Funding Federal-aid Highways

Publication No. FHWA-PL-17-011

January 2017

Office of Policy and Governmental Affairs

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Contents

1. Introduction...........................................................................................................................................1

Key terminology ....................................................................................................................................1

Structure of this report...........................................................................................................................3

2. Authorization of Funding......................................................................................................................5

Authorization act ...................................................................................................................................5

From bill to law......................................................................................................................................8

Budget authority..................................................................................................................................12

Homes for Federal highway law ..........................................................................................................14

3. Distribution of Funding ......................................................................................................................15

Apportionments...................................................................................................................................15

Allocations...........................................................................................................................................19

Rescission...........................................................................................................................................19

Sequestration......................................................................................................................................20

4. Obligation of Funding.........................................................................................................................23

What is an obligation?.........................................................................................................................23

Availability...........................................................................................................................................23

Federal share......................................................................................................................................24

Appropriations act ...............................................................................................................................26

Federal budget process.......................................................................................................................26

Other appropriations ...........................................................................................................................29

5. Obligation Limitation ..........................................................................................................................31

History.................................................................................................................................................31

Function and characteristics................................................................................................................32

Distribution..........................................................................................................................................33

Lop-off.................................................................................................................................................34

6. Outlay of Funding ...............................................................................................................................37

Conditions precedent ..........................................................................................................................37

Payments to States .............................................................................................................................37

Rate of outlay......................................................................................................................................39

7. The Highway Trust Fund ....................................................................................................................41

History and legal authorities ................................................................................................................41

Sources of income ..............................................................................................................................42

Collection of taxes...............................................................................................................................45

Trust Fund operations .........................................................................................................................46

Significance of the balance .................................................................................................................47

Byrd Test.............................................................................................................................................47
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Appendices ............................................................................................................................................... 49

A. Glossary ........................................................................................................................................... 50

B. FAST Act authorizations ................................................................................................................... 52

C. Apportionment and programmatic distribution .................................................................................. 54

D. Penalties applicable to the Federal-aid highway program ................................................................ 56

E. Sub-State distribution of Surface Transportation Block Grant Program funding .............................. 60

F. Sub-State distribution of Transportation Alternatives funding ........................................................... 61

G. Transferability of apportioned funding .............................................................................................. 62

H. Federal share ................................................................................................................................... 63

I. Distribution of the Fiscal Year 2016 obligation limitation ................................................................... 66

J. Lop-off from allocated programs ....................................................................................................... 67

K. Historical Federal fuel tax rates ........................................................................................................ 68

Endnotes ................................................................................................................................................... 72

Figures 

 1. Lifecycle of Federal-aid highway funding .......................................................................................... 3 

 2. Enactment of an authorization act .................................................................................................... 8 

 3. Comparative lifecycles of appropriated budget authority and contract authority ............................ 12 

 4. Typical period of availability for Federal-aid highway funding ......................................................... 24 

 5. Federal budget process .................................................................................................................. 27 

 6. Payments to States ......................................................................................................................... 38 

 7. Rate of outlay of Federal-aid highway funding ................................................................................ 39 

Tables 

 1. Extensions to authorizations acts ..................................................................................................... 6 

 2. Jurisdiction over surface transportation authorization ....................................................................... 9 

 3. Amounts sequestered under the Budget Control Act of 2011 ......................................................... 22 

 4. Jurisdiction over the Federal budget and surface transportation appropriations ............................ 28 

 5. Impact of FY 2016 obligation limitation on availability of funding .................................................... 32 

 6. Expiration of Highway Trust Fund-related authorities ..................................................................... 42 

 7. Current Highway Trust Fund tax rates ............................................................................................ 44 

 8. Transfers to ensure Highway Trust Fund solvency ......................................................................... 45 

 9. Operation of the Highway Account, FY 2015 .................................................................................. 46 

 10. Calculation of initial FY 2016 Byrd Test .......................................................................................... 48 
1

1. Introduction

ecause of a continuing demand for information concerning the funding of 

Federal-aid highways, the Federal Highway Administration (FHWA) 

prepared a report, “Financing Federal-Aid Highways,” in January 1974 to 

describe how Federal-aid highways are funded. The FHWA modified and updated 

this report in July 1976, May 1979, October 1983, November 1987, May 1992, 

August 1999, March 2007, and January 2017. The FHWA prepared these updates 

following enactment of new highway or surface transportation acts to reflect

changes made by those acts.

This latest update of the report incorporates changes in funding procedures brought 

about by the 2012 enactment of Public Law 112-141, the Moving Ahead for 

Progress in the 21st Century Act (MAP-21) and the 2015 enactment of Public Law 

114-94, the Fixing America’s Surface Transportation (FAST) Act. With this update 

comes a new title—“Funding Federal-Aid Highways”—that more accurately 

reflects the report’s content and focus.

As with previous versions, this report follows the fiscal process from inception in 

an authorization act to payment from the Highway Trust Fund and discusses the 

congressional and Federal agency actions that occur throughout that process.

The four “As” and two “Os”. This report, and the Federal-aid Highway 

Program (FAHP) more broadly, relies heavily on a few key terms:

• Authorization. The term “authorization” is typically used in the context of 

an authorization bill or act (law): substantive legislation that establishes or 

continues Federal programs or agencies and establishes an upper limit on 

the amount of funds for the program or programs. Within such an act, the 

term may also refer to the program-specific upper limit.

• Appropriation. The term “appropriation” is typically used in the context 

of an appropriations bill or act: a law that typically makes funds available 

for obligation and expenditure with specific limitations as to amount, 

purpose, and duration. 

• Apportionment. For the purposes of this publication as it relates to funding 

Federal-aid highways, the distribution of funds to States as prescribed by a 

statutory formula.1

• Allocation. For purposes of this publication as it relates to funding 

Federal-aid highways, an administrative distribution of funds for programs 

that are not distributed to States by a statutory formula.

• Obligation. The Federal government’s legal commitment (promise) to pay 

or reimburse a State or other entity for the Federal share of a project’s 

eligible costs.

B

Key terminology
2

• Outlays. Actual cash (or electronic transfer) payments made to the State 

or other entity to pay the entity for eligible costs incurred. Outlays 

generally are provided as work progresses for the Federal share for 

approved highway program activities.

The report discusses each of those terms in greater detail in the coming chapters, 

and appendix A provides a more complete glossary of FAHP-related terminology. 

Use of the term “State”. The overwhelming majority of Federal highway 

funding is distributed to (and used by) States—a term that in this context 

encompasses both Puerto Rico and the District of Columbia. However, there are 

other non-State recipients of Federal highway funding, such as selected U.S. 

territories and other Federal agencies.

The Department and its operating administrations. The Department of 

Transportation encompasses nine “operating administrations,” each of which deals 

primarily with a specific mode (or aspect) of transportation. In addition to FHWA, 

this includes the Federal Aviation Administration (FAA), Federal Motor Carrier 

Safety Administration (FMCSA), Federal Railroad Administration (FRA), Federal 

Transit Administration (FTA), Maritime Administration (MARAD), National 

Highway Traffic Safety Administration (NHTSA), Pipeline and Hazardous 

Materials Safety Administration (PHMSA), and the Saint Lawrence Seaway 

Development Corporation. This report uses the respective acronym when referring 

to one of these operating administrations.

Acronyms for surface transportation authorization acts. This report refers 

throughout to a variety of surface transportation authorization laws, including each 

of those listed below (shown in the order in which they were enacted). When 

discussing one of these laws, the report relies on the law’s respective acronym.

• Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA).

• Transportation Equity Act for the 21st Century (TEA-21).

• Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy 

for Users (SAFETEA-LU).

• Moving Ahead for Progress in the 21st Century (MAP-21).

• Fixing America’s Surface Transportation (FAST) Act.
3

The Federal-aid funding lifecycle follows a step-by-step process. As with a 

construction project, each step builds upon the previous step.

Figure 1 shows the major steps in the lifecycle of Federal-aid highway funding.

Figure 1. Lifecycle of Federal-aid highway funding.

The structure of this report largely parallels the Federal-aid highway funding 

lifecycle. Chapter 2 lays the foundation: the authorization process for the FAHP

and the contract authority that it creates. Chapter 3 describes how FHWA 

distributes the authorized funding. Chapter 4 describes how and when FHWA 

obligates funding at the request of funding recipients (most often States), as well as 

the Federal budget process and the role of the annual appropriations act. Chapter 5 

focuses on the portion of the appropriations act that most impacts the Federal 

program: an annual obligation limitation. Chapter 6 wraps up the highway funding 

lifecycle with an examination of the outlay of funding. Finally, Chapter 7 

discusses the history and operations of the Highway Trust Fund, which funds the 

entirety of the FAHP.

The report ends with appendices that provide greater detail on a number of topics 

mentioned in individual chapters. 

Structure of this 

report

5

2. Authorization of Funding

very Federal program or activity, including the Federal-aid Highway 

Program (FAHP), requires legal authority to operate. The authorization act 

provides that authority, along with related funding, as this chapter will 

discuss.

It is critical to understand the meaning of the word “program.” First, “program” is 

used as an umbrella term referring to activities administered by FHWA. When this 

report uses “program” in this all-encompassing sense, it will use the term “Federalaid Highway Program,” or “FAHP.” Second, “program” also refers to any one of 

the separately funded categories that make up the overall FAHP. For example, the 

National Highway Performance Program (NHPP) and the Surface Transportation 

Block Grant Program (STBG) each have their own specific and separate funding; 

consequently, each is considered a program.

In addition to having its own distinct and separate funding, each program has

associated with it certain activities for which that funding may be used. These are 

described in law and are referred to as eligible activities. These activities, often 

eligible under a number of programs, are not considered programs in the financial 

sense of the term as used in this report because the legislation does not single out 

these activities for specific funding.

Overview. The first and most crucial step in funding the Federal-Aid Highway 

Program is development of authorizing legislation. An authorization is a statutory 

provision that establishes or continues a Federal agency, activity, or program, and 

can be for either a fixed or indefinite period of time. A surface transportation 

authorization act also provides unique funding for the FAHP through a special type 

of Federal budget authority (contract authority) discussed later in this chapter. The 

funding of other Federal programs may be much more dependent on a second 

legislative act, known as an appropriations act, than on authorizing legislation. 

Chapter 4 discusses appropriations acts and their impact on the FAHP. 

In addition to authorizing programs and funding, a surface transportation 

authorization act typically includes a “revenue title.” This is the portion of the law 

that enables the operation of the Highway Trust Fund (HTF) and provides the 

revenues to support the programs contained in the act. 

History of authorization acts. Authorizing legislation for highways began with 

the Federal-Aid Road Act of 1916 and the Federal Highway Act of 1921. These 

acts provided the foundation for the FAHP as it exists today. A series of multi-year 

authorization acts have subsequently continued the FAHP. Since 1978, Congress 

has passed highway authorization legislation as part of larger, more 

comprehensive, multi-year surface transportation acts. For example, in 2015, 

Congress enacted the FAST Act. The FAST Act included titles related to Federalaid highways, innovative project finance, public transportation, transportation 

E

Authorization act
6

safety, innovation, hazardous materials transportation, multimodal freight 

transportation, rail transportation, and a newly-established National Surface 

Transportation and Innovative Finance Bureau. 

Surface transportation authorization acts vary in scope and duration. The most 

significant surface transportation acts are major multi-year laws. For example, 

ISTEA, enacted in 1991, TEA-21, enacted in 1998,2 SAFETEA-LU, enacted in 

2005, and the FAST Act, enacted in 2015, each covered a span of five or more 

fiscal years. In contrast, MAP-21, enacted in 2012, covered two years.

A surface transportation authorization act may also be enacted as a stop-gap 

funding bill, designed to extend the program and keep it operational while 

Congress debates more comprehensive authorizing legislation. Congress has 

passed a number of such “extension acts” during each of the previous several 

reauthorization cycles. 

Recent extension acts. Following the expiration of ISTEA in 1996, Congress 

enacted a single extension of the program. Between TEA-21 and SAFETEA-LU, 

Congress passed a then-unprecedented total of 12 short-term extension acts, 

varying in duration from two days to eight months. Between SAFETEA-LU and 

MAP-21 Congress spent almost three years (and 10 extensions) struggling to reach 

agreement on proposed program changes and to find revenue sources. Finally, 

Congress employed five extensions, covering a cumulative 14 months, to bridge 

the gap between MAP-21 and the FAST Act.

Table 1 shows the number and duration of short-term extensions to the FAHP over 

each of these reauthorization cycles.

Table 1. Extensions to authorization acts.

Expired on... Was 

extended...

For a total of about... Before enactment 

of... 

ISTEA 9/30/1996 Once 6 months TEA-21

TEA-21 9/30/2002 12 times 23 months SAFETEA-LU

SAFETEA-LU 9/30/2009 10 times 33 months MAP-21

MAP-21 9/30/2014 5 times 14 months FAST Act

Program changes. Authorization acts are the primary instruments Congress 

uses to shape and direct the FAHP—modifying existing programs, adding or 

eliminating programs, or changing program requirements.

When an authorization act establishes a program, it sets certain ground rules under 

which the program operates, such as the following:

1) The amount of funds available to the program for each fiscal year (or 

how an amount of funds available for the program is to be calculated);

2) A description of how those funds are to be distributed;

3) The length of time during which the funds may be used (termed a 

“period of availability”); and

4) A listing of eligible activities.

Each of these can be changed by subsequent acts (authorization or otherwise).
7

In a major departure from previous reauthorization acts, MAP-21 streamlined the 

complex array of existing programs into a smaller number of broader core 

programs. Hence, MAP-21’s changes fell more heavily into the “adding or 

eliminating” category. The FAST Act took a more incremental approach, largely 

maintaining MAP-21’s program structure, with a few notable changes.

The following are some examples of program changes in the FAST Act: 

Modifying an existing program. The FAST Act converted the longstanding Surface Transportation Program (STP) into the Surface 

Transportation Block Grant Program (STBG), acknowledging that this 

program has the most flexible eligibilities among all Federal-aid highway 

programs. The Act made other modifications to STBG as well, such as 

adding new eligible activities and increasing the share of the program that 

is suballocated to sub-State areas based on population. (See discussion in 

Chapter 3). The FAST Act also continued, with some program 

modifications, NHPP, the Highway Safety Improvement Program (HSIP), 

and the Congestion Mitigation and Air Quality Improvement Program 

(CMAQ).

Adding or eliminating a program. The FAST Act established a new 

National Highway Freight Program (NHFP) that provides States with 

highway-focused formula funding for use on freight-related projects.3

 It

also established a new program (known as FASTLANE), which provides 

discretionary grants for nationally-significant freight and highway 

projects.4

Modifying requirements. The FAST Act made changes related to highway 

design standards to increase flexibility and provide for greater 

accommodation of all highway users. The Act also included a range of 

provisions designed to increase innovation and improve efficiency, 

effectiveness, and accountability throughout the process of delivering 

highway projects.

Beyond changes to program features, authorization acts often contain requirements 

for studies or reports to Congress. Congress typically requires these in one of two 

situations: when it is at an impasse regarding the best solution to a problem, or 

when it lacks sufficient information to formulate a policy. Most of these studies 

and reports are completed by the departmental agencies with primary oversight 

over the areas in question.

Authorization of funding. The other major purpose of authorization acts is to 

provide funding for programs. These funds are called “authorizations,” and are the 

upper limits of funding made available to a program. The FAST Act authorized a 

total of $305 billion for fiscal years (FY) 2016 through 2020 for surface 

transportation. Of the $305 billion, $226 billion (74 percent), or an average of 

$45 billion per year, was for highway programs. 

Appendix B lists the funding amounts that the FAST Act authorized through 

FY 2020 for each Federal-aid highway program.
8

The remainder of this report explains how FHWA distributes FAHP authorizations, 

the requirements associated with their use, the controls that Congress places on 

spending, and the role of the HTF.

A surface transportation authorization proposal goes through many stages on its 

way to enactment. There is usually (but not always) an Administration (executive 

branch) proposal. Both the House and the Senate must weigh in, and the two 

chambers must resolve their differences on a compromise bill. Even then, only 

with the President’s signature—or a Congressional override of a President’s veto—

does an authorization bill become an authorization act (law).

Figure 2 shows the steps to enactment of an authorization act, and the paragraphs 

that follow provide additional detail on each step. The recycling bins shown in the 

figure reflect the many opportunities for failure along the way.

Figure 2. Enactment of an authorization act.

(Optional) Step 0: The Administration proposal. The Administration 

(executive branch) is not required by law to propose legislation to reauthorize 

highway and other surface transportation programs. However, in order to present 

its position on the future of surface transportation, the Department of 

Transportation (DOT) normally prepares such a proposal, with affected operating 

administrations participating in its development. Alternatively, the Administration 

may provide Congress with less comprehensive input, such as policy papers or 

more narrowly-targeted legislative text. Regardless of the form of the proposal, as 

required by Office of Management and Budget (OMB) Circular A-19, the draft is 

reviewed and approved by OMB and other executive agencies to ensure 

consistency with Administration policy.

A comprehensive Administration bill prepared by the DOT may be introduced in 

Congress at the request of the Administration. At least one member of Congress 

must sponsor the bill and agree to introduce it. Introducing the bill as a courtesy 

does not necessarily mean that the sponsor endorses all provisions in the proposal. 

From bill to law
9

Congress will consider the Administration bill in formulating its own legislation, 

and may incorporate entire provisions verbatim, but rarely enacts an entire 

Administration bill without change.

Committees of jurisdiction. In each of its sessions, members of Congress 

introduce a vast number of bills and resolutions that cover a wide array of subjects. 

To manage this workload, Congress is organized around committees of 

jurisdiction. These committees vary in size, and each committee’s title usually 

indicates the general scope of its jurisdiction. They conduct investigations, make 

studies, issue reports and recommendations, and review and prepare legislative 

measures on their assigned areas. Most committees also divide their work among 

several subcommittees with narrower focus and jurisdiction. This committee 

framework is designed to consolidate decision-making on broad public policy 

areas.5

Responsibility for developing surface transportation legislation rests with specific 

congressional authorizing committees, and their appropriate subcommittees. 

Consequently, legislation involving surface transportation matters can occur 

simultaneously and independently in any of a number of committees in both the 

House of Representatives and the Senate. Table 2 shows the respective committees 

of jurisdiction for each surface transportation modal administration and for the 

HTF and other revenue matters.

Table 2. Jurisdiction over surface transportation authorization.

