EBUCK
Yeah, we do. The heavy vehicles, pavement pounders, from bbig SUVs up to trucks, pay more since they burn more fuel. It wouldn't be necessary to track vehicles to get their mileage, either. They read the odometer at inspection time, don't they?
Still, collecting data on vehicle location and speed systemwide could be used in planning for the transportation network, new roads, road maintenance, that kind of thing instead of hiring traffic counters to sit and count vehicles.