Our system was a bit more primitive (well, it is 16 or 17 years old by now so it's definitely not state of the art anymore). We could track our trucks but we had to actively request their position and would only get their current location and no automatic update on that. We also used the system to transmit the tour data to the trucks and communicate with the drivers (like texting on cell phones....and just about as distracting while driving I guess).
However the system was not rooted directly into the trucks telemetric systems so the driver had to transmit fuel data every week manually and I would collect and analyse that data and make reports for the dispatchers about how good or bad their drivers were. I also had to talk to those that had a too low gas mileage (with varying success...
).