HOUSE OF REPRESENTATIVES

Committee Jurisdiction

Committee on Transportation and Infrastructure FHWA, FTA, FMCSA, NHTSA

Committee on Ways and Means Revenue

SENATE

Committee Jurisdiction

Committee on Environment and Public Works FHWA

Committee on Commerce, Science, and Transportation FMCSA, NHTSA

Committee on Banking, Housing, and Urban Affairs FTA

Committee on Finance Revenue

In the House, the Highways and Transit Subcommittee of the Committee on 

Transportation and Infrastructure (the House T&I Committee) has primary 

jurisdiction over most aspects of the FAHP, including drafting highway authorizing 

legislation. The House T&I Committee also has jurisdiction over mass transit and 

highway safety. The HTF and other revenue matters fall under the purview of the 

House Ways and Means Committee. 

In the Senate, the Subcommittee on Transportation and Infrastructure of the 

Committee on Environment and Public Works (EPW) has jurisdiction over 

highway programs and legislation, but not over highway safety or mass transit 

issues. The Senate Commerce, Science, and Transportation Committee has 

jurisdiction over safety, while the Banking, Housing, and Urban Affairs 
10

(“Banking”) Committee has jurisdiction over mass transit concerns. Finally, the 

Senate Finance Committee has jurisdiction over the HTF and other revenue 

matters. 

Step 1: Committee hearings. Congress begins the authorization process by 

conducting hearings as a springboard for developing authorizing legislation. It 

normally holds such hearings about nine months to a year before expiration of the 

current authorization act. The purpose of these congressional hearings is to give 

interested organizations, citizens, Members of Congress, and the executive branch 

an opportunity to present their views on the future direction of Federal surface 

transportation programs, as well as for Congress to develop a record in support of 

future legislative action.

The House and the Senate work independently on their separate bills, and each 

body has its own schedule for hearings, committee meetings, and procedural votes. 

Although they may be developed concurrently, House and Senate surface 

transportation bills remain separate until brought together in conference 

committee, much later in the legislative process (see step 5, below).

Steps 2 and 3: Committee consideration. Once the hearings are complete, the 

committees begin preparation of draft surface transportation legislation, taking into 

consideration information obtained during the hearings. They may also include 

elements taken from other proposed surface transportation bills submitted during 

the current session of Congress and referred to the full authorizing committees. 

Such bills may be proposed by several groups, including the chairmen or ranking 

minority members of full authorizing committees or subcommittees, the 

Administration, or other Members of Congress who have an interest in surface 

transportation.

Member-introduced bills often concern a specific facet of the program, such as 

safety initiatives or bridges. In contrast, bills proposed by committee leadership 

are usually comprehensive, and represent an attempt to reconcile competing views 

from several sources. A committee leadership bill commonly takes on the name of 

its principal sponsor, and becomes the foundation for the committee’s draft 

legislation. It also frequently serves as the focus of additional committee hearings.

A committee considers a bill through a process known as a markup. Depending on 

a variety of factors, this markup process may begin at either the subcommittee or 

full committee level. In either case, members mark up (modify, or “amend”) the 

draft bill until a majority votes to send forward the amended version. The 

amendment process may involve voting to strike or revise existing language, or to 

add entire new sections, even to the point of preparing a completely different 

version (although this is uncommon). 

Upon completion of a subcommittee markup, the subcommittee forwards the 

revised bill to the parent full committee, which in turn holds its own markup 

session. Once approved by a majority of the full committee, the bill goes to other 

committees having jurisdiction over some aspect of the program (e.g., for Trust 

Fund matters, the House Ways and Means and Senate Finance committees would 

have jurisdiction). The bill is then “reported out” to the full chamber of its 

respective body of Congress.6

 
11

When a full committee forwards a bill to its respective full chamber, it typically 

also provides an accompanying committee report. The report expands upon the 

legislative language in the bill by providing a plain language explanation of the 

legislative text and, sometimes, an explanation for the provision. The executive 

branch and the courts use this report to help determine congressional intent. There 

are usually separate committee reports for the Senate bill and the House bill. In 

some cases, though, a committee will not submit a report to accompany its bill. 

Step 4: Floor action. The next step is for House and Senate leaders to package 

together the respective chamber’s committee-reported component bills (the Senate 

EPW Committee’s highway bill, the Senate Banking Committee’s transit bill, etc.) 

into a single, comprehensive surface transportation bill. Each chamber then moves 

its combined product to the floor for further debate and amendment, then final votes.

Step 5: Resolution of differences and final passage. Once the Senate and 

House pass their respective bills, they work to reconcile differences between the 

two bills and arrive at a mutually acceptable compromise. This reconciliation 

process takes one of two forms:

1) Amendment exchange. For a variety of reasons, the once-rare process 

of amendment exchange has become much more common in recent 

sessions of Congress. In an amendment exchange, one chamber (e.g., 

the House) takes up the other chamber’s bill, amends it, and then 

passes the amended version. If the amended version is acceptable to 

the other chamber, then that chamber passes it as well. Otherwise, the 

second chamber amends the bill further, passes that newly-amended 

bill, and returns it to the original chamber. The process continues until 

both chambers agree to sign-off on an identical bill—usually after 

substantial back-channel negotiations.

2) Conference committee. Rather than exchanging amendments, the 

House and Senate may resolve their differences through a conference 

committee. In a conference committee, members of both chambers 

meet to formally negotiate a compromise version of the two bills. 

Such a committee is usually composed of members that represent the 

relevant committees of jurisdiction. Normally, there are many 

similarities between the two bills, and the members spend the 

conference working out the differences.

Upon agreement by the conference committee, a single bill with its attendant 

report is returned to each body of Congress for final passage. Conference bills 

must be voted on in their entirety exactly as presented by the conferees; neither the 

House nor Senate may amend the bill further. 

Step 6: Presidential signature or veto. When the conference bill has passed 

both the House and Senate, it is transmitted to the President for signature. The 

President may either sign the bill into law or veto (reject) it. Only one surface 

transportation bill—the Surface Transportation and Uniform Relocation Assistance 

Act of 1987 (STURAA)—has ever been vetoed by the President.

(Optional) Step 7: Veto override. The House and the Senate may vote to override the President’s veto and enact the bill into law. A two-thirds majority vote in 

each chamber is required to override a presidential veto. Congress met this 

threshold for STURAA of 1987, overriding President Reagan’s veto of that bill.
12

Once Congress has authorized funding, the question arises of when it becomes 

available for obligation. The authority provided by Federal law to enter into 

financial obligations that will result in immediate or future outlays involving 

Federal government funds is called “budget authority.” There are two main types 

of budget authority: appropriated budget authority (ABA) and contract authority 

(CA).7

 

Figure 3 shows the procedural steps in the “lifecycles” of ABA and CA, 

highlighting the differences between the two.

Figure 3. Comparative lifecycles of appropriated budget authority and 

contract authority.

Appropriated budget authority. Most Federal programs operate using 

appropriated budget authority, which requires two acts of Congress to implement. 

The congressional passage of an authorizations act is only the initial step. The 

authorization act, in itself, does not permit the program to begin, but only 

establishes the program structure and sets an upper limit on program funding. The 

program may start (i.e., the funds may be distributed and used) only after passage 

of a second piece of legislation: the appropriations act.

In the appropriations act, Congress appropriates (makes available) the funding 

amount that can actually be used for the program. It is at this point that the 

program can proceed. Under Congress’s budgetary rules, the appropriated amount 

may be equal to, or lower than, the original amount authorized in the authorization 

act.

One example of an ABA program in the FAST Act is the Nationally Significant 

Federal Lands and Tribal Project Program. The FAST Act authorized $100 million 

for each of FY 2016-2020 for the program, but this funding is subject to 

appropriation from the General Fund. Accordingly, FHWA may only distribute 

funding for this program if Congress subsequently appropriates those funds in an 

appropriations act.

Budget authority
13

An appropriations bill may sometimes include a provision to appropriate funds for 

a program or project for which there is no supporting authorization, or in an 

amount that exceeds the original authorized funding limits. Such actions are

against the budgetary rules set by Congress and can be contested by a single 

member of Congress raising an objection (called a point of order) against the 

measure. If no member raises this sort of objection (or if Congress votes to waive 

the point of order), and Congress passes the legislation, the measure stands.

An example of this is U.S. DOT’s Transportation Investments Generating 

Economic Returns (TIGER) program, which offers capital grants for a wide range 

of surface transportation projects. Congress has never authorized the TIGER 

program within an authorization act. Nonetheless, it has appropriated a 

cumulative $5.1 billion through eight rounds of TIGER funding in appropriations

acts. These appropriations have served as the legal basis for DOT’s 

implementation of TIGER.

See Chapter 4 for additional detail on appropriations acts. 

Contract authority. Most of FHWA’s programs operate with a special type of 

budget authority called contract authority (CA). Congress has provided CA for the 

highway program for almost a century, beginning with the FY 1923 appropriations 

act for the Post Office Department.8

 Through CA, authorized amounts are 

available for obligation according to the provisions of the authorization act without 

further legislative action. The use of CA gives the States advance notice of the size 

of the Federal-aid program at the time an authorization act is enacted. This 

eliminates much of the uncertainty contained in the authorization/appropriation 

sequence that applies to ABA.

In 1974, the Congressional Budget and Impoundment Control Act of 1974 (Budget 

Act) was enacted. One of the main purposes of that act was to give Congress more 

effective control over Federal spending. As described in Chapter 4, Congress 

annually meters spending through appropriations acts. Therefore, the Budget Act

sought to reduce the number of programs that received budget authority outside the 

control of appropriations acts. To do this, the Budget Act made it “out of order” 

(against the rules of the House and the Senate) to consider a bill that would 

authorize such spending.

However, Congress also realized that there were certain programs, such as the 

FAHP, that required advance knowledge of the size of future funding commitments 

to do long-range planning and to operate smoothly from year-to-year. Thus, the 

Budget Act permits several exceptions to the standard two-step, 

authorization/appropriation process. One of these is for programs for which new 

budget authority is derived from a trust fund that receives 90 percent or more of its

receipts from user-related taxes.9

 The HTF qualified under this exception, and 

Congress continued to authorize contract authority for the FAHP.10

The law that governs the majority of Federal-aid highway programs is located in 

title 23 (the highway title) of the United States Code. A provision in that title (23 

U.S.C. 118(a)) makes all funds that are authorized from the HTF under chapter 1 

of title 23 “available for obligation on the date of their apportionment or allocation 

or on October 1 of the fiscal year for which they are authorized, whichever occurs 

first.” This provision indicates that any such funds are contract authority. And as 
14

most Federal-aid highway programs located outside of chapter 1 incorporate 23 

U.S.C. 118(a) by reference, 11 it gives those programs contract authority as well. 

(Chapter 3 of this report discusses apportionments and allocations in more detail.) 

As with other types of budget authority, CA is not cash; it is “funding” that the 

Federal government, on behalf of a State or other grant recipient, obligates 

(commits) to a given project. Once the Federal government makes an obligation, it 

is legally bound to liquidate (pay) that obligation once the bill comes due. 

However, the authorization act does not appropriate the cash to liquidate an 

obligation made under contract authority. Chapter 4 describes the piece of 

legislation that does this (the appropriations act), and Chapter 6 describes the 

process through which the HTF outlays that cash to pay States’ bills.

Title 23, United States Code. New surface transportation authorization acts 

amend title 23 of the United States Code (U.S.C.). Title 23, U.S.C., is titled 

“Highways” and includes a systematic—or “codified”—arrangement of most of 

the laws that govern the FAHP. Generally, title 23 embodies those substantive 

provisions of highway law that Congress considers to be continuing, and which 

need not be reenacted each time the FAHP is reauthorized. Each new surface 

transportation act specifies which sections of title 23 Congress wishes to repeal 

(eliminate), add, or amend.

Uncodified provisions of law. Some provisions of surface transportation law—

for example, authorization amounts or certain pilot programs—are not 

incorporated into title 23. These provisions “live” within the confines of the act 

that authorized them, but they have the same legal standing as those located in title 

23. Furthermore, highway projects and activities also must comply with 

provisions in other laws outside of title 23 (the Uniform Relocation Act, and the 

Americans with Disabilities Act, etc.).

The FAST Act included a number of uncodified provisions. Examples include the 

newly-authorized Nationally Significant Federal Lands and Tribal Projects 

Program,

12 as well as the authority for a Governor of an international land border 

State to reserve a portion of his or her State’s STBG funding for border 

infrastructure projects.13

Homes for Federal 

highway law 
15

3. Distribution of Funding

hapter 2 described the foundation for the Federal-aid Highway Program 

(FAHP): the authorization act. This chapter covers the two different ways 

in which FHWA distributes the funds authorized for the FAHP’s various 

constituent programs: apportioning funds by statutory formula and allocating

funds on some other basis. This includes a discussion of various topics that affect 

the distribution of these funds, such as penalties and set-asides.

This chapter also describes two general budget controls that apply (in selected 

circumstances) to the FAHP: rescission and sequestration. For a discussion of a 

third type of budget control, the obligation limitation, see Chapter 5.

Characteristics. Historically FHWA has referred to an “apportionment” as the

distribution of funds using a formula provided in law. An apportionment is usually 

made on the first day of the Federal fiscal year (October 1) for which the funds are 

authorized.14 At that time, FHWA makes the funds available for obligation by the 

State in accordance with Federal law.

Each year, FHWA issues an apportionment certificate for the FAHP, generally to 

the State transportation agency. The certificate officially notifies the State of the 

new funding available to it for each program. As described earlier, this funding is 

contract authority, not cash, and represents Federal budgetary resources that are 

eligible to be paid to the State. Chapter 6 describes the process through which the 

Federal government eventually pays cash to liquidate an obligation of contract 

authority.

Once FHWA makes an apportionment to a State, there are typically only two 

situations in which FHWA may withdraw the funding.15 The first is a statutory 

rescission—an action by Congress that is described later in this chapter. The 

second is if the funding lapses. Lapsing of funding is described in Chapter 4.

Overview of apportionment. For much of the life of the FAHP, Federal law set 

a formula for each apportioned program, and each State received a total Federal 

apportionment equal to the sum of its apportionments under each of these programspecific formulas. This paradigm shifted under MAP-21. MAP-21 instituted a 

one-formula process, in which FHWA:

1) Uses a formula to calculate an initial lump sum amount for each 

State’s Federal-aid apportionment; then

2) Divides the State’s lump sum among different programs based upon 

percentages defined in law.

The FAST Act maintained MAP-21’s general approach to apportionment. As 

under MAP-21, the FAST Act authorized a single combined national amount for 

each year for all the apportioned highway programs: the National Highway 

Performance Program (NHPP), Surface Transportation Block Grant Program 

C

Apportionments 
16

(STBG), Highway Safety Improvement Program (HSIP), Railway-Highway Grade 

Crossings Program (funded via a set-aside from each State's HSIP apportionment),

Congestion Mitigation and Air Quality Improvement Program (CMAQ), 

Metropolitan Planning Program, and a new National Highway Freight Program 

(NHFP). Similarly, as under MAP-21, apportioned funds account for the 

overwhelming majority (in this case, 92 percent) of all FAST Act highway funds. 

Of this combined amount, FHWA calculates the share of funding to apportion to 

each of the States. In some cases, FHWA modifies those shares slightly, based on 

States’ relative contributions to the HTF; for more on this, see the discussion of 

“Attribution to the States and the question of ‘equity’” in Chapter 7. After 

determining each State’s share, FHWA then divides that amount among the 

individual apportioned programs 

Appendix C provides additional detail on this process.

Penalties. In order to enforce certain national priorities, Congress has 

established a number of statutory penalties. If a State fails to comply with a 

required provision of law, these penalties allow, and in some cases require, the 

Secretary to take action that prevents a State from receiving or using its full 

apportionment. Potential penalties include the following:

Withholding of apportionments. Federal law requires FHWA to withhold a 

specified share of the apportionment from any State that fails to meet 

certain requirements, such as minimum drinking age, zero blood alcohol 

concentration (BAC) tolerance for minors, and commercial driver’s license 

provisions. For funds that are withheld, there may be a specific period of 

time by which the State must come into compliance before the withheld 

funds will lapse. In some cases the lapse occurs immediately. (See the 

discussion of lapsing in Chapter 4.).

Transfer of apportionments. Another type of penalty situation requires 

FHWA to transfer a portion of the noncompliant State’s apportionment to 

another program within the State. An example is the requirement to 

transfer funding from STBG to NHPP if a State fails to maintain minimum 

Interstate pavement conditions.16

Dedication of apportionments. In some cases, FHWA must set aside a 

portion of a noncompliant State’s apportionment, to be obligated only for 

the projects that will help bring the State into compliance. An example of 

this type of action is the set-aside of NHPP and STBG funds if a State is 

not in compliance with bridge and tunnel inspection standards.17 

Suspending use of apportionments or project approval. FHWA may also 

impose a penalty on funds that it has already apportioned. For example, if 

a State fails to properly maintain a project financed with Federal-aid funds, 

FHWA may freeze (refuse to allow) project approvals in that State.18

Appendix D provides a complete list of penalties associated with FHWA programs.
17

Set-asides. Federal highway law requires States to use certain sums of their 

apportionments only for special purposes.

State planning and research (SPR). Two percent of a State’s NHPP, 

STBG, HSIP, CMAQ, and NHFP funds may only be used for planning and 

research activities. One-fourth of this amount must be used for research, 

development, and technology transfer unless the State certifies that 

transportation planning expenditures will require more than 75 percent of 

the SPR amount (and the Secretary accepts the certification).19

Transportation Alternatives (TA). FHWA sets aside a portion of each 

State’s STBG apportionments to fund TA. Under MAP-21, Federal law 

and FHWA referred to this program as the “Transportation Alternatives 

Program,” or “TAP.”20

Off-system bridges. Bridges that are not located on Federal-aid highways 

are sometimes referred to as “off-system bridges”. Federal law requires 

FHWA to set aside for these bridges an amount of a State’s STBG 

apportionment equal to 15 percent of the State's fiscal year (FY) 2009 

Highway Bridge Program apportionment. FHWA may waive or reduce 

this requirement if it determines that this expenditure is unnecessary in a 

particular State. 21

In addition to these statutorily-required set-asides, the FAST Act authorizes the 

Governor of a State with an international land border, at his or her discretion, to 

reserve a specified portion of the State’s STBG funding for border infrastructure 

projects.22

Further distribution. To promote the fair and equitable use of funds and to 

meet certain priorities, States are required by law to further distribute some 

programs within the State.

Suballocation of Surface Transportation Block Grant Program funds. 

