TEVACS: Decision Support System for Evacuation Planning in Taiwan

A microcomputer‐based decision support system is developed for transportation network evacuation applications in Taiwan, the Republic of China. Input to the system mainly includes the trip‐generation‐related attributes, the street network topology and traffic data, the control variables regarding the routing of public transportation vehicles, and the use of traffic control measures. A dynamic network simulation model based on traffic flow theory is used to simulate the vehicles' movement on the street network during the evacuation process. For a given evacuation plan, the network simulation module calculates the estimated network clearance time. The intermediate results of each simulation interval are saved in graphic data files. The planner can use the graphic display module of the system to visually observe the dynamic change of traffic congestion on each link of the network throughout the simulated evacuation process. The system thus provides a convenient tool not only for evaluating different evacuation plans but also for identifying and improving the evacuation bottlenecks on the street network. Application examples of hypothetical cases show that appropriate deployment of public transportation vehicles plus adequate use of traffic control measures can save up to 40% of the network clearance time during an emergency evacuation.