The vast majority of damage on the road is caused by vehicles with high axle load, e.g. trucks, especially overloaded trucks. IIRC the damage is proportional to fourth power of the axle load.
As a consequence, personal cars barely register.
It would make sense to collect toll from trucks only, and possibly weigh them all, because overloaded trucks are extra damaging to the road.
To carry this further, of maintenance taxes for roads were structured appropriately, trucks would pay so much that it would be prohibitively expensive to ship across the states in Semis. We'd likely see a resurgence of rail transport.
If we only had trucks on the road, we’d need less road, right? The street where I live could be about a third of the width if it were not for personal cars.
Rhode Island is trying this. The gantries have been up for years, but it was challenged in court by the trucking lobby. The state prevailed with some concessions, and is planning to reinstate the truck tolls soon.
Probably, due to the small size of RI, it will just cause goods not bound directly for RI to divert along I-395 up through CT and MA, and I-290 and I-495 in MA.
As a consequence, personal cars barely register.
It would make sense to collect toll from trucks only, and possibly weigh them all, because overloaded trucks are extra damaging to the road.