After applying the SPR and TA set-asides, FHWA is required by law to 

reserve a specified percentage of a State’s remaining STBG funds for use 

in the following areas, in proportion to the relative share each area 

constitutes of the State’s population:23

1) Urbanized areas of the State with a population greater than 

200,000 (further suballocated to each such area within a State 

based on the population of the area24); 

2) Areas of the State with a population of 5,001 to 200,000; and

3) Areas of the State with a population of 5,000 or fewer.

Under the FAST Act, this specified percentage varies by year (51 percent

in FY 2016; 52 percent in FY 2017; 53 percent in FY 2018; 54 percent in 

FY 2019; 55 percent in FY 2020).

25 The remaining STBG funds 

(including the off-system bridge set-aside) may be used anywhere in the 

State.26

Appendix E outlines the flow of funds for STBG.
18

Suballocation of Transportation Alternatives funds. After TA funds are 

apportioned to a State, the State may either use part of its TA 

apportionment to fund the Recreational Trails Program or “opt out” of the 

Recreational Trails set-aside. A State that chooses to fund Recreational 

Trails must set aside for that purpose an amount equal to its FY 2009 

Recreational Trails apportionment.27

After accounting for the Recreational Trails set-aside, FHWA reserves 

50 percent of a State’s remaining TA funds for use in the following areas, 

in proportion to the relative share each area constitutes of the State’s 

population:

1) Urbanized areas of the State with a population greater than 

200,000 further suballocated to each such area within a State 

based on the population of the area; 

2) Areas of the State with a population of 5,001 to 200,000; and

3) Areas of the State with a population of 5,000 or fewer.

The remaining 50 percent of TA funds may be used anywhere in the 

State.28

Appendix F outlines the flow of funds for TA.

Disadvantaged Business Enterprises. Unless the Secretary determines 

otherwise, not less than 10 percent of the FAST Act authorizations for 

highway, transit, and research programs must be spent with small business 

concerns owned and controlled by socially and economically 

disadvantaged individuals.29

Transferability. States may have varying needs or priorities in the use of 

Federal-aid highway program funds. In recognition of this, Federal law provides 

flexibility by permitting States to make transfers among certain apportioned 

highway programs.

Under 23 U.S.C. 126, a State may transfer up to 50 percent of its funding under 

any apportioned program to any other apportioned program, with some exceptions. 

Appendix G contains a list of transfers and exceptions.

For ease of administration, the law also allows States to request that the Secretary 

transfer funds among entities (e.g., between FHWA and the Federal Transit 

Administration, and from one State to another or to FHWA to fund one or more 

eligible projects). In these instances, the transferred funds are still used for the 

original purpose; they are just administered by a different entity.
19

The distribution of Federal-aid highway funding on any basis other than a statutory 

formula is called an allocation. FHWA may make an allocation at any time during 

the fiscal year (as compared to apportionments, which FHWA, by law, makes on 

October 1). The FHWA also retains some funding, for example, funds for the 

agency’s administrative expenses and some research activities.

In most cases, FHWA divides allocated funds among States (or other eligible 

entities) for qualifying projects based on criteria provided in law. Some 

allocations are made entirely according to provisions in the law. Others, such as 

the FASTLANE grant program,30 authorize the Secretary to make discretionary 

grant awards to eligible recipients. Because of the limited funding for these 

programs, not every State will receive an allocation in a given fiscal year. If a 

State receiving an allocation does not use it within a specified period of time, 

FHWA may withdraw the funds by administrative action and reallocate them to 

other States.

Allocated programs and funding retained by FHWA combine to account for 

approximately 8 percent of FAST Act highway funding. Appendix B lists these 

programs (and apportioned programs, as well).

Prior to MAP-21, Congress frequently directed FHWA to allocate specific amounts 

of funding to particular projects, a practice known as “earmarking.” Congress did 

this either in legislative language, or by including statements of congressional 

intent in the committee reports that accompanied the legislation. For example, in 

SAFETEA-LU, enacted in 2005, Congress directed funding to individual projects 

under programs such as High Priority Projects31 and Transportation 

Improvements.32 In more recent years, House and Senate rules have prohibited 

earmarking. As a result, neither MAP-21 nor the FAST Act contained highway 

earmarks.

Through legislation, Congress may cancel an unused balance of previously 

authorized funds. This is called a rescission: a reduction in law of budgetary 

authority before that authority would otherwise expire. For example, Congress has 

required rescissions under a number of surface transportation authorization acts.

SAFETEA-LU. When SAFETEA-LU was enacted in 2005 it included a 

provision directing FHWA to rescind $8.5 billion in States’ unobligated

highway apportionments on the last day of the Act (September 30, 2009).33 

Prior to the rescission taking effect, Congress twice modified this 

requirement through later-enacted laws,34 and FHWA ultimately rescinded 

$8.7 billion in September 2009. Notably, in March 2010 Congress 

restored the rescinded amounts through yet another law,35 and FHWA 

returned the funding to the original apportionments.

FAST Act. The FAST Act included a provision directing FHWA to rescind 

$7.6 billion in States’ unobligated highway apportionments on July 1, 

2020.

In recent years, Congress has also enacted rescissions in appropriations acts. Some 

of these rescissions have targeted particular programs or categories of programs—

for example, rescissions of prior-year earmarked funding, or of unobligated prioryear highway apportionments (similar to the rescission in SAFETEA-LU). Other 

appropriations acts have rescinded funding via across-the-board cuts. Congress 

Allocations 

Rescission 
20

uses these cuts to bring the total amount appropriated in all the appropriations acts 

for the fiscal year into line with the overall amount agreed to in the budget 

resolution, or with some other spending target. The specifics of the cuts have 

varied. 

Once funds are eliminated (by any mechanism) they cannot be obligated.

Sequestration is the cancellation of budgetary resources under a presidential order

(but based on a legal requirement). Sequestration occurs when spending exceeds a 

limit or target amount and there is an across-the-board reduction in spending. 

Congress has required sequestration under four different acts: 

Balanced Budget and Emergency Deficit Control Act of 1985 (BBEDCA). 

The BBEDCA, often called Graham-Rudman-Hollings for its Congressional 

authors, was enacted to set out a process for achieving a balanced budget by FY

1991. The BBEDCA established a maximum deficit for each of FYs 1986-1991, 

with a target of no deficit in 1991.36 At the time, it was anticipated that Congress 

would act to ensure that the deficit targets would be met each year. Nonetheless, 

BBEDCA provided for sequesters to enforce the maximum deficit target, should 

Congress fail in that regard.

Under BBEDCA, half of any necessary cuts were required to be from defense 

spending and half from domestic spending, with the cuts applied proportionally 

across the covered programs, projects, and activities.37 For FHWA, cuts applied to 

most programs, including both appropriated budget authority and contract 

authority, obligation limitation (including the limitation on general operating 

expenses), and the loan limitation for the Right-of-Way Revolving Fund. In FYs 

1986 and 1990, the Federal budget deficit targets were exceeded. In response, the 

President issued a sequester order for each of these years, reducing domestic 

spending (including highway spending) by 4.3 percent for FY 1986 and 5.3 percent 

for FY 1990. 

The Budget Enforcement Act (BEA) of 1990. The BEA amended BBEDCA, 

replacing the deficit targets with caps on Federal discretionary budget authority 

and outlays and “pay-as-you-go” requirements which required that Congressional 

actions affecting mandatory spending or revenues be at least deficit-neutral. 

Contract authority from the HTF is considered mandatory (rather than 

discretionary) spending, so Federal-aid highway contract authority was exempt 

from sequestration to enforce the discretionary caps. However, obligation 

limitations for HTF programs were subject to sequester under the caps. 

The discretionary cap was exceeded for FY 1991, requiring the President to issue a 

sequester order with an across-the-board reduction of 0.0013 percent of domestic 

discretionary accounts. That order reduced obligation limitations for the FAHP by 

approximately $200,000.

The BEA’s discretionary caps continued through FY 2002, and the pay-as-you-go 

requirements continued through FY 2006, but no further sequesters took place. In 

several instances during those periods, a sequester would have occurred under the 

discretionary limits and pay-as-you-go requirements. However, Congress 

prevented the potential sequesters through separate legislation.

Sequestration 
21

The Pay-As-You-Go (PAYGO) Act of 2010. In 2010 and 2011 Congress passed 

two laws that re-enacted budget controls. The first of these was the PAYGO Act of 

2010, which amended BBEDCA to re-establish pay-as-you-go requirements on 

legislation affecting mandatory spending and taxes, with sequestration of 

mandatory budget authority as an enforcement tool.

The PAYGO Act of 2010 exempted from its sequestration requirements a number 

of programs funded with contract authority from a trust fund, as long as the 

contract authority was subject to an obligation limitation. This exemption protects 

the vast majority of Federal-aid highway funding from sequester. However, two 

elements of the FAHP are subject to sequester under the PAYGO Act because they 

are exempt from obligation limitations: 

1) A small portion ($639 million per year) of the NHPP; and

2) The Emergency Relief (ER) Program ($100 million per year). 

Additionally, transfers to the HTF to maintain its solvency are considered 

mandatory, and are therefore also subject to sequestration under the PAYGO Act.

The Budget Control Act (BCA) of 2011. The second of the recent acts to reestablish budget controls was the BCA of 2011. The BCA re-established annual 

caps on discretionary budget authority, with sequestration of such budget authority 

if the caps are exceeded. The FAHP is funded primarily with contract authority, 

which falls on the mandatory side of the budget. However, supplemental 

appropriations from the General Fund for the ER Program (beyond the $100 

million of annual contract authority) fall on the discretionary side of the budget 

and are subject to sequester if the discretionary caps are exceeded.

Congress also included a provision in the BCA of 2011 to create the Joint Select 

Committee on Deficit Reduction, often referred to as the “Super Committee.” The 

Committee was to propose legislation to reduce the deficit by $1.5 trillion over the 

period of FY 2012 through 2021. If the Committee was unable to reach agreement 

on a proposal, or if Congress failed to enact the legislation, the BCA would impose 

a special one-time sequester in FY 2013, followed by annual sequesters in each of 

FY 2014 through 2021. Subsequent laws extended this sequester requirement 

through FY 2024. As with the PAYGO Act of 2010, these sequesters would 

exempt contract authority subject to an obligation limitation—protecting the vast 

majority of the Federal-aid highway program from sequestration. 

The Super Committee failed to reach agreement by the required deadline, 

triggering the BCA’s sequester mechanism. For FHWA this has, to date, led to the 

sequestration of the amounts indicated in Table 3. 
22

Table 3. Amounts sequestered under the Budget Control Act of 2011

FY Sequester of...

2013 • $33 million in NHPP contract authority

• $5 million in ER contract authority

• $316 million of that year’s General Fund transfer to shore up the solvency of the 

Highway Account of the HTF

• on the discretionary side of the budget, $101 million of a supplemental appropriation 

for the ER Program

2014 • $46 million in NHPP contract authority

• $7 million in ER contract authority

• $749 million of that year’s General Fund transfer to the Highway Account of the HTF

2015 • $47 million in NHPP contract authority

• $7 million in ER contract authority

2016 • $43 million in NHPP contract authority

• $7 million in ER contract authority
23

4. Obligation of Funding

t this point, FHWA has distributed Federal funds (but not cash) to the 

States as prescribed by the authorization act. This chapter discusses how 

long those funds remain available to the State and what happens if the 

State does not use the funds in a timely manner. It also describes the Federal share 

of a project’s cost and the commitment of the Federal government to pay a State 

for the Federal share of its eligible expenses. Finally, the chapter covers the 

Federal budget process and appropriations legislation. 

An obligation is a legal commitment: the Federal government’s promise to pay a 

State for the Federal share of a project’s eligible cost. This commitment occurs 

when FHWA approves the project and executes the project agreement.38 Obligated 

funds are considered “used” even though no cash is transferred. 

Obligation also is the step in the funding process under contract authority programs 

where Congress most commonly imposes budgetary controls. This usually 

involves the imposition of limitations on Federal-aid Highway Program (FAHP) 

obligations. Chapter 5 describes these limitations.

Period of availability. Funding for many Federal programs terminates at the 

end of the fiscal year for which it is appropriated. Federal-aid highway funds, in 

contrast, are typically available for obligation (use) for more than one year. When 

FHWA makes a new apportionment or allocation for an ongoing program, it adds 

that amount to the program’s unused balance from previous years. If, in an 

authorization act, Congress chooses to discontinue a program, any unused balance 

continues to be available for the period of availability that originally applied to the 

discontinued program.

Some types of funds—known as “no-year” or indefinite funds—are available until 

they are expended. However, as specified in law, under most of the major Federalaid highway programs, funds are available for obligation “...for a period of three 

years after the last day of the fiscal year for which the funds are authorized...”;39

thus, they are available for obligation for four years. For example, fiscal year (FY) 

2016 Federal-aid highway funds that FHWA apportioned on October 1, 2015, are 

available for obligation until September 30, 2019. Note that outlays (expenditures) 

associated with timely-obligated funds may occur beyond the four-year obligation 

period. 

Figure 4 shows the typical period of availability of funding for Federal-aid 

highway funding. 

A

What is an 

obligation? 

Availability 
24

Figure 4. Typical period of availability for Federal-aid highway funding.

Lapsing. If FHWA does not obligate a particular year’s funding (at the request 

of the State or other funding recipient) within the period of availability, the 

authority to obligate any remaining amount lapses—it is no longer available.40 

Since the lapse is of funding (budgetary resources), rather than cash, a State does 

not need to return any cash to the Federal government at that time; it simply has 

lost the opportunity to obligate the lapsed amount.

When obligating funds, FHWA uses a “first-in, first-out” method. This method 

assumes that the oldest funds in a given category are obligated first, minimizing 

the risk of a funding lapse. States also manage their use of FAHP funding to 

reduce the likelihood of lapsing. 

The Federal government typically does not pay for the entire cost of construction 

or improvement of Federal-aid highways. Therefore, the State or local project 

sponsor must usually “match” Federal funds with funds from other sources. The 

maximum share of an eligible project’s costs that the Federal government will 

cover is known as the Federal share. In almost all cases a State may, at its option, 

reduce the Federal share for a particular project by contributing more non-Federal 

resources than required by law.

Federal share percentages. Unless otherwise specified in the authorizing 

legislation, most projects will have an 80 percent Federal share.41 However, a 

number of statutory provisions can modify a program’s basic Federal share. 

Examples include the following:

Interstate System. The Federal share for projects on the Interstate system 

is 90 percent (unless the project adds lanes that are not high-occupancyvehicle or auxiliary lanes, in which case the Federal share will revert to the 

80 percent level).42

Sliding scale. States with large amounts of Federal lands have their 

Federal share of certain programs increased up to 95 percent in relation to 

the percentage of their total land area that is under Federal control.43

Federal share 
25

100 percent Federal funding. Certain programs, such as the Federal Lands 

Transportation Program, the Tribal Transportation Program, and the 

Territorial Highway Program, provide a 100 percent Federal share for 

projects. In other cases, programs provide full Federal funding to support 

specific types of projects, such as Emergency Relief projects (for certain 

emergency repairs made within 180 days of the event causing the need for 

such repairs),44 Highway Use Tax Evasion projects,45 and certain safety 

projects.46 The FAST Act also offered a Federal share of up to 100 percent 

for projects with innovative project delivery methods.47

Tapered Match. In some cases, FHWA may approve a “tapered” match for 

a project. Under tapered match, the Federal share may vary on individual 

progress payments on a project, as long as the total contribution of Federal 

funds does not exceed the maximum Federal share authorized for the 

project.48 These progress payments are permitted as long as a project 

agreement has been executed pursuant to 23 U.S.C. 106.49

Appendix H shows the basic Federal share for selected programs, along with 

provisions that may modify that share.

Sources of matching funds. The funds required to match Federal funding can 

come from any or all of the following sources:

1) State and/or local governments.

2) Private contributions.

3) Credit for donated private property or land lawfully obtained by the 

State or local government without the use of Federal funds.50

4) Toll revenue credits (but not for projects funded under the Emergency 

Relief program).51

5) Other Federal agencies, if specifically authorized in law. For example, 

Federal land management agencies may use their own funds for the 

non-Federal share of a project funded under title 23, United States 

Code (highways) or chapter 53 of title 49, United States Code (public 

transportation).52

6) Federal Lands Transportation Program and Tribal Transportation 

Program funds (for Federal-aid projects that provide access to or 

within Federal or tribal lands).

53

7) Recreational Trails funds (but only to match other Federal program 

funds for purposes that would be eligible under the Recreational Trails 

program).

54

8) Funds from any other Federal program (but only to fulfill the nonFederal share requirement for Recreational Trails projects, for 

purposes eligible under the program from which the funds are 

derived).

55
26

An appropriations act is a congressional action that makes funds available for 

obligation and expenditure with specific limitations as to amount, purpose, and 

duration. As described in Chapter 2, most Federal programs are funded through 

appropriated budget authority, courtesy of an appropriations act. However, as the 

FAHP operates under contract authority, the appropriations act serves a different 

function for FHWA.

Four elements of an appropriations act most significantly impact the Federal-aid 

Highway Program:

1) Appropriated budget authority (if any);

2) A limitation for the year on obligations for the Federal-aid programs 

that have contract authority;

3) A limitation for the year on FHWA’s obligation of administrative 

funding (known as the “limitation on administrative expenses,” or 

“LAE”); and

4) An appropriated amount of “liquidating cash,” which FHWA requires 

to liquidate (pay) FAHP obligations for which bills are submitted.

To become law, an appropriations bill must pass through each of the steps required 

on an authorization bill (see “From bill to law” in Chapter 2). The appropriations 

process differs from the authorization process in three substantial ways, though. 

First, an appropriations bill is an outcome of the broader Federal budget process, 

where it is preceded by the President’s Budget request and a congressional budget 

resolution. Second, an appropriations bill falls under the jurisdiction of different 

congressional committees than an authorization bill. Third, based on long-standing 

precedent, an appropriations action must originate in the House of Representatives, 

rather than the Senate. An authorization bill, in contrast, may originate in either of 

the two chambers.

As shown in figure 5, the Federal budget process has three main phases. First, the 

Administration prepares and submits to Congress the President’s Budget request.

Next, through a congressional budget resolution, the House and Senate agree on 

the total amount of Federal spending for the fiscal year. Finally, the two chambers 

develop and pass one or more appropriations bills, consistent with the constraints 

set by the budget resolution. These bills go to the President, who signs them into 

law.

Appropriations act 

Federal budget 

process
27

Figure 5. Federal budget process.

