I think most of the cost of local roads is paid for from regular taxes. Not to mention that the capital and maintenance cost of roads depends very heavily on the weight of the vehicles using it. cough trucks cough Freeways are very expensive because the DOT requires them to be able to carry commercial trucks[1].

[1] Santa Clara country, paid to extend HWY85 out of their own pocket and as a result, trucks are banned. Last time I drove it, it was still seemed in good shape after mumble twenty years. Compare with HWY880 though Oakland CA. Always being worked on, always broken up.