Improving Operations Using Advanced Surveillance Metrics and Existing Traffic Detectors

1 OVERVIEW Because travel time provides information over an extended freeway link, rather than at a single point, it is a key parameter for ATIS applications and it is a powerful tool for ATMS. Under PATH sponsorship, we have already developed a prototype travel time measurement system that utilizes existing dual loop speed traps and "model 170" controllers. This research has advanced the work by improving the vehicle reidentification algorithms (Sections 2 and 3) and applying the travel time measurement system over seven freeway links in real-time (Section 4). This latter work was conducted as part of the Berkeley Highway Laboratory (BHL). The detector data are passed on to Caltrans District 4 operations and archived for subsequent research. In addition to the previous work, which uses data from two or more detector stations to measure travel time, we have conducted a pilot study to estimate link travel time using data from a single detector station. The estimation work was conducted in conjunction with MOU 3000 and the results are presented in Traffic Data Measurement and Validation, MOU 3000 Final Report.