President’s Budget request. The executive branch begins the Federal budget 

process by developing the President’s Budget request. FHWA typically starts 

developing its portion of the budget in the spring, about 11⁄2 years before the 

beginning of the fiscal year being addressed. Among its contents, the FHWA 

budget includes a proposal for each of the following: 

1) Appropriated budget authority (if FHWA is requesting any);

2) An obligation limitation for the FAHP;

3) An LAE, based on FHWA’s estimate of the funding it will need to run 

the agency and oversee the FAHP; and

4) An amount of liquidating cash to be appropriated.

Chapter 5 discusses the obligation limitation. Chapter 6 describes liquidating cash 

and the projections on which the Administration relies when requesting the amount 

for a fiscal year.

Typically in June, FHWA submits its budget proposal to the Office of the Secretary 

of Transportation. The Department reviews FHWA’s budget proposal and provides 

any changes in a process known as “passback”. FHWA may appeal the passback, 

though the Department makes the final determinations. The Department then 

incorporates FHWA’s proposal, as revised via passback, into the broader 

departmental budget, then submits that budget to the Office of Management and 

Budget (OMB).

Once all of the executive agencies have developed their respective budgets and 

have the approval of OMB (including a second passback process), the budgets 

become part of the President’s Budget request. By law, the President must submit 

his or her budget request to Congress on or before the first Monday in February,

less than nine months before the fiscal year begins. The Constitution grants 

Congress the “power of the purse”—the authority and responsibility to pass laws 

that govern Federal spending—and the President’s budget is simply a proposal. 

Nonetheless, throughout the appropriations process the President will frequently 

state his or her position on the budget legislation under consideration in Congress.
28

Committees of jurisdiction. As with the authorizing process, Congress is 

divided into committees of jurisdiction for developing the budget of the United 

States, including both the Congressional budget resolution and the annual 

appropriations bills.

The House and the Senate each have a Committee on the Budget. These 

committees, established by the 1974 Congressional Budget and Impoundment 

Control Act, are charged with drawing up budget resolutions and shepherding them 

through the respective chambers. 

The House and Senate also each have a Committee on Appropriations, which is 

responsible for developing appropriations legislation. Each of these committees 

has twelve subcommittees, and each of those subcommittees produces an 

appropriations bill for its area of jurisdiction—yielding a total of 12 appropriations 

bills per year. Appropriations legislation for transportation (including FHWA) is 

under the primary jurisdiction of each chamber’s subcommittee on Transportation, 

Housing and Urban Development, and Related Agencies (THUD).

Table 4 shows the relevant committees of jurisdiction.

Table 4. Jurisdiction over the federal budget and surface transportation 

appropriations.

HOUSE OF REPRESENTATIVES

Committee Jurisdiction

Committee on the Budget Congressional Budget Resolution

Committee on Appropriations All appropriations

Subcommittee on Transportation, Housing and 

Urban Development, and Related Agencies (THUD) 

THUD appropriations

SENATE

Committee Jurisdiction

Committee on the Budget Congressional Budget Resolution

Committee on Appropriations All appropriations

THUD Subcommittee THUD appropriations

Congressional budget resolution. In the spring, Congress formulates its own 

view of the Federal budget, using the President’s budget request as input. The first 

major Congressional action is development of a Congressional budget resolution. 

Once approved, this resolution guides all congressional action when developing 

legislation for the next year. It sets high-level spending and tax levels, and 

explicitly sets a deficit or surplus level for the year. However, it does not set 

Department-level budgets—a task reserved for the follow-on appropriations bills.

After holding hearings on the President’s Budget request, the House and Senate 

Budget Committees each develop and debate a budget resolution. The resolution 

moves through the committee, then to the floor of the full chamber. As with an 

authorization bill, a budget resolution must be passed in identical form by both the 

House and the Senate. Therefore, the two bodies must resolve differences between 
29

House- and Senate-approved budget resolutions via either an exchange of 

amendments or a conference committee.

Budget resolutions are not law; they simply govern subsequent Congressional 

appropriations activity. Consequently, they do not require the President’s 

signature.

Appropriations legislation. After passing a budget resolution, the House and 

Senate develop appropriations bills. The Constitution requires the House (rather 

than the Senate) to originate “revenue bills,” which has long been interpreted as 

including appropriations bills. Accordingly, the House traditionally debates and 

passes its appropriations bills prior to the Senate, and when debating 

appropriations bills on the Senate floor, the Senate adopts the bill number (e.g., 

H.R. 1234) belonging to the corresponding House bill. As a practical matter, 

though, the Senate may begin informal development of its own bills in parallel to 

the House process.

To keep total spending consistent with the budget resolution, the Chairs of the 

House and Senate Appropriations Committees allocate that resolution’s top-line 

spending numbers among its various subcommittees. Each subcommittee drafts 

and debates a bill that sets the funding amounts for the programs under its 

jurisdiction. If approved by the subcommittee, the bill moves on to the full 

committee. The full committee then debates the bill, and if it approves it, “reports 

it out” to the full chamber of its respective body of Congress. And as with 

authorization bills, the appropriations committee typically produces a report to 

accompany its bill, providing additional direction to the executive branch on how 

to implement the law once enacted.

Each chamber debates and passes its series of twelve appropriations bills: the 

THUD bill, plus the eleven others. The House and Senate again resolve their

differences via amendment exchange or a conference committee. Once both 

chambers have approved identical versions of the THUD bill, the legislation goes 

to the President for signature.

As with any other bill, the President may sign it into law or veto. If the President 

vetoes the bill, Congress has the ability to override the veto through a 2/3 vote in 

each chamber.

In addition to the “regular” annual THUD Appropriations Act, three other types of 

appropriations actions may affect the funding available for the FAHP: a 

supplemental appropriations act, an omnibus appropriations act, and a continuing 

resolution (CR).

Supplemental appropriations act. A supplemental appropriations act is 

sometimes necessary during the course of a fiscal year when it becomes apparent 

that key operations of the Federal government require funding beyond that 

provided through the regular appropriations process. When it foresees this 

situation, the Administration will request that Congress enact supplemental 

legislation. The Emergency Relief program is, by far, the most common program 

relating to highways for which Congress has enacted supplemental appropriations.

Other 

appropriations
30

Omnibus appropriations act. In recent decades Congress has usually been 

unsuccessful in enacting the entire series of 12 appropriations bills by the 

beginning of the fiscal year. When unable to pass each individual measure, 

Congress may at times combine many—or even all—of the bills into a single, 

consolidated package known as an omnibus. The appropriations process has ended 

in an omnibus appropriations act in eight of the last ten fiscal years.

An omnibus raises different political dynamics than an individual appropriations 

bill, as it in effect presents each Member of Congress with a single vote that will 

either fund or shut down the majority of the Federal government. 

Continuing resolution. In the absence of either a regular appropriations act or 

omnibus, Congress may instead pass a CR. A CR typically extends the previous 

fiscal year’s legal authorities for a limited period of time (days, weeks, or months). 

During that period, the CR usually provides pro-rated funding, most commonly 

based on the prior year’s funding levels. 

For the Federal highway program, the continuing resolution provides the 

obligation limitation for the CR period. It also provides liquidating cash, which 

allows FHWA to liquidate State obligations (pay States) for projects that are 

underway. 
31

5. Obligation Limitation

he foregoing discussion has described the routine procedures for funding the 

Federal-Aid Highway Programs (FAHP) that have contract authority: 

authorizing legislation, distribution of funds, and obligations. Again, 

because of contract authority, the flow of these program funds is not directly 

affected by the annual appropriations process. This permits a smooth and stable 

flow of Federal-aid funds to the States, but this very benefit can be a disadvantage 

to overall Federal budgeting. A major function of the appropriations process is to 

assess the current need for, and effect of, Federal dollars on the economy. The 

appropriations process has been the traditional way to control Federal expenditures 

annually. However, the highway program, with multiple-year authorizations and 

multiple-year availability of funds, would appear to be exempt from this annual 

review. The question arises: what controls can annual Federal budget decisions 

place on the highway program?

The answer is to place a limit, or ceiling, on the total obligations that can be 

incurred for the FAHP during a year. A limitation on obligations in a given year 

does not affect the scheduled apportionment or allocation of Federal-aid highway 

funds after they are authorized. However, by controlling obligations annually, the 

program may be made more responsive to budget policy. As discussed in Chapter 

4, once an obligation is made, the Federal government must pay the State when 

bills become due. That “promise” must be kept, and so it is impossible to place 

direct controls on outlays. But by limiting the obligations, Congress may prevent 

FHWA from making the promise in the first place—eliminating the need for any 

subsequent payment.

This chapter details the history, function, and characteristics of an obligation 

limitation. It also discusses the process through which FHWA applies that 

limitation across the Federal-aid highway program. For convenience, the chapter 

uses the terms “obligation limitation” and “obligation ceiling” interchangeably.

The highway program has been subject to limitations on obligation since 1966. In 

the early years, the executive branch limited obligations. The common term for 

this action was “impoundment.” However, a turnabout came with enactment of the 

Congressional Budget and Impoundment Control Act of 1974.56 This act 

established a formal process for the executive branch and Congress to follow in 

setting limits on the use of authorized funds. 

Beginning in fiscal year (FY) 1976, Congress became the branch of government 

that places annual limitations on obligations. Each year the President’s budget 

request has recommended such a limitation for the FAHP. This recommendation is 

only a proposal to Congress for enactment. Congress will consider the 

recommendation, but may or may not actually follow it.

Congress limits FAHP obligations through a legislative act—most frequently in an 

appropriations act, since limitations are a form of budget control. Surface 

T

History 
32

transportation authorization acts also typically include obligation limitations, and 

on occasion other types of legislation, such as reconciliation bills, do as well.

The FAST Act established obligation ceilings for each of FY 2016 through 2020. 

Each year, the appropriations legislation will confirm or modify these ceilings.

The obligation ceiling limits the amount of funding that may be obligated during 

the specified fiscal year—generally without regard to the year in which the funds 

in question were apportioned or allocated. However, the FAST Act provided a few 

specific programs with multi-year obligation limitation, which may be carried over 

for several years. Some prior authorization acts also provided individual programs 

with “no-year” limitation, which is available until it is used (i.e., it does not 

expire).

A few programs within the FAHP are exempt from the obligation limitation, 

allowing FHWA to obligate funding under these programs without regard to the 

limitation on obligation. Under the FAST Act, these exempt programs included the 

Emergency Relief program, certain balances of programs exempt under prior Acts, 

and a portion ($639 million per year) of the National Highway Performance 

Program (NHPP).57

It is important to recognize that the distribution and redistribution of the individual 

State obligation ceilings do not constitute a grant or a retraction of apportioned and 

allocated sums. A State already has received apportionments or allocations as a 

result of authorizations in highway acts; the obligation limitation only governs how 

much of its unobligated balance of apportionments and allocations the State may 

obligate during a given fiscal year. Furthermore, if a State retains an unobligated 

balance of apportioned or allocated funding at the end of a fiscal year, it may carry 

over those funds for use during the following fiscal year, assuming that they have 

not lapsed.

Table 5 illustrates the degree to which an obligation limitation constrains the 

ability to obligate Federal-aid funds within a given fiscal year. As the table shows, 

the FAHP ended FY 2015 with a total of $23.3 billion in available contract 

authority. After subtracting amounts with carry-over obligation limitation from 

prior years, then adding new FY 2016 funding, the FAHP began FY 2016 with a 

total of $58.0 billion in available contract authority. The FY 2016 obligation 

limitation was $42.4 billion. Consequently, $15.6 billion was not available for 

obligation that year, due to the obligation ceiling.

Table 5. Impact of FY 2016 obligation limit on availability of funding

Note: Table does not reflect FAHP funding exempt from the obligation limitation.

$ billions

Unobligated balance (9/30/2015) 23.2

Unobligated balance with carryover limitation (no-year or multi-year) from prior years - 7.6

Unobligated balance without carryover limitation 15.6

New FY 2016 apportionments and allocations + 42.4

Total funding (without carryover limitation) available to obligate in FY 2016 58.0

FY 2016 obligation limitation - 42.4

Amount not available for obligation in FY 2016 15.6

Function and 

characteristics 
33

As with prior authorization acts, the FAST Act laid out a multi-step process that 

directs FHWA how to divide the obligation limitation among programs and the 

States. Parallel provisions in the annual Transportation, Housing and Urban 

Development, and Related Agencies (THUD) Appropriations Act typically restate 

the process without change.58 In the case of conflict, the later-enacted provision 

(usually in the appropriations act) prevails.

Under the FAST Act (and the FY 2016 THUD Appropriations Act), FHWA 

distributes the obligation limitation through the process specified below.

Appendix I also provides a step-by-step analysis of FHWA’s process for 

distributing the obligation limitation, using FY 2016 as an example. Except as 

specified below, each portion of the obligation limitation expires at the end of the 

fiscal year.

Step 1. Reserve dollar-for-dollar obligation limitation for certain programs. 

First, FHWA sets aside limitation for selected programs specified in law: 

Disadvantaged Business Enterprise (DBE) Supportive Services, On-the-Job 

Training (OJT) Supportive Services, Highway Use Tax Evasion projects, and the 

Bureau of Transportation Statistics.59 FHWA reserves limitation for each of these 

programs on a dollar-for-dollar basis—providing each program with an amount of 

obligation limitation equal to its contract authority. FHWA also reserves a 

specified amount of obligation limitation to allow the obligation of contract 

authority for the administrative expenses of both FHWA and the Appalachian 

Regional Commission (ARC). The FAST Act directed FHWA to set aside dollarfor-dollar limitation for both of these categories of administrative expenses. 

However, as described in Chapter 4, the annual appropriations act typically 

includes a specified sub-limitation on administrative expenses (LAE). This LAE 

may differ from the amount of available contract authority and overrides the 

direction to provide dollar-for-dollar limitation.

Step 2. Set aside obligation limitation for use with carryover allocated 

balances. For a variety of reasons, allocated programs are at times unable to 

obligate all of their available contract authority within a given fiscal year (e.g., FY 

2015). In such a circumstance (assuming the contract authority has not lapsed), 

they carry over the unobligated balances of contract authority into the next fiscal 

year (e.g., FY 2016). This makes the carryover balances subject to that next year’s 

obligation limitation.

To enable the obligation of prior-year allocated funds, FHWA sets aside, for each 

such program, an amount of obligation limitation equal to that program’s carryover 

contract authority balance.

Step 3. Determine ratio of remaining obligation limitation to contract 

authority. After making these initial set-asides, FHWA compares the remaining 

amount of obligation limitation to the total amount of new authorizations for the 

fiscal year for programs that are subject to the obligation limitation (and that were 

not already accounted for under the first two steps).

60 FHWA uses this ratio of 

total obligation limitation to total authorizations, known as the “limitation ratio,” in 

step four of the distribution process. 

Step 4. Set aside obligation limitation for allocated programs at the ratio. In 

step one FHWA set aside obligation limitation for use with current-year contract 

Distribution
34

authority for a few specified allocated programs: the “100 percent” programs. In 

step two, FHWA sets aside obligation limitation for use with all prior-year 

allocated contract authority. This leaves the question of how to account for 

current-year allocated funding, apart from that associated with “100 percent” 

programs.

FHWA reserves for each such program an amount of obligation limitation equal to 

the program’s new authorization for the fiscal year, multiplied by the limitation 

ratio. At the same time, FHWA “lops off” (removes) from an allocated program 

the “excess” contract authority, then distributes that lopped-off authority to States 

by formula; for additional detail, see the description of “Lop-off” below. 

The FAST Act also made obligation limitation reserved for research programs 

through this process available for four years, instead of expiring at the end of a 

single fiscal year.61

Step 5. Distribute the remaining “formula limitation” to the States. Finally, 

FHWA distributes the balance of the obligation limitation among the States based 

on each State’s relative share of total Federal-aid highway apportionments (subject 

to the limitation) for the fiscal year.62 Since FHWA distributes this obligation 

limitation by formula, it is known as “formula limitation.” 

FHWA does not provide program-specific obligation limitation for formula 

programs (e.g, there is no NHPP obligation limitation, or STBG obligation 

limitation). Rather, FHWA provides each State with a single amount of formula 

limitation that applies to all of the State’s apportioned programs, apart from those 

that are exempt from the obligation limitation, or that have carried over no-year 

obligation limitation from prior years. This offers the State the flexibility to 

determine the best combination of program funds to obligate in each category 

(NHPP, STBG, etc.) based on its individual needs, as long as its total obligations 

stay within the overall ceiling.

August redistribution. For a variety of reasons, a given program may be unable 

to obligate its share of the obligation limitation by the end of a given fiscal year. In 

recognition of this, Congress has established a statutory process to allow FHWA to 

redistribute such obligation limitation to States that can, by the year-end deadline, 

obligate more than their initial share of the ceiling. This process takes place in 

August, and consequently is referred to as August redistribution.63 Multi-year 

obligation limitation and no-year obligation limitation are not subject to August 

redistribution.

In most fiscal years, the limitation ratio that FHWA calculates above is lower than 

100 percent; i.e., the total obligation limitation (net of that set aside under steps 

one and two of the process) is less than total new authorizations of contract 

authority. In theory, this would leave each allocated program with more contract 

authority than obligation limitation, and no ability to obligate this excess contract 

authority. In practice, though, Congress has resolved this situation through a 

statutory “lop-off” process.64 Apart from a few exceptions, all allocated programs 

are subject to lop-off. The exceptions include the 100 percent programs covered 

by step one, as well as the Tribal Transportation Program, which since MAP-21 

has been statutorily exempt from the lop-off requirement. 

Lop-off
35

Under the lop-off process, FHWA removes from an allocated program any contract 

authority in excess of that program’s obligation limitation for the fiscal year. 

FHWA then combines the contract authority amounts lopped off from the various 

allocated programs and distributes the total sum among States by formula. States 

may use these funds for projects eligible under the Surface Transportation Block 

Grant Program (STBG). However, FHWA does not distribute additional obligation

limitation to accompany lopped-off contract authority. Therefore, a State must 

draw upon its formula limitation when using lop-off funds. 

As an example, in FY 2016, the FAST Act authorized $335 million in contract 

authority for the Federal Lands Transportation Program (FLTP), and the limitation 

ratio for that year was 94.9 percent. Consequently, FHWA set aside $318 million 

($335 million x 94.9 percent) in obligation limitation for FLTP and reduced the 

amount of available FY 2016 FLTP contract authority to $318 million. FHWA 

then distributed the $17 million that it had lopped off from FLTP to States for use 

on STBG-eligible projects. The States must use their formula obligation limitation 

to obligate the lop-off funding for use on STBG-eligible projects.

