An automatic vehicle locator (AVL) is a device that makes use of the Global Positioning System ( GPS ) to enable a business or agency to remotely track the location of its vehicle fleet by using the Internet. These devices combine GPS technology, cellular communications, street-level mapping, and an intuitive user interface, with the ostensible goal of improving fleet management and customer service. For example, a company using an AVL system is able to pinpoint the longitude, latitude, ground speed, and course direction of a given vehicle. The vehicle's location can be quickly found and it could be rerouted to provide timely delivery to a nearby customer. AVL systems also enable companies to structure delivery routes more efficiently by compiling a database of vehicle information, including location of customers in relation to established delivery routes.
AVL systems generally include a network of vehicles that are equipped with a mobile radio receiver, a GPS receiver, a GPS modem, and a GPS antenna. This network connects with a base radio consisting of a PC computer station as well as a GPS receiver and interface. GPS uses interactive maps rather than static map images on the Web. This means users can perform conventional GPS functions such as zoom, pan, identify and queries.
AVL systems can be used to increase the accountability of field personnel and boost the efficiency of a company's dispatching procedure. Dispatchers can get a real-time snapshot of driver adherence to a route, provide customers with an estimated time of arrival, and communicate directly with drivers. Public safety agencies, such as police department or fire departments, can use AVL technology to improve response times by being able to dispatch the closest vehicles for emergencies.
Most AVL suppliers have created products that don't require dedicated servers and require minimal training of dispatchers. AVL systems use mouse clicks instead of keystrokes to page a single vehicle, a designated group of vehicles or an entire fleet. The Aertrax system, for example, operates without expensive receivers or other equipment. It can be operated with a PC or desktop that connects to the Internet. Aertrax includes a completely self-contained unit that uses a minimal amount of power from the vehicle in which it is installed. This unit transmits GPS location data, either on a regularly timed basis or in response to a command. This data is then converted into mapping that is instantly available via the Internet.
In Corpus Christi, Texas, a regional transit authority is collaborating with Texas A&M University-Corpus Christi to develop an AVL system that not only would enable it to track bus locations but also enable automated ridership data collection and dynamic routing. Until recently, the availability of GPS to the commercial and civil sectors had been controlled by the U.S. Department of Defense through an internationally imposed degradation standard known as Selective Availability. This standard degraded the accuracy of civilian GPS so that the highest degree of accuracy was reserved for the military. SA restrictions have since been lifted, enabling GPS to be dispersed for commercial application.