September 2007

Technology Overview

Image shows real-time AVL communications using wireless network for GPS. A GPS satellite relays the position of the bus equipped with an odometer gyroscope to a communications center. The dispatch system at the communications center distributes information to other systems (shown are customer assistance, planning and scheduling, and operations analysis).

Illustration of AVL and real-time communications network.
(Source: Automatic Vehicle Location Successful Transit Applications)

Use AVL to:

Enhance communication between vehicles and control center.
Optimize demand-response scheduling.
Provide real-time traveler information.

Automatic Vehicle Location (AVL) systems calculate the real-time location of any vehicle equipped with a Global Positioning Satellite (GPS) receiver. Data are then transmitted to the transit center with use of radio or cellular communications and can be used immediately for daily operations as well as archived for further analysis.

As a stand-alone technology, an AVL system can be used to monitor on-time performance. When combined with other technologies, AVL can deliver many benefits in the areas of fleet management, service planning, safety and security, traveler information, fare payment, vehicle component monitoring, and data collection. Since the greatest benefits from AVL are achieved by combining it with other Intelligent Transportation System (ITS) technologies, AVL is most appropriate for large rural agencies with more than 30 vehicles that plan to implement a comprehensive ITS.