Risk-based stochastic evacuation routing strategy under dynamic probabilistic route cost information

Abstract

Traffic information is rather helpful to travelers in the non-recurrent traffic incident such as emergency evacuation. Unfortunately, the most concerned information—intersection traffic signal—cannot be directly shown on the medium, for example, variable message sign, because of its large size and incomprehensible content. Thus, this article mines the signal data as well as queue length to generate a well-understood content named probabilistic route delay. In addition, this article combines both route delays and real-time travel time to obtain minimal dynamic route cost. These delays and costs are components of dynamic probabilistic route cost for information provision. Based on the conveyed dynamic probabilistic route cost information, a revised logit model is used to depict evacuees’ stochastic route-choice behavior, wherein a risk-based prospect value instead of the expected value is found to be a better choice in the non-random fixed utility. This risk-based stochastic evacuation routing strategy can generate more actual flow if it is compared to single prospect-value-based risky strategy or expected-value-based stochastic strategy. A case study on the evacuation of Nanjing Olympic Center is used to apply the risk-based stochastic evacuation routing strategy. A major contribution lies in that the proposed dynamic probabilistic route cost information and the risk-based stochastic evacuation routing strategy are effectively integrated. This integration can be used to determine variable message sign information or optimize signal timings, which would serve for the most efficient evacuation.