Appendix J lists the programs subject to lop-off under the FAST Act, as well as the 

amount that FHWA lopped off from each such program in FY 2016.

37

6. Outlay of Funding

p to this point, the discussion has focused on how the Federal-aid Highway 

Program (FAHP) is funded and shaped, how FHWA distributes the funding 

to the States, how the appropriations process affects the overall program, 

and the promise by the Federal government to pay the States for their eligible 

expenses incurred during construction of a project. This chapter discusses the 

process through which the Federal government keeps that promise: the outlay of 

cash from the Highway Trust Fund (HTF) to liquidate (pay) a prior obligation of 

Federal funding.

Four requirements must be met before the Federal government pays cash for a 

Federal-aid highway project. The first is that a State or other eligible recipient 

must submit to FHWA a voucher associated with a valid obligation of Federal-aid 

highway funding. This process is described in additional detail below (under 

“Payments to States”). The second is that the HTF must have enough cash to 

cover the amount of the voucher. The third and fourth requirements—expenditure 

authority and available liquidating cash—are described below.

Expenditure authority. The Trust Fund must have expenditure authority: the 

general legal authority, subject to an appropriations act, for the HTF to expend 

cash that it has on hand in order to meet an obligation that had been made pursuant 

to a surface transportation authorization act. Congress provides expenditure 

authority in an authorization act. This authority normally covers the period of the 

authorization act and ends on a date specified in the act; as an example, the FAST 

Act extended the authority to expend funds through September 30, 2020.

Appropriation of liquidating cash. In addition to general expenditure authority 

authorized for the HTF, FHWA must have the legal authority to outlay a specific

amount of that cash. This amount-specific authority is called a liquidating cash 

appropriation. As described in Chapter 4, each year FHWA requests liquidating 

cash in the President’s Budget request. 

Congress appropriates liquidating cash within the annual appropriations act, and 

then FHWA uses that authority to pay States. Any liquidating cash appropriated by 

Congress but not paid out by the Trust Fund during the year can be carried over for 

use in the next fiscal year. Conversely, if Congress finds that it appropriated 

insufficient liquidating cash in the annual DOT Appropriations Act to pay the Trust 

Fund’s bills, it may enact additional legislation to provide additional liquidating 

cash.65

Under the FAHP, FHWA does not distribute cash in advance to States. Instead, it 

notifies each State of the balances of Federal funds available for its use, meaning 

that the State may request obligations, begin projects, and then later be paid for 

eligible costs incurred. The project need not be completed, however, before a State 

begins to receive payments. Depending upon the type of the project, the time 

elapsing from obligation to outlay (payment) can vary from a few days to several 

U

Conditions 

precedent

Payments to 

States
38

years; see “outlay rates” below for additional detail.

Payments are normally made to States. However, if a project is initiated on a toll 

facility under the jurisdiction of a public authority in a State, payments can be 

made directly to that public authority if requested by the State transportation 

department.66

The normal sequence of events for payment to the States is as follows:

1) A contractor does work on the project.

2) The contractor sends a bill to the State, which processes the bills for all 

work done throughout the State. At this point, the State has incurred the 

cost.

3) The State sends FHWA electronic vouchers to review and approve for 

payment.

4) The FHWA certifying officer certifies the State transportation department’s 

claim for payment.

5) FHWA submits these certifications to the Treasury Department.

6) The Treasury Department transfers the Federal share of the cost for all 

projects on the vouchers directly to the State’s bank account by electronic 

funds transfer.

As figure 6 illustrates, this sequence repeats, often beginning again before the first 

round is complete. The process is routine, and it is possible that steps three 

through six may occur on the same day. 

Figure 6. Payments to States 

This general framework—obligation of funding, progression (or completion) of 

work, and only then outlay of cash—has led many to refer to the FAHP as a 

“reimbursable” program. In many States the program operates in this manner: the 

State, as the contracting agency pays the contractors’ invoices, submits the 

necessary vouchers to FHWA, and uses the Federal cash to reimburse itself. 

However, there is no legal requirement for a State to front the bill payment with 

State revenues; at its discretion, a State may instead use the Federal cash to pay the 

contractor’s Federal share of the bill. The timing of the Federal payment to the 

State is governed by an agreement between the State and the Treasury Department 

in accordance with the Cash Management Improvement Act of 1990. FHWA’s 
39

payments are generally deposited in the State’s account on the same day payments 

to the contractor are made.

The rate of outlay from the HTF varies from year-to-year. As a surface 

transportation project may take years to complete, outlays from the HTF for 

projects may similarly extend over a multi-year period. Figure 7 shows the 

number of years that pass, on average, between the obligation and outlay of 

Federal-aid highway funding. 

Figure 7. Rate of outlay of Federal-aid highway funding

Rate of outlay

41

7. The Highway Trust Fund

he previous chapters have only peripherally mentioned the Highway Trust 

Fund (HTF). This has been intentional. The HTF’s role as the source of 

liquidating cash for the Federal-Aid Highway Program (FAHP) has a 

limited impact on the financial procedures under which the highway program 

operates. However, the use of the Trust Fund provides a direct benefit to the 

highway program: it allows the program to operate with contract authority.

This chapter describes the history and operations of the HTF, its sources of 

revenue, and actions that Congress has taken in recent years to ensure that the 

Fund could pay its bills on a timely basis.

Prior to 1956, Congress funded Federal highway programs under the public 

finance principle of “spend where you must, and get the money where you can.” 

Budget authority came through the granting of contract authority, as it does now. 

Congress levied Federal taxes on motor fuels and automobile products, but the 

receipts from these taxes were not linked to funding for highways. Instead, the 

Federal government used cash from the General Fund of the Treasury to liquidate 

previously-incurred obligations for the FAHP. Otherwise, the program operated in 

terms of authorizations, obligations, appropriations, and reimbursements—much as 

it does today.

The Federal-Aid Highway Act of 1956 increased authorizations for the Federal-aid 

Primary and Secondary Systems67 and authorized significant funding of the 

Interstate System. The Highway Revenue Act of that same year established a 

budgetary mechanism—the HTF—with dedicated revenues to fund the expanded 

highway program. To support the increased authorizations, the Revenue Act 

increased some of the existing highway-related taxes and established new ones. It 

also credited most of the receipts from these taxes to the HTF, which was 

dedicated to funding Federal-aid highways.

A number of Trust Fund-related legal authorities periodically expire, including the 

imposition of the taxes that are dedicated to the HTF, the authority to place the 

receipts from those taxes into the HTF, and the authority to expend HTF revenues 

on Federal-aid highway projects. Congress exercises its spending power to 

periodically extend each of these authorities, and has done so repeatedly over the 

six decades that the Trust Fund has been in operation. The expiration date for the 

collection of user taxes is normally two years following the expiration of the 

authorization act. 

Table 6 shows the dates on which each of these authorities will expire under the 

FAST Act.

T

History and 

legal authorities
42

Table 6. Expiration dates of Highway Trust Fund-related authorities

Legal authority to... Under the FAST Act, expires on...

Impose HTF-related taxes Sept. 30, 2022 68

Transfer these receipts to the HTF Sept. 30, 2022

Expend HTF revenues on Federal-aid highway projects Sept. 30, 2020

The HTF was created as a user-supported fund: highway users would pay taxes, 

the tax receipts would flow into the HTF, and HTF balances would be dedicated 

for use on highway projects (later expanded to surface transportation projects). 

This overall construct is still in place, but the tax structure has changed since 1956. 

The HTF has three long-standing sources of income:

1) Federal fuel taxes;

2) Other Federal taxes on truck users; and

3) Interest on invested balances.

Since the latter years of SAFETEA-LU, these sources have not yielded enough 

income to fully cover the HTF’s ongoing expenses. To keep the HTF solvent, 

Congress has on a number of occasions passed legislation to transfer additional 

amounts into the HTF. These transfers are described later in this chapter.

Federal fuel taxes. Subsequent to the 1956 establishment of the HTF, a number 

of laws have increased Federal fuel taxes—most recently in 1993:

The Federal-aid Highway Act of 1959 included the first post-1956 Federal 

gas tax increase, increasing the tax from three cents per gallon to four 

cents per gallon.

The Surface Transportation Assistance Act (STAA) of 1982 and the Deficit 

Reduction Act of 1984 made major revisions to the highway taxes, 

including another increase in Federal motor-fuel taxes. The 1982 STAA 

also established a special Mass Transit Account in the HTF and directed a 

portion of the motor-fuel tax to that new account.69 The rest of the tax 

remained dedicated to the original portion of the Trust Fund, referred to as 

the “Highway Account.”

The Omnibus Budget Reconciliation Act of 1990 (OBRA 90) increased the 

Federal gasoline tax by another five cents per gallon (up to 14.1 cents per 

gallon), effective December 1, 1990. It also established a “first” for the 

HTF: half of the revenues derived from the five-cent increase went to the 

General Fund of the Treasury for deficit reduction. Before that time, 

virtually all revenues from Federal motor fuel (and other highway-related 

Federal excise taxes) had been credited entirely to the HTF.70 The General 

Fund portion of the tax was imposed on a temporary basis through 

September 30, 1995.

Sources of income
43

The Omnibus Budget Reconciliation Act of 1993 (OBRA 93) increased the 

Federal gas tax yet again, this time by 4.3 cents per gallon, effective 

October 1, 1993 (and with no expiration date). The increase brought the 

gasoline tax to 18.4 cents per gallon, and the entire amount of the increase 

was directed to the General Fund of the Treasury for deficit reduction. 

The law also permanently extended the General Fund fuel tax imposed by 

OBRA 90 and directed those revenues (except in the case of certain 

alcohol fuels) to the HTF, effective October 1, 1995.

71

In addition to increasing Federal fuel taxes, Congress has also passed laws to 

redirect certain fuel tax revenues:

The Taxpayer Relief Act of 1997 redirected the revenues from the 4.3-cents 

per gallon levied under OBRA 93 from the General Fund to the HTF, 

effective October 1, 1997. 

The Surface Transportation Extension Act of 2004, Part V (STEA 04-V) 

redirected to the Highway Trust Fund the portion of the gasohol tax that 

had continued to be deposited in the General Fund under the provisions of 

OBRA 90 and OBRA 93. This redirection was effective for the period 

October 1, 2003, through September 30, 2004.

The American Jobs Creation Act of 2004 (AJCA 04) made the STEA 04-V 

redirection permanent. It also eliminated gasohol’s partial exemption from 

the gasoline tax, which had been enacted in 1978 as an incentive to 

alternatives to petroleum fuels. In lieu of the exemption, AJCA 04 

authorized the General Fund to pay a credit to eligible filers.

Table 7 lists the rate currently in effect for each Federal fuel tax. Appendix K

shows the history of the highway fuel tax rates since the creation of the HTF.

Truck-related Federal taxes. In addition to the fuel taxes, there are three other 

Federal excise taxes that target heavy trucks to support the HTF:

1) A tax on the sale of certain new heavy-duty trucks;

2) A fee assessed annually on heavy vehicles that operate on public 

highways; and

3) A tax on certain heavy truck tires.

Table 7 lists the rate currently in effect for each of these taxes.
44

Table 7. Current Highway Trust Fund tax rates

Tax type Tax rate

Federal fuel taxes

Gasoline and gasohol 18.4 cents per gallon

Diesel 24.4 cents per gallon

Special Fuels:

General rate 18.4 cents per gallon

Liquefied petroleum gas 18.3 cents per gasoline-equivalent gallon

Liquefied natural gas 24.3 cents per gallon diesel-equivalent gallon

M85 from natural gas 9.25 cents per gallon

Compressed natural gas 18.3 cents per gasoline-equivalent gallon

Other Federal taxes on truck users

Tires: (maximum rated load capacity)

 0-3,500 pounds No Tax

 Over 3,500 pounds 9.45 cents per each 10 pounds in excess of 3,500

Truck and Trailer Sales 12 percent of retailer’s sales price for tractors and trucks 

over 33,000 pounds gross vehicle weight (GVW) and 

trailers over 26,000 pounds GVW

Heavy Vehicle Use Annual tax: Trucks 55,000 pounds and over GVW, $100 

plus $22 for each 1,000 pounds (or fraction thereof) in 

excess of 55,000 pounds (maximum tax of $550)

Proceeds from penalties and interest. The HTF also benefits from a few 

other sources of non-tax revenue, such as penalties. Since October 30, 1984, the 

proceeds from fines and penalties imposed for violation of motor carrier safety 

requirements have been deposited in the Highway Account.

72 Similarly, since 

October 22, 2004, the proceeds of certain penalties imposed by the Internal 

Revenue Code related to highway-user taxes have been deposited in the Highway 

Account.73 Effective October 1, 2015, the net proceeds of certain NHTSA motor 

vehicle safety penalties are also deposited in the Highway Account.74

In addition, the HTF collects interest on its invested balances. By law, the 

Treasury Department must invest in public debt securities any balance in the HTF 

beyond that which is needed to cover current expenses of programs funded from 

the HTF.75 From October 1, 1998, through March 17, 2010, the HTF was 

prohibited by law from receiving interest on these investments.76 However, prior 

to that period—and since March 18, 2010—the Treasury Department has invested 

HTF balances in interest-bearing securities, and has credited interest from those

securities to the Trust Fund.

Transfers to maintain solvency. Beginning in Fiscal Year (FY) 2008, and in 

each subsequent fiscal year to date, the HTF’s outlays have exceeded the revenues

it has received from the afore-mentioned sources. To ensure that the Trust Fund 

could promptly pay its bills, Congress has passed a number of laws that have 

transferred amounts from other sources into the HTF. The majority of these funds 

have come from the General Fund of the Treasury, but some originated elsewhere; 

for example, Congress has in recent years transferred some funding into the HTF 

from the Leaking Underground Storage Tank Trust Fund.
45

Table 8 lists the amounts that Congress has transferred in this manner (or in the 

case of FY 2017 and 2018, scheduled for transfer).

Table 8. Transfers to ensure Highway Trust Fund solvency 

Fiscal Year To Highway Account

($ billions)

To Mass Transit Account

($ billions)

2008 $8.0 $-

2009 7.0 -

2010 14.7 4.8

2011 - -

2012 2.4 -

2013 1/ 5.9 -

2014 1/ 18.4 4.0

2015 6.1 2

2016 52.0 18.1

2017 2/ 0.1 -

2018 2/ 0.1 -

Total $114.7 $26.9

1/ Amounts shown are net of any required sequester

2/ Scheduled for October 1, 2016, and October 1, 2017, respectively

Collection and deposit. The Federal government does not directly collect from 

the consumer most of the excise taxes credited to the HTF. Instead, these taxes are

typically paid to the Internal Revenue Service by the producer or importer of the 

taxable product; as exceptions, the tax on trucks and trailers is paid by the retailer, 

and the heavy vehicle use tax is paid by the heavy vehicle owner. As a result, most 

of the Federal fuel taxes come from a handful of States (those where major oil 

companies are headquartered) and most tire taxes are paid from Ohio (the home of 

the U.S. tire industry). Of course, all of these taxes become part of the price of the 

product, and are ultimately “paid” by the highway user.

User taxes are deposited in the General Fund of the Treasury and the amounts 

equivalent to these taxes are then transferred to the HTF. Transfers are required to 

be made at least monthly on the basis of estimates by the Secretary of the Treasury 

and later adjusted up or down on the basis of actual tax receipts.77 And as 

described earlier, amounts in the HTF are invested in public debt securities.

Attribution to the States and the question of equity. Since there is 

considerable focus on each State’s contributions to the HTF, FHWA estimates the 

amount of taxes paid by the highway users of each State. The FHWA calculates

this estimate on the basis of data reported by State motor-fuel tax agencies. 

Highway users in some States pay more in user taxes than those States receive 

back in Federal-aid highway apportionments and allocations. Such States have at 

times been referred to as “donor” States—in contrast to “donee” States that pay 

less in user taxes than they receive in Federal-aid highway apportionments and 

allocations. There has been a longstanding debate on the how to balance the 

Nation’s need for a strong, connected highway system in every State with the 

desire for an equitable return on State contributions to the HTF. In response, 

Collection of taxes
46

Congress has included in authorization acts a variety of provisions to address the 

balance.

The specific approach has varied among acts, as has the range of States that 

benefitted. For example, STAA, ISTEA, TEA-21, and SAFETEA-LU each 

authorized separate equity programs, from which FHWA apportioned funding to 

States that met statutorily-specified criteria. In contrast, neither MAP-21 nor the 

FAST Act authorized a specific equity program. Instead, they each required 

FHWA to increase the total apportionment of each State for which the 

apportionment did not meet a certain mathematical threshold, and to proportionally 

decrease the total apportionments of all other States by an equal and offsetting 

amount. The threshold for this “equity adjustment” is whether a State’s total 

apportionment equals at least 95 cents for each dollar of contributions to the 

Highway Account of the HTF that FHWA attributes to the State’s residents (based 

on the most recently-available data).78 

Table 9 describes the operations of the Highway Account in FY 2015. As the table 

shows, the Highway Account began that year with a balance of $11.4 billion. That 

year the Treasury Department made a statutorily-required transfer of $6 billion 

from the General Fund to the Highway Account. However, even after accounting 

for that transfer, the account’s outlays exceeded its income by $1.1 billion for the 

year. Furthermore, that year FHWA transferred a net total of $1.2 billion from the 

Highway Account to the Mass Transit Account. After all of this, the Highway 

Account ended the year with a balance of $9 billion. 

Table 9. Operation of the Highway Account, FY 2015

$ billions

Balance, beginning of FY 2015 11.376

Gross tax receipts 36.738

Transfers to other funds - 0.997

Interest and penalties 0.026

Transfer from General Fund 79 6.068

Net income 41.831

Outlays - 42.952

Income less outlays - 1.118

Transfers to Mass Transit Account (MTA) - 1.246

Transfers from MTA 0.029

Total impact of MTA transfers - 1.217

Balance, end of FY 2015 9.040

Transfers to other funds. Taxes on gasoline and special fuels used in

motorboats are dedicated to the Sport Fish Restoration and Boating Trust Fund80

with $1 million of that amount annually transferred to the Land and Water 

Conservation Fund. Tax receipts from gasoline used in small engines, such as 

lawnmowers and chain saws, are also dedicated to the Sport Fish Restoration and 

Boating Trust Fund. Such uses cannot be determined from the fuel tax returns 

filed by the taxpayers, which are typically oil companies. Therefore, the receipts 

are initially deposited into the HTF along with the highway fuel taxes. From there, 

the Treasury Department estimates the portion of the taxes deposited in the HTF 

Trust Fund 

operations
47

derived from such uses and transfers those tax receipts to the appropriate Trust 

Fund.81 

Taxes on aviation fuels are intended for the Airport and Airway Trust Fund 

(AATF). However, because aviation kerosene (jet fuel) can be used as a substitute 

or additive to highway diesel fuel and is taxed as a lower rate than highway diesel, 

most aviation kerosene is initially taxed as highway diesel fuel with the receipts 

deposited into the HTF. When aviation users claim their tax refunds, the Treasury 

Department charges the refunds to the HTF and transfers the remainder of the tax 

to the AATF.82 

As Table 9 indicates, transfers to other funds totaled to $997 million in FY 2015. 

