Everybody, there are two functions that GPS is available for. The first is using the bulls-eye to know if you are sheeting a package at the location that PAS thinks it needs to go. that's live, realtime, and enable for an entire center (usually). All this function does it try to catch the RARE instance where a driver is at an address that doesn't match the package.
The second is tracking your route. this is not realtime. It's usually enabled on a loop by loop basis and all that happens it the GPS in the DIAD records waypoints every few minutes and when you sheet a package. Then when you get back to the center the DIAD uploads that along with your timecard (and mobile communication records) the next day, the center team can play back your trace (if they figure out how, the people who wrote that interface, never studied user interface design in their lives)
If they see that your route has you going around in circles and or doing other crazy things, then they can go to IE and try to clean up the loops.