EXCEPT THAT ALL ROADS COST MONEY AND NOT ALL ARE TOLL ROADS:

It tolls for thee: Flexibility on highway funding would make all the difference (The Economist, May 20th 2010)

The building and repairing of roads in America is paid for by a federal petrol tax, which replenishes the highway trust fund. Current transport revenues are too puny to cover existing commitments, to say nothing of new initiatives. Only congressional infusions of money from general revenues have prevented the trust fund from going into the red (see chart). Because people are driving less, and cars are more efficient, the petrol tax is not the money-spinner it used to be. But uncertainty, fears about climate change and environmental disasters have not improved the appetite for a rise in the tax rate. It has stayed at 18.4 cents per gallon since 1993. Mr Obama ruled out a petrol-tax increase almost from the beginning of his presidency, saying it would threaten recovery. The administration recently opposed a carbon fee on fuels in a draft Senate climate bill for similar reasons.

State governments, facing budget disaster, have mined other revenue sources, including tolls. Several states are financing new roads by introducing “high-occupancy toll” or HOT lanes, which carpoolers may use for nothing. But HOT lanes are typically built alongside normal lanes. Increasingly, state and local governments want to toll existing lanes, both to limit congestion and to raise funds that could be applied to all aspects of transport budgets. [...]

Tolling is economically efficient: it prices an overused resource (crowded roads). Apart from cutting congestion and raising money, tolls reduce carbon emissions and other pollutants. But Mr Obama has shown no interest in pushing for a change in the interstate tolling rule. Instead, legislators have scrambled to plug funding holes as best they can, primarily through transfers from general revenue. There is no specific reason why transport should be funded by transport revenues alone. But easy opportunities to tax—and thereby reduce—undesirable things are rare. In its current fiscal bind, America cannot afford to miss any.