Pursuant to a congressional request, GAO reviewed the Highway Trust Fund, focusing on the: (1) sources and amounts of trust fund revenues generated between fiscal year (FY) 1987 and FY 1991 and their uses; (2) estimated remaining Fund balance when federal-aid highway and mass transit programs expire at the end of FY 1991; and (3) influence that recent legislation could have on surface transportation spending during the next authorization period. GAO found that: (1) federal highway user taxes on motor fuels, tires, and trucks support the Fund; (2) during FY 1987 through FY 1991, those taxes generated about $73.46 billion, with about 64 percent of those revenues generated through gasoline taxes; (3) while the majority of highway tax revenues are credited to the Fund for highway and mass transit projects or related activities, exceptions included cleanups of petroleum-contaminated groundwater and general fund contributions for use in deficit reduction; (4) the Fund will have an estimated uncommitted balance totalling $17.7 billion dollars by the end of FY 1991 if all outstanding commitments authorized through FY 1991 for both highway and mass transit programs are liquidated using the existing cash balance plus the allowed future revenues; (5) Department of Transportation officials recommended a $3.5-billion safety cushion to guard against inaccurate revenue projections, which could reduce the estimated uncommitted available funds to $14.2 billion; (6) recent legislation setting annual discretionary spending limits in separate defense, international, and domestic categories will determine, in part, the actual spending limits for federal-aid highway and mass transit programs through FY 1995; and (7) in FY 1994 and FY 1995, there will be a single cap on all discretionary spending, and highway and mass transit programs will have to compete with all discretionary programs for available funds.

RCED-92-48FS Highway Trust Fund: Revenue Sources, Uses, and Spending Controls

In 2014, governments at various levels spent $165 billion to build, operate, and maintain highways, and they spent $65 billion on mass transit systems. For both types of infrastructure, most of that spending was by state and local governments; about one-quarter of that total came from the federal government, mostly through the Highway Trust Fund. For several decades, the trust fund's balances were stable or growing, but more recently, annual spending for highways and transit has exceeded the amounts credited to the trust fund from taxes collected on gasoline, diesel fuel, and other transportation-related products and activities. Since 2008, in fact, lawmakers have transferred $65 billion from the U.S. Treasury's general fund to the Highway Trust Fund so that the trust fund's obligations could be met in a timely manner. Moreover, with its current revenue sources, the Highway Trust Fund cannot support spending at the current rate. The Congressional Budget Office estimates that spending in fiscal year 2015 for highways and transit programs funded from the Highway Trust Fund will be $44 billion and $8 billion, respectively, whereas revenues collected for those purposes are projected to be $34 billion and $5 billion, respectively. By CBO's estimate, at the end of fiscal year 2015, the balance in the trust fund's highway account will fall to about $2 billion and the balance in its transit account will be about $1 billion. The Department of Transportation (DOT) would probably need to delay payments to states at some point before the end of fiscal year 2015 in order to keep the fund's balance above zero, as required by law. In fact, because of the timing of the deposits to the trust fund, DOT has stated that it would need to delay payments if cash balances fell below $4 billion in the highway account or below $1 billion in the transit account. Then, if nothing changes, the trust fund's balance will be insufficient to meet all of its obligations in fiscal year 2016, and the trust fund will incur steadily accumulating shortfalls in subsequent years.

The federal government spends more than $50 billion per year on surface transportation programs, mostly in the form of grants to state and local governments. Much of this spending is for highways and mass transit programs financed through the Highway Trust Fund. Those programs have an unusual treatment in the federal budget, and the way they are classified in the budget facilitates the spending of more money from the trust fund than there are dedicated revenues to support such spending. Those revenues come from excise taxes on the sale of motor fuels, trucks and trailers, and truck tires, and from taxes on the use of certain kinds of vehicles. This report describes the status of the Highway Trust Fund and options that the Congress might consider to address the imbalance between revenues and spending from the fund. Part of the discussion concerns the transportation programs' unique budgetary classification and how that treatment limits the effectiveness of the standard mechanisms for budgetary control. Tables and figures. This is a print on demand report.