Crazy(?) solution: tax tires instead of gasoline. The tax amount would be a function of tire size since that correlates (via vehicle weight) with wear and tear

Crazy(?) solution: tax tires instead of gasoline. The tax amount would be a function of tire size since that correlates (via vehicle weight) with wear and tear on the roads. To handle early replacement (flat tires, etc.), when tires are replaced, give a rebate based on remaining tread. There would probably be a huge market for illegal tires (similar to illegal cigarettes), so that would require enforcement. You'd also need some way to stop tire theft. Maybe encode the vehicle's license plate number into a chip in the tire or something.