Freeway travel time is one of the most useful pieces of information for road users and an important measure of effectiveness (MOE) for traffic engineers and policy makers. In the Greater St. Louis area, Gateway Guide, the St. Louis Transportation Management Center (TMC) operated by the Missouri Department of Transportation (MoDOT), already collects traffic data from more than 700 fixed traffic sensors located along major freeways and arterials. Due to their significant investment in fixed freeway sensors, MoDOT has been striving to more fully utilize this data to extract useful information for stakeholders. One potential application is to convert the information collected by the fixed traffic sensors (point detectors) directly into travel times without the need to install additional sensors. This project developed a database specifically designed and optimized for the purpose of freeway performance measurement and implemented a data quality assurance procedure to examine the quality of the data collected. After a comprehensive literature review, the instantaneous travel time estimation model was selected and implemented in a stand-alone MATLAB-based system and a Microsoft Excel VBA-based tool. Several case studies were conducted to test the applicability of the system. The estimated travel time results were then verified using travel time data collected by a Bluetooth-based method and a video-based manual-vehicle-matching method. This Phase 1 project has proved the feasibility of the proposed approach. The travel time estimation method will be improved and the coverage of travel time estimation expanded to the city’s entire freeway network in Phase 2. (Author/publisher)
Abstract