Fuel tax and other highway-user revenues collected by the federal government are placed in the federal Highway Trust Fund. Congress allocates these funds to states according to provisions in federal surface transportation legislation-currently the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU), passed in 2005-and annual appropriations bills. Within the executive branch, the U.S. Department of Transportation (U.S. DOT) administers federal funding and programs. Currently, federal funding accounts for about 20 percent of total surface transportation funding in the United States.5 Congress and the U.S. DOT also deal with aviation, ports and other modes of transportation. Other federal stakeholders include land management agencies and environmental protection agencies.