Validating the Performance of the FHWA Work Zone Model Version 1.0: A Case Study Along I-91 in Springfield, Massachusetts

Central to the effective design of work zones is being able to understand how drivers behave as they approach and enter a work zone area. States use simulation tools in modeling freeway work zones to predict work zone impacts and to select optimal design and deployment strategies. While simple and complex microscopic models have been used over the years to analyze driver behavior, most models were not designed for application in work zones. Using data collected from an instrumented research vehicle and model components from two PhD dissertations, FHWA created the Work Zone Driver Model and programmed the Work Zone Driver Model DLL v1.0, a software that could override car-following in commercial microsimulation software packages so that pracitioners can better predict work zone impacts. This paper demonstrates the capabilities of the FHWA Work Zone Driver Model DLL v1.0, interfaced with VISSIM, and tested on an interstate work zone in Springfield, MA. The DLL’s performance is compared to field data collected using an instrumented research vehicle (IRV) and to Weidemann 99 in VISSIM. Performance metrics were selected to align with state DOT work zone management efforts. Results showed acceptable performance from the DLL, as it predicted queue locations and travel speeds that were near field observations. Limitations of the DLL and interface are discussed, and opportunities for improving version 2.0 are described.