Evaluation of Traffic Flow Analysis Tools Applied to Work Zones Based on Flow Data Collected in the Field

The Ohio Department of Transportation (ODOT) has identified the maintenance of traffic (MOT) as a top priority to serve the motoring public as part of a department strategic initiative. A key component of this strategy is to ensure that traffic flows efficiently through work zones. This paper describes work that was performed for ODOT to determine if commercially available traffic simulation models could be calibrated to yield accurate queue length and delay time predictions for planning purposes in freeway work zones. Four work zones on multi lane freeways were selected by ODOT for collection of the calibration data. Traffic flow video records were obtained at the four selected work zones using two ODOT video recording vans equipped with 15 m masts. Traffic flow parameters were extracted from the video records using the Mobilizer-PC software package. The traffic simulation/prediction tools that we investigated included the Highway Capacity Software (HCS), Synchro, Corsim (under ITRAF and TRAFVU), NetSim, and a macroscopic model called QueWZ92. Simulation models were constructed with all models for the selected work zones, and the simulated queue lengths and delay times were compared to the data that was extracted from the field data with Mobilizer-PC. The results of this study indicated that the microscopic simulation packages could not be calibrated to the oversaturated conditions that existed at the work zones. The calibrated microscopic simulation packages underestimated the actual length of the queues that formed in the real world. The macroscopic QueWZ92 produced more accurate estimates than the microscopic packages.