The balance of the HTF has long been a point of controversy. Because of the 

nature of a “reimbursable” program like the FAHP, there may be cash in the fund 

that is not needed for immediate use. It is important to understand that this is not a 

“surplus,” or excess cash. Rather, those amounts will be needed over time to pay 

States as they submit vouchers related to prior obligations.

A comparison of the HTF operation to a personal financial situation may help 

clarify this point. Imagine a person who has a checking account balance of $500, 

has outstanding monthly bills of $1,000, and will receive another $500 in a 

paycheck at the end of the month. The current $500 balance cannot be considered 

excess, given the bills that will soon come due. However, the account also is not in 

a deficit situation, given the projected income.

The HTF operates in a similar manner. At the close of FY 2015, the Highway 

Account held a cash balance of $9 billion (see Table 10). At the same time, 

though, there were $64 billion in unpaid commitments against the HTF: 

authorizations that FHWA had previously apportioned or allocated to States (and 

other eligible recipients), but for which the Treasury Department had yet to outlay 

cash. Therefore, the $9 billion balance was not excess cash. 

The true reflection of the status of the HTF is the difference between commitments 

and income, considering in each case the full period of time over which the Trust 

Fund is authorized to operate. This difference is the amount that Congress 

considers when proposing any new commitments (additional authorizations). 

However, it is also important to remember that any such calculation is based on 

revenue projections, which can change from time to time.

During initial consideration of the HTF in the 1950s, some in Congress raised 

concerns about the ability of the new fund to sustain itself: specifically, that the 

proceeds of the taxes dedicated to the HTF might prove insufficient to make 

reimbursements when claims were made. In response to those concerns, Congress 

included in the 1956 law a provision that required the Treasury Department 

periodically to compare the HTF’s outstanding commitments against the HTF’s 

expected resources (current and future), and to reduce highway apportionments if 

necessary to keep the two in balance. This comparison is referred to as the Byrd 

Amendment, or the Byrd Test.83 The Mass Transit Account is subject to a similar, 

but separately calculated, test, known as the Rostenkowski Rule.84 Congress has 

changed the exact requirements of the Byrd Test several times over the life of the 

HTF, most recently in SAFETEA-LU.85

Significance of the 

balance

Byrd Test
48

The current version of the Byrd Test hinges on whether the HTF’s “unfunded” 

authorizations exceed the total revenues that the Treasury Department projects the 

HTF will earn over the following four year period. The Treasury Department 

calculates this quarterly, with unfunded authorizations defined as: 

• the amount of contract authority (whether obligated or unobligated)

authorized from the Highway Account, but for which the Trust Fund 

has yet to outlay cash; minus

• the current balance of the Highway Account.

If unfunded authorizations exceed projected revenues, FHWA must reduce the 

current year’s highway apportionments by an equal and offsetting amount. 86

As an example, Table 10 shows the amounts that the Treasury Department 

considered when carrying out the Byrd Test for the first quarter of FY 2016. At 

that time, Treasury determined that the Trust Fund had “passed” the Byrd Test, 

with HTF resources exceeding HTF commitments. However, if that calculation 

had shown commitments exceeding resources, FHWA would have proportionately 

reduced all FY 2016 highway apportionments. 

Table 10. Calculation of initial FY 2016 Byrd Test.

$ billions

Outstanding Highway Account authorizations not paid as of September 30, 2015 64

Less: Highway Account cash balance as of September 30,2015 - 9 

Unfunded authorizations 55

Anticipated Highway Account revenues during FYs 2017-2020 138

Over the history of the Trust Fund, the FHWA has twice reduced apportionments 

under the Byrd Test: Interstate System construction apportionments for FY 1961 

and all Highway Account apportionments for FY 2004. However, the current 

version of the Byrd Test is a less stringent method of measuring sustainability, and 

has reduced the likelihood that a reduction will be triggered.87 No Byrd Test 

reductions are anticipated for the foreseeable future.
49

Appendices
50

Appendix A. Glossary

Allocation. An administrative distribution of funds for programs that are not distributed to States by a statutory

formula.

Apportionment. The distribution of funds to States as prescribed by a statutory formula.

Appropriated Budget Authority (ABA). A form of Budget Authority that requires bothan authorization act and

an appropriations act before any funds can be obligated.

Appropriations Act. Action of a legislative body that makes funds available for expenditure with specific 

limitations as to amount, purpose, and duration. In most cases, it permits money previously authorized to be 

obligated and payments made, but for the highway program operating under contract authority, the appropriations act 

specifies amounts of funds that Congress will make available for the fiscal year to liquidate obligations. 

Authorization Act. Basic substantive legislation that establishes or continues Federal programs or agencies and 

establishes an upper limit on the amount of funds for the program(s). The current authorization act for surface 

transportation programs is the Fixing America’s Surface Transportation (FAST) Act. 

Budget Authority. Empowerment by Congress that allows Federal agencies toincur obligations that will result in 

the outlay of funds. Congress generally provides this empowerment to an agency in the form of an appropriation. 

However, for most of the highway programs, it is in the form of contract authority. 

Budget Resolution. A concurrent resolution passed by Congress presenting the Congressional Budget for each of 

the succeeding 5 years. A concurrent resolution does not require the signature of the President.

Contract Authority (CA). A form of Budget Authority that permits obligations to be made in advance of 

appropriations. Most of the programs under the Federal-Aid Highway Program operate under Contract Authority.

Expenditures. SeeOutlays. 

Federal-aid Highway Program (FAHP). An umbrella term, not defined in law, which in general refers to most

of the Federal programs providing highway funds to the States. When used in a budgetary context, FAHP specifically

refersto highway programs financed by contract authority out of the Highway Account of the Highway Trust Fund 

(HTF), plus any HTF supplemental appropriations for the Emergency Relief Program. Such authorizations are 

contained in Titles I (Federal-aid Highways) and VI (Innovation) of Division A of the FAST Act, as well as in acts

providing supplemental appropriations.

Federal Highway Administration (FHWA). The Federal agency within the U.S. Department of

Transportation that administers the Federal-aid Highway Program.

Fiscal Year (FY). The accounting period for the budget. The Federal fiscal year is from October 1 until September 

30. The fiscal year is designated by the calendar year in which it ends. For example, FY 2016 runs from October 1,

2015, through September 30, 2016.

Highway Trust Fund (HTF). An account established by law to hold Federal highway- user taxes that are 

dedicated for highway and transit related purposes. The HTF has two accounts: the Highway Account and the Mass

Transit Account. 

Obligation Authority (OA). The total amount of funds that the Federal governmentmay obligate in a year. For 

the Federal-aid Highway Program this is comprised of the obligation limitation amount plus amounts for programs

exempt from the limitation.
51

Obligation Ceiling. Identical to obligation limitation. 

Obligation Limitation. A restriction, or “ceiling” on the amount of Federal assistance that may be promised 

(obligated) during a specified time period. This is a statutory budgetary control that does not affect the 

apportionment or allocation of funds. Rather, it controls the rate at which the funds may be used. 

Obligation. The Federal government’s legal commitment (promise) to pay or reimburse the States or other entities

for the Federal share of a project’s eligible costs.

Outlays. Actual cash (or electronic transfer) payments made to the States or other entities. Outlays are provided as 

work progresses for the Federal share for approved highway programactivities.

Penalty. An action taken by Federal agencies when the grant recipient does not comply with provisions of the law.

For the highway program the imposition of penalties, which are defined in law, may prevent a State from using or 

receiving its full apportionment or may force a transfer from one program to another.

President’s Budget. A document submitted annually (due by the first Monday in February) by the President to

Congress. Itsets forth the Administration’s recommendations for the Federal budget for the upcoming fiscal year.

Rescission. Legislation enacted by Congress that cancelsthe availability of previously-enacted budget authority

before that authority would otherwise expire.

Sequestration. The cancellation of budgetary resources provided by discretionary appropriations or direct 

spending law. The concept is similar to a rescission, but this termis commonly used when discussing broad budget

controls. 

Sliding Scale. The normal Federal share of 80% for non-Interstate projects and 90% for Interstate projects is

adjusted upward to no more than 95%, based on a sliding scale, for each State with a large amount of Federal lands 

(over 5% of the total area of the State).

State. As defined in chapter 1 of Title 23, U.S.C., any of the 50 States, plus the District of Columbia and the 

Commonwealth of Puerto Rico. However, the definition of “State” varies in some specific circumstances. For 

example, highway safety programs under 23 U.S.C. define “State” to also include the Territories (the U.S. Virgin 

Islands, Guam, American Samoa, and the Northern Mariana Islands) and the Secretary of the Interior (for Indian 

Reservations). Also, Puerto Rico is not treated as a State for purpose of apportioning Federal-aid highway funds. 

Suballocation. For purposes of the FAST Act and prior transportation authorizations, the statutory reservation of a 

portion of a State’s apportioned highway funding for use in one or more specific areas within the State.

For additional definitions, see A Glossary of Terms Used in the Federal Budget Process, Government Accountability 

Office, September 2005. Also see Section 101 of Title 23, United States Code.
52

Appendix B. FAST Act Authorizations

Note: Amounts shown are authorized out of the Highway Account of the Highway Trust Fund, unless otherwise noted.

FY 2016 FY 2017 FY 2018 FY 2019 FY 2020 Total

Federal-aid Highway Program 

(Apportioned) 39,727,500,000 40,547,805,000 41,424,020,075 42,358,903,696 43,373,294,311 207,431,523,082

Estimated Split Among Programs:

National Highway Performance 

Program

22,332,260,060 22,827,910,827 23,261,963,879 23,741,388,895 24,235,621,114 116,399,144,775

Surface Transportation Block 

Grant Program

11,162,564,768 11,424,412,150 11,667,786,566 11,876,329,314 12,136,990,131 58,268,082,929

Highway Safety Improvement 

Program (HSIP) 

2,225,594,512 2,275,061,630 2,317,759,770 2,359,554,152 2,407,423,445 11,585,393,509

Railway-Highway Crossings 

Program 

225,000,000 230,000,000 235,000,000 240,000,000 245,000,000 1,175,000,000

Safety-related Programs 

(allocated set-aside from HSIP)

3,500,000 3,500,000 3,500,000 3,500,000 3,500,000 17,500,000

Congestion Mitigation and Air 

Quality Improvement Program 

2,309,059,935 2,360,308,101 2,405,187,322 2,449,216,207 2,498,960,969 12,022,732,534

Metropolitan Planning Program 329,270,722 335,938,378 342,996,446 350,360,775 358,516,037 1,717,082,358

National Highway Freight 

Program 1/

1,140,250,003 1,090,673,914 1,189,826,092 1,338,554,353 1,487,282,615 6,246,586,977

FHWA Admin. Expenses 453,000,000 459,795,000 466,691,925 473,692,304 480,797,689 2,333,976,918

General Administration/

Appalachian Regional 

Commission

429,000,000 435,795,000 442,691,925 449,692,304 456,797,689 2,213,976,918

On-the-Job Training 10,000,000 10,000,000 10,000,000 10,000,000 10,000,000 50,000,000

Disadvantaged Business 

Enterprises

10,000,000 10,000,000 10,000,000 10,000,000 10,000,000 50,000,000

Highway Use Tax Evasion 

Projects

4,000,000 4,000,000 4,000,000 4,000,000 4,000,000 20,000,000

Federal Lands & Tribal 

Transportation 1,050,000,000 1,075,000,000 1,100,000,000 1,125,000,000 1,150,000,000 5,500,000,000

Tribal Transportation 2/ 465,000,000 475,000,000 485,000,000 495,000,000 505,000,000 2,425,000,000

Federal Lands Transportation 335,000,000 345,000,000 355,000,000 365,000,000 375,000,000 1,775,000,000

Federal Lands Access 2/ 250,000,000 255,000,000 260,000,000 265,000,000 270,000,000 1,300,000,000

Other Programs 1,677,000,000 1,715,000,000 1,775,000,000 1,840,000,000 1,890,000,000 8,897,000,000

TIFIA 275,000,000 275,000,000 285,000,000 300,000,000 300,000,000 1,435,000,000

Territorial and Puerto Rico 

Highway

200,000,000 200,000,000 200,000,000 200,000,000 200,000,000 1,000,000,000

Puerto Rico Highway 

[non-add]

158,000,000 158,000,000 158,000,000 158,000,000 158,000,000 790,000,000

Territorial Highway

[non-add]

42,000,000 42,000,000 42,000,000 42,000,000 42,000,000 210,000,000

Nationally Significant Freight 

and Highway Projects

800,000,000 850,000,000 900,000,000 950,000,000 1,000,000,000 4,500,000,000
53

FY 2016 FY 2017 FY 2018 FY 2019 FY 2020 Total

Construction of Ferry Boats 3/ 80,000,000 80,000,000 80,000,000 80,000,000 80,000,000 400,000,000

Emergency Relief 100,000,000 100,000,000 100,000,000 100,000,000 100,000,000 500,000,000

Nationally Significant Federal 

Lands and Tribal Projects 

(General Fund)

100,000,000 100,000,000 100,000,000 100,000,000 100,000,000 500,000,000

Appalachian Regional 

Development Program

(General Fund)

110,000,000 110,000,000 110,000,000 110,000,000 110,000,000 550,000,000

Regional Infrastructure 

Accelerator Demonstration 

Program (General Fund)

12,000,000 0 0 0 0 12,000,000

Transportation Research 414,500,000 417,500,000 417,500,000 420,000,000 420,000,000 2,089,500,000

Highway Research and 

Development

125,000,000 125,000,000 125,000,000 125,000,000 125,000,000 625,000,000

Technology and Innovation 

Deployment

67,000,000 67,500,000 67,500,000 67,500,000 67,500,000 337,000,000

Training and Education 24,000,000 24,000,000 24,000,000 24,000,000 24,000,000 120,000,000

Intelligent Transportation Systems 100,000,000 100,000,000 100,000,000 100,000,000 100,000,000 500,000,000

University Transportation Centers 72,500,000 75,000,000 75,000,000 77,500,000 77,500,000 377,500,000

Bureau of Transportation Statistics 26,000,000 26,000,000 26,000,000 26,000,000 26,000,000 130,000,000

TOTAL CONTRACT AUTHORITY 

(Highway Account of the Highway 

Trust Fund)

43,100,000,000 44,005,100,000 44,973,212,000 46,007,596,000 47,104,092,000 225,190,000,000

TOTAL GENERAL FUND 

(Subject to Appropriation)

222,000,000 210,000,000 210,000,000 210,000,000 210,000,000 1,062,000,000

GRAND TOTAL

AUTHORIZATIONS

43,322,000,000 44,215,100,000 45,183,212,000 46,217,596,000 47,314,092,000 226,252,000,000

CONTRACT AUTHORITY EXEMPT FROM OBLIGATION LIMITATION

Emergency Relief 100,000,000 100,000,000 100,000,000 100,000,000 100,000,000 500,000,000

National Highway Performance 

Program

639,000,000 639,000,000 639,000,000 639,000,000 639,000,000 3,195,000,000

CONTRACT AUTHORITY 

SUBJECT TO OBLIGATION 

LIMITATION

42,361,000,000 43,266,100,000 44,234,212,000 45,268,596,000 46,365,092,000 221,495,000,000

OBLIGATION LIMITATION 42,361,000,000 43,266,100,000 44,234,212,000 45,268,596,000 46,365,092,000 221,495,000,000

1/ Represents net amount available after a portion is applied to the Metropolitan Planning Program per the freight formula under section 

1104(b)(6) of the FAST Act. Gross authorization for FY2016, FY2017, FY2018, FY2019, and FY2020 is $1.15 billion, $1.1billion, $1.2 billion, 

$1.35 billion, and $1.5 billion, respectively.

2/ Apportioned programs, but treated as allocated for the distribution of obligation limitation.

3/ Contains a formula, but classified as an allocated program.
54

Appendix C – Apportionment and 

Programmatic Distribution

The FAST Act authorizes a single amount for each year for all the apportioned highway programs combined. That 

amount is apportioned among the States, and then each State’s apportionment is divided among the individual 

apportioned programs. 

Total funding for Federal-aid highway formula programs 

The FAST Act authorizes a total combined amount ($39.7 billion in FY 2016, $40.5 billion in FY 2017, $41.4 

billion in FY 2018, $42.4 billion in FY 2019, and $43.4 billion in FY 2020) in contract authority to fund six 

formula programs (including certain set-asides within the programs described below):

• National Highway Performance Program (NHPP);

• Surface Transportation Block Grant Program (STBG);

• Highway Safety Improvement Program (HSIP);

• Congestion Mitigation and Air Quality Improvement Program (CMAQ);

• Metropolitan Planning; and

• The new National Highway Freight Program (NHFP).

