For more than half a century, the United States adhered to the user fee principle in financing its transportation infrastructure; designing systems in which users, not the general public, paid for the construction and maintenance of roads. Under this principle, the federal government relied heavily on a fuel tax to support the cost of its highway system. Revenues from the tax go into the federal Highway Trust Fund, which is independent of the General Fund; and every five years or so Congress passes an authorization bill to allocate these revenues. At the state level, similar mechanisms have been in place for decades, though tax rates vary from one jurisdiction to the next. In recent decades, this funding mechanism has faced a variety of challenges. Increased awareness of local air pollution and traffic congestion has given rise to the accusation that motorists do not pay for the higher health and economic costs that they incur. Increasingly the U.S. transportation sector, as a major contributor to greenhouse gas emissions and consumer of oil imports, is also under pressure to shoulder its fair share of the costs to mitigate climate change and promote energy security.
Huang, Edward, Henry Lee, Grant Lovellette, and Jose Gomez-Ibanez. "Transportation Revenue Options: Infrastructure, Emissions, and Congestion." Belfer Center for Science and International Affairs Discussion Paper 2010-13, September 2010.