Our contractors have a similar setup in all their trucks for the past few years.

Disables the engine if the seat belt isn't plugged in over a certain distance / speed (you need allowances because of rural gates).

Sends a report back to the Supervisors if the speed limit is exceeded by more than 5% for more than 2km.

Pinpoints their position which could be used if you think somebody is slacking off but we use it as a tracking device if they are under duress (injured, lost, etc).

Each tradie has an ID chip that they "sign-on" to the truck with, so if they get a fine it can be sent to the right person.

GPS tracking in hire cars would certainlt change some hirer's habits.