Innovations in Oregon’s Work Zone Traffic Analysis Program

This paper describes how the State of Oregon is being challenged with historic construction needs over the next 10 years. Keeping traffic and freight moving during this time of unprecedented construction is one of the top priorities of the Oregon Department of Transportation (ODOT). This paper summarizes ODOT’s established work zone traffic analysis practices and the development of new methodology for estimating and managing individual project and corridor work zone delays. ODOT’s established work zone traffic analysis methodology is designed to predict the hours during which lanes or shoulders can be safely closed, and the approximate traffic queue length and resulting delays that would develop during such closures. The new methodology began with ODOT’s established work zone traffic analysis practices and existing data sources for traffic characteristics. This methodology was augmented by CORSIM and regression analysis principles which were used to develop volume vs. delay curves. The resulting methodology is used to predict lane closure windows, expected queuing and approximate delays during any hour of any month of the statewide construction program. The new methodology has been organized into a compilation of spreadsheets that are designed to automate analysis calculations. The methodology makes it possible to report nearly instantaneous lane closure windows and work zone delays. The report data can be used for a group of projects on highway segments for a number of different work zone scenarios for any analysis year. The paper discusses observations and lessons learned during the extensive data collection process required to establish base conditions and to calibrate the statewide work zone analysis model as well as the future direction of the work zone traffic analysis program.