Evaluation of the OCTA Transit Probe System

The OCTA (Orange County Transit Authority) Transit Probe Project is a field operational test of an automatic-vehicle-location (AVL) system operating in Orange County, California. This report presents the final evaluation results for the project, concentrating on the operational period from June 1, 1998 to May 30, 1999. The report provides a detailed description of the system and the motivation for its design. It provides analyses of data reliability and accuracy, and analysis of the usefulness of transit probe data for predicting automobile travel times. Institutional issues are evaluated, based on interviews with involved personnel, direct observation of meetings and review of project documents. Customer surveys with bus riders and kiosk users are also documented. Bus tracking systems provide many potential benefits, helping: (1) drivers stay on schedule, (2) dispatchers respond to problems, (3) schedulers determine how much time to allocate between schedule check points, and (4) general public know when buses will arrive. Capturing these benefits requires careful planning for operational procedures, data maintenance, and system interfaces and ensuring the equipment itself it reliable. Bus tracking implementations need to involve many parties within the transportation agency, and include task assignments, data transfer methods, and strategies for using information. Because of the small size of the Transit Probe project, along with a competing project within the agency, these factors received only limited attention. As a consequence, the system was not used to a significant degree in the agency.