Disproving the User Toll Theory

User toll means that drivers have to pay money to cover road cost, just like eaters pay money to cover food cost. This paper first shows that the U-shaped cost theory supports such toll, but the corresponding functions are neither demand nor supply. Then, it separates the U-shaped cost theory into two: A variable cost theory to uproot the user toll mindset and to derive a positive traffic supply; A fixed cost one to evaluate the worthiness of a road. After the correct assessment for public roads is derived, this paper disproves toll-cum-tax. It also corrects many economics misunderstandings.