A quasi-reversible queue can be associated with certain type of transactions of a Markov chain. It is shown that if Markov chains are coupled in a certain way, then to the resulting chain be associated a queuing network which is itself quasi-reversible and the stationary distribution of the...

This report summarizes the need for (dedicated) radio spectrum for IVHS communication services. It concludes that, if efficient architectures can be developed, several MHz of spectrum will be needed for large-scale introduction of IVHS services. Compared to most other reported estimates of the...

In this paper, the authors discuss the use of vehicles moving in traffic as probes that provide data for estimation and prediction of traffic behavior. The probe vehicles can report data on their speeds, locations, or travel times which can be used by an algorithm that updates estimates of...

This paper documents the development of a communications architecture for Intelligent Vehicle Highway Systems (IVHS) being studied by the California PATH Program. The authors use a layered architecture based on the OSI 7- layer reference model.

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...