This study investigated the use of a real-time knowledge-based decision support tool (Traffic Control Manager) to assist traffic operations center (TOC) personnel with selection of alternative traffic control plans after the occurrence of nonrecurring congestion. The ability of Traffic Control Manager to reduce delay during nonrecurring congestion was tested using the Dynasmart simulation model (Dynamic Network Assignment Simulation Model for Advanced Road Telematics) to measure average and total network travel time and stop time for scenarios "with" and "without" Traffic Control Manager.

The transportation sub-network input into the Dynasmart simulation model represented the Disney Land area of Anaheim, California. Actual traffic count data was input into the model to represent baseline saturation levels corresponding to high, medium, and low attendance levels at Disney Land. Each simulation had a two hour time horizon, and a total of 10 scenarios were run "with" and "without" the decision support tool. Scenarios included variations in attendance level, incident location (no incident, freeway, arterial), incident duration (10, 30, 60 minutes), capacity reduction (30 to 80 percent), and the changeable message sign (CMS) compliance rate (50 to 100 percent).