Determination of each State’s apportionment

Reservation of supplemental STBG and NHPP funds 

Before making apportionments to States, the FAST Act requires FHWA to reserve from the total amount authorized 

for the apportioned programs: (1) for each of FY 2019 and 2020, an amount to supplement the base apportionments 

for the NHPP (“supplemental NHPP”); and (2) for each of FY 2016-2020, an amount to supplement the base 

apportionments for the STBG (“supplemental STBG”) [23 U.S.C 104(h)(1) and (2)]. The remainder, net of these 

amounts, is referred to as the “base apportionment.” [23 U.S.C 104(i)] 

Calculation of a State’s initial apportionment (in three components)

For each of these three amounts (supplemental NHPP, supplemental STBG, and base apportionment) FHWA 

determines a State’s initial apportionment, calculating for the State a share of the amount equal to the State’s share 

of FY 2015 apportionments. [23 U.S.C. 104(c)] 

Adjustment based on Trust fund contributions 

FHWA then adjusts each of the three amounts, if necessary, to ensure that the sum of the three amounts received by 

each State is at least 95% of the dollar amount of its contributions to the Highway Account of the Highway Trust 

Fund in the most recent year for which data are available. Any upward adjustment based on this comparison is 

offset by proportional decreases to the amounts of other States. [23 U.S.C 104(c)] 

Division of a State’s apportionment among programs 

After determining the three amounts for a State (supplemental NHPP, supplemental STBG, and base 

apportionment), FHWA divides the amounts among the State’s individual formula programs in the following 

manner: 
55

Step Program Calculation of amount

1 NHFP

[23 U.S.C. 104(b)(5)]

Funded in an amount equal to the national 

amount for the program: 

...multiplied by the following ratio:

FY $ billions

2016 1.15

2017 1.10

2018 1.20

2019 1.35

2020 1.50

State’s base apportionment for FY

Nat’l total base apportionment for FY

2A CMAQ

[23 U.S.C. 104(b)(4)]

Funded in an amount equal to the State’s 

base apportionment (net of step #1), 

multiplied by the following ratio: 

State’s FY09 CMAQ $

State’s total FY09 apportionments

2B Metro Planning

[23 U.S.C. 104(b)(5)(D) & 

(6)]

Funded in an amount equal to— 

• the State’s base apportionment (net of

step #1); plus

• the State’s NHFP funding (under step

#1), multiplied by the following ratio:

State’s FY09 Metro Planning $

State’s total FY09 apportionments

3 NHPP

[23 U.S.C. 104(b)(1)]

STBG

[23 U.S.C 104(b)(2)]

HSIP

[23 U.S.C. 104(b)(3)]

The remainder of the State’s base 

apportionment (net of amounts under 

steps #1 through #2B) is divided on the 

following proportions:

63.7% to NHPP

29.3% to STBG

7.0% to HSIP

...and then the NHPP and STBG amounts are increased by the “supplemental NHPP and

STBG” amounts calculated above.

4A Railway-Highway 

Crossings set-aside

[23 U.S.C. 130;

§ 126 of Division L of Pub.

L. 114-113]

Funded via a set-aside from the States’ initial 

HSIP amounts prior to apportionment— 

• based on apportionment formula under

23 U.S.C. 130; and 

• such that the national total for the

program is as follows: 

FY $ millions

2016 350 1/

2017 230

2018 235

2019 240

2020 245

4B Safety-related activities 

set-aside 2/

[§ 1519(a) of Pub. L. 112-

141, as amended by the 

FAST Act]

Funded via set-aside from the States’ initial HSIP amounts prior to apportionment— 

• determined proportionally based on the initial HSIP amounts; and

• such that the national total is $3.5 million for each fiscal year.

1/ The FAST Act set aside $225 million for FY 2016; the FY 2016 Appropriations Act increased this set-aside to $350 million. 

2/ Set-aside amount is not provided to States as apportionments, but instead funds an allocated program for safety-related activities and 

clearinghouses. Therefore, FHWA does not include it in the tables in its apportionment notice.
56

Appendix D. Penalties Applicable to the

Federal-aid Highway Program

TYPE/STATUTE REQUIREMENT

(as of the effective date of the FAST Act)

PENALTY FOR NONCOMPLIANCE

(as of the effective date of the FAST Act)

STATE TRAFFIC SAFETY LAWS

National Minimum

Drinking Age

23 U.S.C. 158

Each State must have laws that prohibit the purchase or 

public possession of any alcoholic beverage by a person who 

is less than 21 years of age.

Withholding of 8 percent of the State’s

apportionments for the National Highway

Performance Program (NHPP) and Surface

Transportation Block Grant Program (STBG). 

Funds withheld lapse immediately.

Drug Offenders

23 U.S.C. 159

Each State must certify that it either: 1) has a law that

requires the revocation or suspension of drivers' licenses for 

at least 6 months (or delay in the issuance or reissuance of a 

license) for those convicted of any violation of the Controlled 

Substances Act or any drug offense or 2) has a statement by 

the Governor opposing enactment or enforcement of such a 

law and a resolution by the State legislature expressing

opposition to such law.

Withholding of 8 percent of the State’s

apportionments for the NHPP and STBG.

Funds withheld lapse immediately.

Zero Tolerance 

Blood Alcohol 

Concentration for

Minors

23 U.S.C. 161

Each State must enact and enforce a law that considers any 

individual under 21 years who operates a motor vehicle while 

having a blood alcohol concentration (BAC) of 0.02 grams of 

alcohol per 100 milliliters of blood or above to be driving

while intoxicated or driving under the influence of alcohol.

Withholding of 8 percent of the State’s

apportionments for the NHPP and STBG.

Funds withheld lapse immediately.

Open Container

Requirements

23 U.S.C. 154

Each State must enact or have and enforce a law prohibiting 

the possession of open alcoholic beverage containers or the 

consumption of any alcoholic beverage in the passenger 

area of a motor vehicle.

For motor vehicles designed to transport many passengers, 

this requirement is considered satisfied if a State has a law 

prohibiting the possession of any open alcoholic beverage 

container by the driver (but not by a passenger): (1) in the 

passenger area of a motor vehicle designed, maintained, or 

used primarily for the transportation of persons for 

compensation; or (2) in the living quarters of a house coach 

or house trailer.

Reservation of an amount equivalent to 2.5

percent of the State’s NHPP and STBG

apportionments and associated obligation

authority. Reserved amounts will be

transferred to the State’s Section 402

apportionment for use for alcohol-impaired

driving countermeasures, for enforcement of

impaired or intoxicated driving laws, or

reserved for activities eligible under the

Highway Safety Improvement Program (HSIP),

with the amount for each purpose to be

determined by the State. The amounts

transferred to the State’s Section 402 program

or reserved for HSIP-eligible uses may be

derived from any combination of the NHPP and

STBG apportionments at the State’s option.

Use of Safety Belts

23 U.S.C. 153(h)

Each State must have a law that makes it unlawful to 

operate a passenger vehicle if any front seat occupant (other 

than a child secured in a child restraint system) is not 

properly wearing a seat belt. An alternate compliance 

criterion is provided for New Hampshire (§354, P.L. 107-87, 

Dec. 18, 2001).

Transfer of 2 percent of the State’s

apportionments for the NHPP, STBG, and

HSIP to the section 402 safety program.

Repeat Offenders

23 U.S.C. 164

Each State must enact and enforce a law that provides that 

any individual convicted of a second or subsequent offense 

for driving under the influence or while intoxicated shall:

(a) receive a suspension of all driving privileges for at least 1 

year or a restriction on driving privileges that limits the 

individual to operating only motor vehicles with an ignition 

interlock device installed for at least 1 year, unless a special 

exception applies, or a restriction on driving privileges that 

Reservation of an amount equivalent to 2.5

percent of the State’s NHPP and STBG

apportionments and associated obligation

authority. Reserved amounts will be transferred 

to the State’s Section 402 apportionment for 

use for alcohol-impaired driving 

countermeasures, for enforcement of impaired 

or intoxicated driving laws, or reserved for 

activities eligible under the HSIP, with the 
57

TYPE/STATUTE REQUIREMENT

(as of the effective date of the FAST Act)

PENALTY FOR NONCOMPLIANCE

(as of the effective date of the FAST Act)

limits the individual to operating motor vehicles only if 

participating in, and complying with, a 24-7 sobriety program 

for at least 1 year or any combination thereof;

(b) receive an assessment of the individual’s degree of 

alcohol abuse and treatment as appropriate; and

(c) receive at least an assignment of 30 days of community 

service or 5 days imprisonment (unless the State certifies 

that the general practice is that such an individual will be 

incarcerated) for a second offense and at least an 

assignment of 60 days of community service or 10 days 

imprisonment for a third or subsequent offense (unless the 

State certifies that the general practice is that such an 

individual will receive 10 days of incarceration).

(Note: The FAST Act’s changes to this requirement are 

effective as of October 1, 2016. The requirement remains as 

in effect under MAP-21 for FY 2016. )

amount for each purpose to be determined by 

the State. The amounts transferred to the 

State’s section 402 program or reserved for 

HSIP-eligible uses may be derived from any 

combination of the NHPP and STBG 

apportionments at the State’s option.

Operation of Motor 

Vehicle by 

Intoxicated Persons

23 U.S.C. 163

Each State must enact and enforce a law that provides that 

any person with a BAC of 0.08 grams of alcohol per100 

milliliters of blood or greater while operating a motor vehicle 

to be driving while intoxicated.

Withholding of an amount equivalent to 6 

percent of the State’s NHPP and STBG 

apportionments.

If a State enacts and is enforcing the 

prescribed law within 4 years from the date 

that funds were withheld, the State’s 

apportionments will be increased by an 

amount equal to the amount withheld. 

Otherwise, the withheld funds will lapse.

TRUCKS

Vehicle Weight 

Limitations—

Interstate System

23 U.S.C. 127(a)

Each State must permit a minimum and maximum of 20,000 

pound single axle, 34,000 pound tandem axle, and 80,000 

pound gross weight of combination (5-axles or more) 

vehicles to operate on the Interstate System. Maximum 

weight cannot exceed that allowable under bridge formula. 

Grandfather rights create State- specific exceptions to all

limits.

Withholding of 50 percent of State’s NHPP

apportionment. If withheld funds are not

restored during their availability period, they

will lapse.

Enforcement of 

Vehicle Size and

Weight Laws

23 U.S.C. 141(a) 

and (b)

Each State must certify that it is enforcing all State laws 

respecting maximum vehicle size and weights permitted on 

the Federal-aid primary system, the Federal-aid urban 

system, and the Federal-aid secondary system, including the 

Interstate System in accordance with 23 U.S.C. 127.

Withholding of 7 percent of the State’s

apportionments for NHPP, STBG, HSIP,

Congestion Mitigation and Air Quality

Improvement Program (CMAQ), National 

Highway Freight Program (NHFP), and

Metropolitan Planning. Withheld

apportionments are restored if enforcement is

shown to be acceptable within 1 year;

otherwise, the withheld funds are apportioned

to all other eligible States.

Registration—Proof 

of Heavy Vehicle 

Use Tax Payment

23 U.S.C. 141(c)

Each State must require proof of payment of the Federal 

heavy vehicle use tax prior to registering a heavy vehicle 

subject to the use tax.

Withholding of up to 8 percent of the State’s

apportionments for the NHPP. The withheld

funds are apportioned to other eligible States.

Commercial Driver’s 

License

49 U.S.C. 31314

Each State must be in compliance with minimum Federal 

standards for licensing, reporting, and penalties related to 

the licensing of drivers of commercial vehicles.

Withholding of up to 4 percent of the State’s

apportionments for the NHPP and STBG for

the first noncompliance and up to 8 percent

thereafter. Funds withheld lapse immediately.
58

TYPE/STATUTE REQUIREMENT

(as of the effective date of the FAST Act)

PENALTY FOR NONCOMPLIANCE

(as of the effective date of the FAST Act)

MAINTENANCE

Maintenance

23 U.S.C. 116

Each State must properly maintain or cause to be

maintained any project constructed under the provisions of 

the Federal-aid Highway Program.

After notifying the State of lack of proper 

maintenance, and a period of 90 days in which to 

remedy the issue, the Secretary shall withhold 

project approvals for all types of projects in the 

State highway district, municipality, county, and 

other subdivisions of the State in which the 

project is located, or the entire State, as the 

Secretary deems appropriate.

PLANNING, ENVIRONMENT, AND RIGHT-OF-WAY

Control of Outdoor

Advertising

23 U.S.C. 131

Each State must provide for effective control of outdoor

advertising signs along the Interstate System, on the

Primary System as it existed on June 1, 1991, and on any 

highway not on such system but on the National Highway 

System (NHS). Effective control means that a State must 

not allow outdoor advertising signs along certain routes 

unless the signs are from a permissible category.

Withholding of 10 percent of the State’s 

apportionments for NHPP, STBG, HSIP, CMAQ,

NHFP, and Metropolitan Planning. The funds 

withheld are apportioned to the other eligible 

States. The Secretary may suspend application 

of this penalty if deemed to be in the public 

interest.

Control of

Junkyards

23 U.S.C. 136

Each State must provide for effective control of the

establishment, use, and maintenance of junkyards

adjacent to the NHS.

Withholding of 7 percent of the State’s 

apportionments for NHPP, STBG, HSIP, CMAQ, 

NHFP, and Metropolitan Planning. The withheld 

funds are apportioned to other eligible States. 

The Secretary may suspend application of this 

penalty if deemed to be in the public interest.

Clean Air Act

Compliance

42 U.S.C. 7509

Each State is subject to State Implementation Plan (SIP) 

related sanctions. Each State must submit and implement 

all provisions of a complete, adequate SIP that provides 

for attainment of air quality standards in accordance with 

intermediate and final deadlines specified in the Clean Air 

Act. Penalty applies for failure to submit a SIP, or other 

related provisions, Environmental Protection Agency 

(EPA) disapproval of a SIP, and for failure to implement 

the SIP.

Cessation of certain highway project approvals 

within the non-attainment area 2 years after the 

SIP deficiencies are not corrected. Some projects 

are exempt from highway sanctions (i.e., seven 

congressionally authorized activities that 

discourage single occupancy vehicles (SOV); 

safety projects whose principal purpose is to 

improve safety by significantly reducing or 

avoiding accidents; and projects which EPA finds 

will improve air quality and not encourage SOV).

Transportation

Conformity

42 U.S.C. 7506(c)

No transportation plan, program, or project may be

approved, accepted, or funded unless it has been found to 

conform to an applicable SIP by the metropolitan planning 

organization and the DOT. The Clean Air Act requires 

USDOT to make a conformity finding on the metropolitan 

transportation plan and TIP and a project level conformity 

finding on FHWA/FTA projects within a nonattainment or 

maintenance area, based on technical analysis using

transportation, emissions, and air quality models.

Lack of a conformity determination (a conformity 

lapse) on an area's transportation plan or 

transportation improvement program (TIP) will 

prevent the expenditure of FHWA and FTA funds 

on many activities, with the exception of certain 

exempt categories. The consequences of a 

conformity lapse would apply to the entire 

nonattainment or maintenance area.

Metropolitan

Planning

23 U.S.C. 134(k)(5)

Each metropolitan planning organization (MPO) in a

transportation management area must be certified at least 

every 4 years by the Secretary of Transportation to be 

carrying out the required planning process in accordance 

with applicable provisions of Federal law.

The Secretary may withhold up to 20 percent of 

the State’s apportionments attributable to the 

metropolitan planning area of the MPO for 

projects funded under Title 23 and Chapter 53 of 

Title 49, U.S.C. Funds are restored when the 

Secretary certifies the MPO.
59

TYPE/STATUTE REQUIREMENT

(as of the effective date of the FAST Act)

PENALTY FOR NONCOMPLIANCE

(as of the effective date of the FAST Act)

PERFORMANCE AND ACCOUNTABILITY

Interstate System

Pavement Minimum

Condition

23 U.S.C. 119(f)(1)

Interstate pavement condition, excluding bridges on the

Interstate system, in each State must meet or exceed the 

minimum level of condition established by the Secretary by

regulation.

If a State reports that Interstate pavement 

conditions (not including on Interstate bridges) 

falls below the minimum, the State must, at a 

minimum, devote the following resources to 

improve Interstate pavement conditions during 

the following fiscal year (and each year thereafter 

if the condition does not exceed the minimum):

(1) NHPP funds in an amount not less than the 

State’s FY 2009 Interstate Maintenance (IM) 

apportionment, to increase by 2% per year for 

each year after FY 2013; and

(2) funds transferred from STBG (other than 

suballocated amounts) to NHPP in an amount 

equal to 10% of the State’s FY 2009 IM 

apportionment.

NHS Bridge 

Minimum Condition

23 U.S.C. 119(f)(2)

Not more than 10 percent of the NHS bridge deck area in 

each State may be on structurally deficient bridges.

Set-aside from the State’s NHPP funds of an 

amount equal to 50 percent of the State's

Highway Bridge Program apportionment in FY 

2009; set-aside amount to be used only for 

eligible projects on NHS bridges.

NHPP Target

Achievement

23 U.S.C. 119(e)(7)

Each State must achieve or make significant progress 

toward achieving its performance targets for the

performance measures established by DOT for the NHS.

If a State fails to achieve or make significant 

progress toward these targets, it must describe in 

its next performance report to DOT the actions it 

will undertake to achieve its targets.

Rural Road Safety

23 U.S.C. 148(g)(1)

Each State must maintain or improve the fatality rate on 

rural roads.

If the traffic fatality rate on rural roads in a State 

increases over the most recent two-year period 

for which data are available, in the next fiscal 

year the State must obligate for projects on high 

risk rural roads an amount equal to at least 200 

percent of the amount of funds that the State 

received for high risk rural roads in FY 2009.

Older Driver Safety

23 U.S.C. 148(g)(2)

Each State must maintain or improve the number of

fatalities and serious injuries per capita for drivers and 

pedestrians over the age of 65

If the number of traffic fatalities and serious 

injuries per capita for drivers and pedestrians 

over 65 in a State increases during the most 

recent two-year period for which data are 

available, the State must include, in the 

subsequent Strategic Highway Safety Plan of the 

State, strategies to address the increases in 

those rates, taking into account the 

recommendations in the FHWA’s Highway 

Design Handbook for Older Drivers and 

Pedestrians.

HSIP Target

Achievement

23 U.S.C. 148(i)

Each State must achieve or make significant progress

toward achieving its performance targets for the 

performance measures established by DOT for the HSIP.

If a State fails to achieve or make significant 

progress toward these targets it must: 1) annually 

submit an implementation plan as described 

under the HSIP; and 2) use a portion of its 

obligation authority only for HSIP projects. The 

dedicated amount must be equal to the State’s 

apportionment for the HSIP program in the prior 

year. The requirements continue until the 

Secretary determines that the State is meeting its 

targets or making significant progress.
60

Appendix E. Sub-State Distribution of Surface 

Transportation Block Grant Program Funding
61

Appendix F. Sub-State Distribution of 

Transportation Alternatives Funding
62

Appendix G. Transferability of Apportioned 

Funding

This appendix describes options to transfer funds from one apportioned highway program to another. Other transfer options exist, including

transfers of funds to from one State to another, from a State to Federal agency, or among certain projects designated in statute. Guidance

on the full range of transfer options, as well as procedures for executing transfers, is issued by the Federal Highway Administration’s Office of

the Chief Financial Officer.

Program Transferability Provisions Statute

National Highway 

Performance 

Program (NHPP)

A State may transfer up to 50% of its NHPP apportionment to its STBG, NHFP, 

HSIP, CMAQ, and/or TA apportionments.

