Dynamic Traffic Assignment Modeling for Incident Management

Dynamic traffic assignment (DTA) has evolved rapidly over the past two decades. This advancement has been fueled by the needs of application domains ranging from real-time traffic operations to long-term planning. DTA models are a natural evolution in the transportation field and are expected to become mainstream when issues related to the realism of their assumptions and mathematical tractability are addressed in greater detail. Several simulation-based DTA models are currently available for real-world deployment and have already gained sophistication and significant acceptability. Simulation tests were conducted on two networks—one representing Birmingham, Alabama, and the other representing Chicago, Illinois—to showcase the DTA capabilities to evaluate the impacts of traffic incidents and to model incident management strategies and relevant intelligent transportation system technologies. The study confirmed that DTA can provide transportation agencies with a powerful tool with which they can improve their existing incident management plans through the evaluation of route diversion strategies, variable message sign placement and content, real-time route diversion, and the production of more comprehensive estimates of incident delay.