AVL, CAD, and Real-Time Passenger Info for Beginners

Real-time Automated Vehicle Location (AVL) has now become a commodity product. Unfortunately, some companies are using commodity as an excuse to pass off incomplete or unsuitable products to unsuspecting buyers.

This series introduces the concept of AVL and its extensions, Computer Aided Dispatching (CAD) and Real-Time Passenger (or Customer) Information (RTPI). Each of the following sections introduces a key component. The goal of these posts is not to convey mastery, but to get an idea of the right questions to ask. For a more generic introduction see TransitWiki.

The components I will cover are:

Location locates a vehicle,
Communication carries locations to a server
Assignment informs about on what that vehicle is doing,
Dispatcher User Interfaces are used to managing service,
Passenger User Interfaces help passengers, and
APIs allow developers to connect systems and build new interfaces.
Monitoring systems help the operators keep the system up and running.

The difference between AVL, CAD/AVL, and RTPI products is the combination of these components. I’ll refer to a solution that includes all of them as the “Full Stack”. You’ll find their definitions below the fold.

Components that make up AVL, CAD, RTPI, and the "Full Stack"