As you can imagine many of these large fleets, especially in government, have vehicles numbering in the thousands for just a single fleet. All these vehicles will be collecting large amounts of positioning data that can be integrated with existing map data for route optimization, mileage reports, asset location, idle reports, delivery schedules and beyond. Most tracking solutions currently output reports in a text, excel or some
type of graphical format overlaid on existing maps such as Google Earth or Bing maps. An integration into existing GIS will be inevitable.
Future tracking systems will surely combine sensors, cameras, and even laser scanners to collect even more data as delivery drivers, trash collectors, road maintenance crews and others drive their routes as they knowingly (or unknowingly) collect data used for other purposes. This is already happening I'm sure, at what level or scale I don't know.
I believe it is important to keep up to date on this sector of the GPS market as many in the industry are already.
Are you currently using a fleet tracking system to collect data for GIS integration?