LOCATOR Automatic vehicle location (AVL) is a computer -based vehicle tracking system. For transit, the actual real -time position of each vehicle is determined and relayed to a control center. Actual position determination and relay techniques vary, depending on the needs of the transit system and the technologies employed. Transit agencies often incorporate other advanced system features in conjunction with AVL system implementation. Simple AVL systems include: computer -aided dispatch software, mobile data terminals, emergency alarms, and digital communications. More sophist icated AVL Systems may integrate: real-time passenger information, automatic passenger counters, and automated fare payment systems. Other components that may be integrated with AVL systems include automatic stop annunciation, automated destination signs, Vehicle component monitoring, and Traffic signal priority. AVL technology allows improved schedule adherence and timed transfers, more accessible passenger information, increased availability of data for transit management and planning, efficiency/productivity improvements in transit services .

What is AVL technology?

Automated Vehicle Locator (AVL) systems use satellite and land communications to display each vehicle's location, status, heading, and speed on the computer's screen. AVL systems use one of four types of navigation technology, or may combine two of these technologies to compensate for inevitable shortcomings of any one technology. The four principal technologies employed for AVL systems are:

1. Global Positioning System 2. Dead-Reckoning System 3. Signpost/Odometer Systems 4. Radio Navigation/Location

Buses equipped with AVL offer many possibilities for transit interface with highway and traffic organizations or transportation management centers. Opportunities include: providing transit buses with traffic signal priority; obtaining traffic congestion data at the dispatch center to allow rerouting of buses or informing customers of delay; incorporating transit information in traveler information systems; developing multi -application electronic payment systems; using buses to automatically communicat e traffic speed; and reporting of roadway incidents by transit vehicle operators.