PeMS 4 is the latest of four task orders devoted to research, development, and maintenance of the PeMS system. PeMS collects, processes, stores, and makes available online data from the six Caltrans districts (D3, 4, 7, 8, 11, 12), which include the major urban areas in California. The data are...

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...

This paper considers the issue of safety in Automated Vehicle Highway Systems (AVHS). An approach is proposed for proving that a system is safe. The design for a proposed AVHS is considered and shown that if the physical controllers in the vehicles satisfy a set of constraints then the AVHS is...

This continuing PeMS project had four tasks: 1. Quantify the reduction in delay from optimum freeway operations; 2. Release travel time estimates to the public; 3. Training Caltrans staff in the use of PeMS; 4. Improve system robustness/maintenance. For task 1, we developed and implemented an...

An algorithm for real time estimation of truck traffic in multi-lane freeway is proposed. The algorithm uses data from single loop detectors-the most widely installed surveillance technology for urban freeways in the US. The algorithm works for those freeway locations that have a truck-free...

In this report we present a framework to assist Intelligent Transportation Systems (ITS) providers in the deployment of ITS user services requiring wide-area wireless communi-cations. We examine a scenario in the San Francisco East Bay Area for the 1995 time frame and determine the applicable...