Federal Transportation Funding in Iowa

Information on this web page was last updated in December 2016.

Introduction

Each year in Iowa, a wide range of transportation improvements and operations are carried out by state and local government. Examples include constructing, maintaining and improving highways; improving airports, waterways, and railroads; enhancing aviation, rail, and transit services; and supporting motor carrier safety and enforcement. These activities are funded with a combination of local, state and federal dollars.

Sources of funds

Most federal funds returned to state and local governments come from modal trust funds made up of various federal user fees. Many programs also receive a small percentage from the federal General Fund.

Federal transportation trust fund

Most “federal” transportation funds are actually dollars returned to state and local governments via modal trust funds made up of various federal user fees. Many programs also receive a smaller amount from the federal General Fund.

Federal tax revenue deposited into federal transportation trust funds
FY 2014 - latest available comprehensive data

Trust Fund	Total FY 2014 receipts
Highway Trust Fund: - Highway account - Mass transit account	$40 billion ($34 billion) ($6 billion)
Airport and Airways Trust Fund	$ 13.5 billion
Inland Waterways Trust Fund	$ 0.8 billion

Highway Trust Fund

The largest of the transportation trust funds was established in 1956 to ensure a steady flow of money to support the construction of the nation's interstate system. The Highway Trust Fund (HTF) and user fees have been continued and now support a wide range of transportation programs. User fees include fuel taxes, heavy vehicle use taxes, and retail taxes on purchases of trucks and truck tires. More than ninety percent of the revenue to the HTF comes from fuel taxes. HTF receipts are credited to two accounts: the highway account and the mass transit account. In FY 2014 Iowa contributed $468 million to the highway account (1.37 percent of total national receipts) and $77 million to the mass transit account (1.37 percent of total national receipts).

In addition to the construction, maintenance and improvement of the system of federal-aid highways, the highway account funds a wide range of motor carrier safety and enforcement programs, along with highway-railroad grade crossing programs. The mass transit account provides funds for the construction and operation of bus and rail transit systems.

In recent years, increased fuel efficiency, less driving and other factors have significantly slowed the revenue stream going into the HTF. At the same time, inflation has eroded its buying power and investment levels have increased. The result is a significant HTF deficit, with shortfalls avoided in recent years only with substantial general fund transfers. The most recent, $70.3 billion beginning in December 2015, is expected to generally carry the trust fund through FY 2020, when the current authorization bill, the FAST Act, expires.

Airport and Airways Trust Fund

Revenue to support Federal Aviation Administration programs comes from the Airport and Airway Trust Fund. This fund is generated by passenger ticket taxes, segment taxes, freight taxes, and fuel taxes. Taxes paid by passengers account for nearly seventy percent of revenues; the aviation fuel tax contributes five percent, freight waybills account for four percent, and the international enplanement tax contributes twenty-one percent.

Inland Waterway Trust Fund

The smallest of the transportation trust funds is the Inland Waterways Trust Fund. A tax on barge diesel fuel is the only revenue source for this fund. These funds provide 50 percent of the cost of major capital improvements on the inland waterway system.

Authorization

Congress must give permission for federal funds to be expended. Transportation authorization legislation is the mechanism by which this permission is granted. Authorization legislation establishes transportation policy and areas of emphasis for spending by creating and defining programs and authorizing funding. The funding mechanism, including the various user fees, is established. Authorization legislation covers multiple years because transportation projects require a long time from planning through construction.

Surface transportation

The current multi-year surface transportation authorization act, the Fixing America’s Surface Transportation Act (FAST Act), was signed Dec. 4, 2015 (Pub. Law 114-94). In general, the FAST Act left existing programs intact, and maintained FY 2015 investment levels until Sept. 30, 2020, with small increases for inflation. As mentioned above, these investment levels have been made possible by supplementing Highway Trust Fund revenue with transfers from the General Fund. FAST Act sources for this supplemental funding include: transfers from the Leaking Underground Storage Tank Fund and the Federal Reserve surplus account; revenue from the sale of some crude oil reserves; and savings and increased revenue from changes to certain taxes and penalties, etc. In some cases, ten years’ worth of savings and increased revenue are harnessed to pay for the six-year bill.

Aviation

On Feb. 14, 2012, the president signed a bill reauthorizing federal aviation programs and funding until Sept. 30, 2015. Public Law 112-95 provided $64 billion, including $13.4 billion for the Airport Improvement Program ($3.35 billion per year, a slight decrease from previous years). Most recently, this authorization has been extended to Sept. 30, 2017.

Appropriations

On Dec. 18, 2015, the president signed HR 2029 (Pub. Law 114-113), providing funding through Sept. 30, 2016, for the US DOT and most other federal agencies. For most accounts, formula obligation limitation was set at authorized levels - $42.361 billion for highways, $9.348 billion for transit and $3.35 billion for the Airport Improvement Program. Also included was $500 million for the discretionary TIGER program for FY 2016.

Distribution of funds

Most federal funds are distributed to state and local officials based on formulas. For example, Iowa receives funds to maintain the interstate system based on the state’s share of the nation's interstate vehicle miles traveled and interstate lane miles, while urban planning funds are based on our share of the nation's urban population. Funds for improving our airports are based on the number of passengers, population, and geographic area of the state; and a portion of the five-year capital improvement plan for general aviation airports. Transit funding is based in part on transit ridership. These formula funds are called apportionments. Other programs have no mandatory distribution formula, so distribution is based on competitive applications or another project selection process. These funds are called allocations. In general, as a condition of receiving federal funding the state or local jurisdiction is required to provide matching dollars. The most common matching requirement is twenty percent, but it can be as low as zero percent or as high as fifty percent.

Formula transportation funding for Iowa

The following table identifies the level of federal FY 2014-FY 2016 formula funding received by Iowa for state and local projects and activities.

Projects/Programs	FY 2014		FY 2015		FY 2016
	Iowa total	Percent of national	Iowa total	Percent of national	Iowa total	Percent of national
Highway projects	$474.3 M	1.25%	$474.3 M	1.25%	$498.5 M	1.25%
Transit projects	$39.9 M	0.38%	$38.4 M	0.36%	$39.5 M	0.34%
Airport projects	$23.9 M	.75%	$50 M	1.56%	N/A	N/A

Questions?

For specific funding program information, review the Iowa DOT's Funding Guide.