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).

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

Use AVL to:

Optimize scheduling and dispatching in real time.
Enhance onboard safety and emergency response.
Refine cost allocation among supporting agencies.

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 determine where vehicles are located and to monitor on-time performance. Combined with other technologies, AVL can deliver many benefits in the areas of fleet management, service planning, traveler information, and cost allocation. Since the greatest benefits are achieved by combining AVL with other Intelligent Transportation System (ITS) technologies, AVL is most appropriate for large human services agencies or brokerages with more than 50 vehicles that plan to implement a comprehensive ITS.