But I think the road system is the only part of the current system that makes sense. We pay for roads at the pump via gas taxes. The heavier your vehicle the more fuel you purchase and the more wear and tear you cause. So it is not a forced system at all. If you don't want to pay, then don't buy fuel, and consequently don't drive. It certainly is not a perfect system but it is as fair as anything the government does.
As someone stated above, the system is already there.
And governments don't build roads, they just acquire land and procure contracts for the construction (always low bid for transportation infrastructure), and contract out design.