This paper develops a new methodology for deriving an empirical fundamental relationship from vehicle detector data. The new methodology seeks to address several sources of noise present in conventional measures of the traffic state that arise from the data aggregation process, e.g., averaging...

Efficient management of a road network requires continuous decision-making based on conditions on the network and an understanding of the impacts of the decisions made. These conditions are usually measured with fixed-point surveillance systems, most of which are deployed in such a manner as to...

Traffic detectors support most traffic management applications, so it is important that a detector performs as expected. This study evaluates the performance of four loop sensor models and the Remote Traffic Microwave Sensor (RTMS), adding to the body of sensor performance knowledge through the...

This document is the final report for the 2003 Berkeley Highway Laboratory (BHL) project that is part of the University of California's PATH program and supported by the California Department of Transportation (Caltrans). The primary objectives of this project have been to maintain, improve, and...

This paper presents evidence that the commonly used point bottleneck model is too simplistic for freeway bottlenecks, the actual mechanism appears to occur over an extended distance. We find evidence of subtle flow limiting and speed reducing phenomena more than a mile downstream of a lane drop...

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...

Loop detectors are the preeminent vehicle detector for freeway traffic surveillance. Although single loops have been used for decades, debate continues on how to interpret the measurements. Many researchers have sought better estimates of velocity from single loops. The preceding work has...

This report presents a vehicle reidentification algorithm for consecutive detector stations on a freeway, whereby a vehicle measurement made at a downstream detector station is matched with the vehicle's corresponding measurement at an upstream station. The algorithm should improve freeway...