Corridor-Based Forecasts of Work-Zone Impacts for Freeways

This project developed an analysis methodology and associated software implementation for the evaluation of significant work zone impacts on freeways in North Carolina. The FREEVAL-WZ software tool allows the analyst to predict the operational impacts of work zones, including impacts from capacity reductions, lane closures, reduced speed limits and traffic diversions. The research is based on the 2010 Highway Capacity Manual Freeway Facilities methodology and its companion FREEVAL-2010 computational engine. Through this project, the tool was enhanced to allow for work-zone specific impact assessment, customized to the needs of the NCDOT Traffic Management Unit. The tool includes a new planning-level feature that enables a quick assessment of work zone impacts, while still allowing for a more detailed operational analysis. The tool uses default values for work zone inputs specific for North Carolina conditions. However, all inputs can be adjusted by the user. Further, the methodology allows the analyst to calculate user cost impacts of the work zone. All calculations and algorithms in FREEVAL-WZ are consistent with the methodologies in the 2010 Highway Capacity Manual. The project included a significant field validation and model calibration efforts with operational data collected directly by NCDOT using field sensors. The data was used to compare predicted model performance to field operations and to develop default parameters for typical North Carolina work zone configurations. Project deliverables include a final report, the actual FREEVAL-WZ tool, and a software user manual.