This report presents the results of an evaluation of a prototype automatic vehicle identification (AVI) system for the Puget Sound area. AVI can identify and locate specific vehicles at a precise location.
We chose to investigate a loop-based AVI system, primarily because the Puget Sound-area freeway system has numerous inductive loop detectors already in place, and we expected that the current method of collecting traffic data could be augmented by an AVI system. However, before implementing any large-scale AVI system, we first wanted to test a small-scale, prototype system based on technology that piggy-backs AVI detectors on existing loop detectors.
The tests revealed a failure to detect buses at the rate of nearly one-in-five expected detections. While the exact cause or causes of the failures are not completely clear, we suspect the loop system itself to have been a prime contributor to the failures. We recommend further testing and troubleshooting to help determine the viability of the AVI system. We also recommend implementing and testing a method for remote access of AVI data.
Assuming that the technical difficulties can be solved (or that a nearly one-in-five detection error rate is acceptable), there are potential applications of loop-based AVI technology in the Puget Sound region. These include (1) performance monitoring of HOV lanes, (2) regulation of HOV lane use, (3) real-time location data for advanced public transportation systems, and (4) transit fleet management.