ITS Research Program, UW

Publication Title:
Automatic Transit Location System

The Automatic Transit Location System project had two goals: (1) to perform a state-of-the-art review of Automatic Vehicle Location (AVL) technologies and (2) to create an Advanced Public Transportation System (APTS) prototype using King County Metro AVL data. At the time of this proposal, Metro used AVL data solely for internal fleet management. With the completion of this project, we have demonstrated that the same source data that drives Metro's management system can be repackaged for traveler information services, without affecting Metro's existing use of the data. This model is one which, if pursued as a regional strategy, will lead to significantly enhanced regional cooperation through a rich, open network of ITS resources.

Research Approach:

Five processes compose the prototype system architecture. These processes are performed on several different computers that are located in various physical areas and connected by the Internet. Within these computers exist dedicated servers that handle each specific process. The prototype consists of Metro's odometery- based AVL system; WSDOT's loop-based freeway system; an AVL instance server, which puts the AVL odometery data on the ITS network; a loop instance server, which puts the freeway loop data on the ITS network (constructed under another project); an AVL fusion server, called the positioning server, which converts the AVL odometery data to latitude and longitude pairs; and a GIS application that displays, in real time, both bus locations and freeway congestion on a digital map.

Conclusions and Recommendations:

This project accomplished two significant tasks. First, a state-of-the-art review of AVL technologies was undertaken and is presented in the second chapter of the report. This state-of-the-art review is used to present the King County Metro AVL system in the context of possible AVL technologies. The Metro AVL system was used solely for internal fleet management prior to this project.

The second accomplishment was to demonstrate the use of real-time transit information derived from the Metro AVL system to produce a prototypical display of real- time transit coach locations suitable for wide area Advanced Traveler Information System (ATIS) use. This project further demonstrated the viability of combining multi-agency data with different technology roots in a single development environment that encourages interagency collaboration in the creation of ITS applications and services.

The rich and flexible development environment, generated at the University of Washington and used to leverage a proprietary AVL system to a public ATIS prototype, is a major advantage provided by a regional ITS infrastructure and should be incorporated into state plans under Venture Washington.