Dynamic Traffic Assignment Applications for Incident Management

This paper showcases the utilization of a User Equilibrium (UE) Dynamic Traffic Assignment (DTA) model in the Visual Interactive System for Transport Algorithms (VISTA) to support incident management functions. More specifically, the paper presents results from a research case study in Chicago, IL that examined the effect of incidents of varying severity on traffic operations. The VISTA model was executed under a. normal conditions, b. incident conditions without traveler information availability, and c. incident conditions assuming that users had perfect knowledge of the incident conditions and could select paths to avoid the incident location. Incidents ranging from 15 to 120 minutes in duration were simulated and the impact of incident duration on travel time and incident delay was determined. The results confirm that an effective traveler information system can ease the impacts of incident conditions on traffic operations and reduce the incident-induced delays. However, attention should be given to the potential migration effects of rerouting on the operation of neighboring facilities.