The Texas Department of Transportation (TxDOT) TransGuide System located in San Antonio, Texas, includes an implementation of in-vehicle navigation using real-time traffic data. Southwest Research Institute (SwRI) developed and is currently deploying this In-Vehicle Navigation (IVN) system for TxDOT under the Federal Highway Administration Model Deployment Initiative (MDI). The system broadcasts data using a commercial FM radio station subcarrier. Link speed, incident, and lane closure information is communicated using a protocol that includes geographically based location references. These location references help to minimize dependencies between map databases used by different system components. As part of the program, SwRI is equipping 590 vehicles with in-vehicle navigation units supplied by two manufacturers.
Abstract