacuation traffic from multiple starting locations (or originations) to multiple destinations. Using this approach, case studies are conducted based on the user equilibrium principle, since it represents a natural behavior in an evacuation process. This research also demonstrates that, with the help of the cell transmission simulation model, an active traffic control mechanism can be evaluated. This study found that active traffic control measures are capable of decreasing total travel time during an evacuation by thousands of vehicle hours. Incorporating behavior consideration into the evacuation planning can help form a more accurate and realistic analysis of an evacuation plan.