Well, after all, the whole point of these tires is to dig into the "road" to get better traction than is possible with normal friction, so it's not too surprisi

Well, after all, the whole point of these tires is to dig into the "road" to get better traction than is possible with normal friction, so it's not too surprising that they dig in to a lesser extent on hard surfaced roads. That said, this type of tire is a very tiny fraction of the total miles driven on public highways, and so if you're looking for someone to tax based on the costs they create, it's all heavy trucks.