Document Type


Publication Date


Publication Title

International Journal of Transportation


Civil Engineering


Modeling emergency evacuations can help engineers, planners, and emergency managers identify the approximate time it would take for evacuees to leave a disaster area. Unfortunately, many evacuation studies do not account for traffic incidents. This study examined the effect of traffic incidents during a no notice emergency evacuation in the eastern St. Louis metropolitan area road network. The roadway network was modeled using traffic micro-simulation software VISSIM, which utilized the expected traffic volumes that were determined by the regional planning agency, and guided by input from the transportation engineers at the Illinois Department of Transportation (IDOT). Because traffic speeds are expected to be low during such a high-volume event, this study considered only minor incidents. Incident locations were selected based on historical data. The results suggest that minor traffic incidents occurring upstream of key bottlenecks created no significant change in delay or evacuation duration. On the contrary, minor traffic incidents downstream of bottlenecks can significantly increase delay; albeit not enough to delay the duration of the entire evacuation by more than 15 minutes. Thus, during no notice emergency evacuations, traffic managers could prioritize available traffic incident management resources accordingly.