23 U.S.C. 126(a)

Surface 

Transportation Block 

Grant Program 

(STBG)

A State may transfer up to 50% of its STBG apportionment to its NHPP, NHFP, 

HSIP, and/or CMAQ apportionments. The amount transferred may not come from 

the portion of STBG that is required to be suballocated to sub-State areas.

23 U.S.C. 126(a) and 126(b)(1)

Highway Safety 

Improvement 

Program (HSIP)

A State may transfer up to 50% of its HSIP apportionment to its NHPP, NHFP, 

STBG, CMAQ, and/or TA apportionments.

23 U.S.C. 126(a)

Congestion 

Mitigation and Air 

Quality Improvement 

Program (CMAQ)

A State may transfer up to 50% of its CMAQ apportionment to its NHPP, NHFP, 

STBG, HSIP, and/or TA apportionments.

23 U.S.C. 126(a)

Metropolitan 

Planning

A State may not transfer its Metropolitan Planning apportionment to other highway 

program apportionments.

23 U.S.C. 126(b)(1)

National Highway 

Freight Program 

(NHFP)

A State may transfer up to 50% of its NHFP apportionment to its NHPP, STBG, 

HSIP, CMAQ, and/or TA apportionments.

23 U.S.C. 126(a)

Transportation 

Alternatives (TA)

A State may transfer up to 50% of its TA funds to its NHPP, NHFP, STBG, HSIP, 

and/or CMAQ apportionments. The amount transferred must come from the portion 

of TA funds that is available for use anywhere in the State (no transfers of 

suballocated TA funds or TA funds reserved for the Recreational Trails Program). 

23 U.S.C. 126(a) and 126(b)(2)

Rail-Highway 

Crossings Program

A State may transfer up to 100% of its Rail-Highway Crossings apportionment to its 

HSIP apportionment if the State demonstrates to the satisfaction of the Secretary that 

it has met all its needs for installation of protective devices at railway-highway 

crossings.

23 U.S.C. 130(e)(2)
63

Appendix H. Federal Share

The maximum share of project costs that may be funded with Federal-aid highway funds (the “Federal share”) varies based upon the Federalaid program from which the project receives funding. In some cases this share is also adjusted based on related statutory provisions. The 

FAST Act made relatively few changes to Federal share; those changes are shown in boldface below.

“Standard” Federal share

23 U.S.C. 120 provides that except as otherwise provided, the Federal share payable shall be— 

• 90% for a project on the Interstate System (including a project to add high occupancy vehicle lanes or auxiliary lanes but excluding a

project to add other lanes); and

• 80% for any other project.

There are a number of exceptions and adjustments to the “standard” Federal share. See below (and program-specific fact sheets) for 

information about, and the applicability of, these exceptions and adjustments.

Adjustments to Federal share

Sliding scale

23 U.S.C. 120(a) and (b) authorize an upward adjustment (the “sliding scale”) to the Federal share for a State containing Federal and 

nontaxable Indian lands. A sliding scale State is eligible for an increased Federal share based upon the location of the project—90-95% for an 

applicable Interstate project and 80-95% for any other project. The amount of the upward adjustment is based on the percentage of Federal and 

nontaxable Indian lands in the State. 

Other adjustments to Federal share

• Designated types of projects. Certain specified types of projects, mostly targeting safety improvements, are eligible to receive a

Federal share of 100%. A State may apply this increased Federal share on no more than 10% of its combined apportionment under

23 U.S.C. 104. [ 23 U.S.C. 120(c)(1)]

• Innovative project delivery methods. A project incorporating innovations described in 23 U.S.C. 120(c)(3) is eligible for an increased

Federal share of up to 100% if funded by the National Highway Performance Program (NHPP), Surface Transportation Block Grant

(STBG) Program, or Metropolitan Planning program. The FAST Act added specific mention of innovative engineering or design

approaches and project delivery methods as activities eligible for this increased Federal share. [FAST Act §1408(a)]

• Workforce development. Subject to project approval by the Secretary, a State may obligate NHPP, STBG, Highway Safety

Improvement Program (HSIP), and Congestion Mitigation and Air Quality Improvement Program (CMAQ) funds for surface

transportation workforce development, training, and education at a Federal share of 100%. Activities under the Local Technical

Assistance Program limited to a Federal share of 50%. [23 U.S.C. 504(e)]

• Appalachian Development Highway System (AHDS) projects. For fiscal years 2012 through 2050 (previously through 2021), a

State that uses apportioned funding to construct a highway or access road on the ADHS is eligible for a Federal share of up to 100%

on that project. [FAST Act § 1435]

• Projects within Indian reservations, national parks and monuments. When an eligible project uses funds from a program apportioned

under 23 U.S.C. 104 and that project is located within the boundaries of an Indian reservation, national park, or national monument,

the Federal share may be 100%. [23 U.S.C. 120(f)]

• Toll projects. A toll project under 23 U.S.C. 129 is eligible for a maximum Federal share of 80% (regardless of whether the project

would have qualified for a higher Federal share if advanced as a non-toll facility). [23 U.S.C. 129(a)(5)]

• [Repealed] Projects to improve freight movement. Section 1116 of MAP-21 authorized an increased Federal share for certain

projects that demonstrably improved freight movement. However, the FAST Act repealed this provision. [FAST Act § 1116(c)]

Increased non-Federal share

23 U.S.C. 120(h) authorizes a State to contribute an amount in excess of the non-Federal share of any project under title 23 U.S.C., thus 

decreasing the Federal share for the project.

Transfers of funding between FHWA and FTA

Federal-aid highway funds made available for a transit project or transportation planning may be transferred to the Federal Transit 

Administration (FTA) and administered in accordance with FTA’s requirements (under chapter 53 of title 49). Similarly, Federal transit funding 

made available for a highway project or transportation planning may be transferred to FHWA and administered in accordance with title 23 

requirements. In either case, the transferred funds remain subject to the Federal share that applied to the category from which the funding was 

derived. [23 U.S.C. 104(f)]
64

Program

Federal 

share

(%) 1

Plus eligible for...

Sliding 

scale 2

100% for 

designated 

types of 

projects 3

Up to 100%

for 

innovative

delivery 

methods 4

100% for 

workforce 

development 5

Up to 

100% for 

ADHS 

projects 6

100% within 

Indian 

reservations, 

national 

parks, and 

monuments7

National Highway Performance 

Program

80 / 90 8,9      

Surface Transportation Block 

Grant Program

80 / 90 8      

Highway Safety Improvement 

Program

90 8,10    

Railway-Highway Crossings 90 11

Congestion Mitigation & Air 

Quality Improvement Program

80 / 90 8    

National Highway Freight 

Program

80 / 90 8    

Metropolitan Planning 80 8  

State Planning and Research 80 12

Transportation Alternatives 80 / 90 8   

Recreational Trails Program 80 13 

Tribal Transportation Program 100 14

Federal Lands Transportation 

Program

100 14

Federal Lands Access Program 80 / 90 8,15  

Nationally Significant Federal 

Lands and Tribal Projects 

Program

Up to 90 16

Puerto Rico Highway Program 80 / 90 8  

Territorial Highway Program (or 

any project in the specified 

territories)

100 17

Emergency Relief 80-100 18 

Emergency Relief for Federally 

Owned Roads

100 19

Construction of Ferry Boats & 

Ferry Terminal Facilities

80 20

Highway Research & 

Development Program

80 21

Technology & Innovation 

Deployment Program

80 21

Training & Education 80 21, 22

Intelligent Transportation 

Systems Program

80 21

Advanced Transportation & 

Congestion Management 

Technologies Deployment

Up to 50 23

Surface Transportation System 

Funding Alternatives

Up to 50 24

Nationally Significant Freight 

and Highway Projects

60/80/100 25
65

 

1

 The Federal share specified in this column may be subject (as specified) to one or more of the provisions referenced in the subsequent 

columns. In some circumstances the Federal share may also be modified by the provisions described above related to projects requiring 

Federal toll authority. 

2

 23 U.S.C. 120(a)-(b). 

3

 23 U.S.C. 120(c)(1). 

4 23 U.S.C. 120(c)(3), as amended by FAST Act § 1408(a).

5

 23 U.S.C. 504(e). 

6 MAP-21 § 1528(c), as amended by FAST Act § 1435. Increased Federal share applies through FY 2050. 

7

 23 U.S.C. 120(f). 

8

 “Standard Federal share” of 90% for a project on the Interstate System (including a project to add high occupancy vehicle lanes or auxiliary 

lanes but excluding a project to add other lanes) and 80% for any other project or activity. [23 U.S.C. 120(a)-(b)] 

9

 With respect to the second fiscal year beginning after the date of establishment of the process for State development of an asset management 

plan as required by 23 U.S.C. 119(e)(8), the NHPP Federal share for a State that has not developed and implemented an asset management 

plan will be reduced to 65% until it develops and implements its plan. [23 U.S.C. 119(e)(5)] 

10 23 U.S.C. 148(j). 

11 23 U.S.C. 130(f)(3). 

12 The Secretary may increase this share (up to 100%) if he or she determines that this would best serve the interests of the Federal-aid highway 

program. [ 23 U.S.C. 505(d)] 

13 23 U.S.C. 206(f) (which cites to 23 U.S.C. 120(b), with some specified exceptions). 

14 23 U.S.C. 201(b)(7)(A). 

15 23 U.S.C. 201(b)(7)(B). 

16 FAST Act §1123(g). Federal funds other than those made available under titles 23 or 49 U.S.C. may be used for the non-Federal 

share.

17 23 U.S.C. 120(g). 

18 Emergency Relief (ER) funds are typically subject to the standard Federal share: 80%, with 90% on Interstates, in both cases subject to the 

sliding scale. However, this share may be adjusted as follows: 

 Up to 100% for eligible emergency repairs within 180 days of the disaster or catastrophic failure. The Secretary may extend this time 

period, taking into consideration any delay in the ability of the State to access damaged facilities to evaluate damage and the cost of repair. 

[23 U.S.C. 120(e)(1) & (3)] 

 Up to 90% for eligible permanent repairs to restore facilities to pre-disaster condition if the State’s ER-eligible expenses for the FY exceed 

the State’s combined NHPP/STP/HSIP/CMAQ/NHFP/Metropolitan Planning apportionment for that FY. [23 U.S.C. 120(e)(4)] 

19 23 U.S.C. 120(e)(2) as amended by FAST Act § 1408(b). Prior to the amendment, eligible Federal Lands Access Transportation 

Facilities qualified for a Federal share of 100%. Per § 421 of the Department of Transportation Appropriations Act, 2016 (P.L. 114-113 , 

the FAST Act amendment applies to projects to repair or reconstruct facilities damaged as a result of a qualifying natural disaster or 

catastrophic failure that occurs after October 1, 2015.

20 23 U.S.C. 147(b). 

21 Except as expressly provided by the FAST Act or otherwise determined by the Secretary, projects and activities funded under Title VI 

(Innovation) of the FAST Act are subject to a Federal share of 80%. [FAST Act § 6002(c)]. The Federal share of activities carried out under a 

cooperative research and development agreement entered into under chapter 5 of 23 U.S.C. shall not exceed 80%, except that the Secretary 

may approve a greater Federal share if there is substantial public interest or benefit. [23 U.S.C. 502(c)(3)] 

22 This share is reduced to 50% for activities carried out by a local technical assistance center and increased to 100% for activities carried out by 

a tribal technical assistance center. [23 U.S.C. 504(b)(3)]

23 FAST Act §6004, 23 U.S.C. 503(c)(4)(J). 

24 FAST Act §6020(g).

25 The standard Federal share is up to 60%, but Federal assistance from other sources may increase this to 80%. Federal funds from

sources other than 23 U.S.C. or 49 U.S.C. may be used to pay the non-Federal share of the cost of a project carried out under this 

program by a Federal land management agency. [FAST Act §1105, 23 U.S.C. 117(j)] 
66

Appendix I. Distribution of the FY 2016 

obligation limitation

This appendix describes the manner in which FHWA distributed the FY 2016 obligation limitation, pursuant to section 120 of the Department of 

Transportation Appropriations Act, 2016 (Title I of Division L Public Law 114-113). All section references shown are to Division L of Public Law 

114-113. 

New FY 2016 New FY 2016

Contract Obligation

Authority Limitation

FY 2016 Total 43,100,000,000 42,361,000,000 

Beginning: Sec. 120(b)

Exclude 

Exempt

Programs

Exempt Programs:

Emergency Relief 100,000,000 ---------- 

National Highway Performance Program (portion) 639,000,000 ---------- 

739,000,000 ---------- 

Total Subject to Limitation 42,361,000,000 42,361,000,000 

STEP 1: Sec. 120(a)(1)

Set aside

certain 

programs

at 100%

100% Accounts:

FHWA Administration (net of set-asides) 429,000,000 425,752,000 

 ARC Administrative Expenses (set-aside) ---------- 3,248,000 

 DBE Supportive Services (set-aside) 10,000,000 10,000,000 

 OJT Supportive Services (set-aside) 10,000,000 10,000,000 

 Highway Use Tax Evasion Projects (set-aside) 4,000,000 4,000,000 

Bureau of Transportation Statistics 26,000,000 26,000,000 

Subtotal, 100% Programs 479,000,000 479,000,000 

STEP 2: Sec. 120(a)(2)

Set aside

limitation for 

carryover

Carryover, Allocated Programs ---------- 2,132,225,485 

STEP 3: Sec. 120(a)(3)

Determine

ratio of 

obligation

limitation to 

contract 

authority

Subtotal to Determine Ratio 41,882,000,000 39,749,774,515 

(Balances remaining after set-asides in Steps 1 & 2)

Ratio 94.9090% 94.9%

STEP 4: Sec. 120(a)(4)

Set aside

limitation

for allocated 

pgms.

based on ratio

Tribal Transportation Program (no lop-off) 465,000,000 441,285,000 

Other Allocated Programs (net of penalties) 2,322,316,160 2,203,878,036 

Puerto Rico Penalties (immediate lapse) 9,683,840 ---------- 

STEP 5: Sec. 120(a)(5)

Distribute 

remaining

limitation to the

States

Distributed to the States 39,085,000,000 37,104,611,479 

(before transfer penalties and high risk rural road set-aside) 94.9331%
67

Appendix J. Lop-off from allocated programs

FY 2016 ALLOCATED PROGRAMS

Application of Sec. 120(e) of P.L. 114-113 - "Lop-off" Provision

FY 2016 Less; Net 94.9% 5.1%

Authorization Penalties Authorization After "Lop Off" Reduction 

Federal Lands Transportation 

Program

335,000,000 335,000,000 317,915,000 17,085,000 

Federal Lands Access 

Program

250,000,000 250,000,000 237,250,000 12,750,000 

Transportation Infrastructure 

Finance and Innovation 

Program

275,000,000 275,000,000 260,975,000 14,025,000 

Puerto Rico Highway Program 158,000,000 9,683,840 1/ 148,316,160 140,752,036 7,564,124 

Territorial Highway Program 42,000,000 42,000,000 39,858,000 2,142,000 

Construction of Ferry Boats 

and Ferry Terminal Facilities

80,000,000 80,000,000 75,920,000 4,080,000 

Nationally Significant Freight 

and Highway Projects

800,000,000 800,000,000 759,200,000 40,800,000 

Safety-related Programs

(HSIP set-aside) 2/

3,500,000 3,500,000 3,321,500 178,500 

Highway Research and 

Development Program 3/

125,000,000 125,000,000 118,625,000 6,375,000 

Technology and Innovation 

Deployment Program 3/

67,000,000 67,000,000 63,583,000 3,417,000 

Training and Education 3/ 24,000,000 24,000,000 22,776,000 1,224,000 

Intelligent Transportation 

Systems 3/

100,000,000 

100,000,000 

94,900,000 5,100,000 

University Transportation 

Centers 3/

72,500,000 

72,500,000 

68,802,500 3,697,500 

TOTAL 2,332,000,000 9,683,840 2,322,316,160 2,203,878,036 118,438,124 

1/ $9,683,840 is withheld from Puerto Rico Highway Program pursuant to section 158 of 23 U.S.C., related to minimum drinking age. Funds so 

withheld immediately lapse.

2/ Set-aside from the Highway Safety Improvement Program for Operation Lifesaver, work zone safety grants, guard rail safety training, work 

zone safety clearinghouse, and public road safety clearinghouse.

3/ This program receives obligation limitation that is available for four fiscal years.
68

Appendix K. Historical Federal Fuel Tax Rates

The table below lists Federal excise tax rates on highway motor fuel from 1956-present. Except as specified, tax rates are shown in cents/gallon.

Tax 

Rate

Effective 

Date

Distribution Of Tax

Source of Change

Highway Trust Fund Leaking 

Underground 

Storage Tank 

Trust Fund

General Fund For:

Highway 

Account

Mass 

Transit 

Account

Deficit 

Reduction

Not 

Specified

GASOLINE

3 07/01/1956 3 - - - - Highway Revenue Act of 1956 P.L. 84-627

4 10/01/1959 4 - - - - Federal-Aid Highway Act of 1959 P.L. 86-342

9 1/ 04/01/1983 8 1 - - - Surface Transportation Assistance Act of 1982 P.L. 97-424

9 1/ 08/01/1984 8 1 - - - Deficit Reduction Act of 1984 P.L. 98-369

9.1 01/01/1987 8 1 0.1 - - Superfund Amendments and Reauthorization Act of 1986 

P.L. 99-499

14.1 12/01/1990 10 1.5 0.1 2.5 - Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

18.4 10/01/1993 10 1.5 0.1 6.8 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

18.4 10/01/1995 12 2 0.1 4.3 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

18.3 01/01/1996 12 2 - 4.3 - Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

18.4 10/01/1997 15.45 2.85 0.1 - - Taxpayer Relief Act of 1997 P.L. 105-34

18.4 2/ 10/01/1997 15.44 2.86 0.1 - - Transportation Equity Act for the 21st Century P.L. 105-178

DIESEL FUEL

3 07/01/1956 3 - - - - Highway Revenue Act of 1956 P.L. 84-627

4 10/01/1959 4 - - - - Federal-Aid Highway Act of 1959 P.L. 86-342

9 1/ 04/01/1983 8 1 - - - Surface Transportation Assistance Act of 1982 P.L. 97-424

15 1/ 08/01/1984 14 1 - - - Deficit Reduction Act of 1984 P.L. 98-369

15.1 01/01/1987 14 1 0.1 - - Superfund Amendments and Reauthorization Act of 1986 

P.L. 99-499

20.1 12/01/1990 16 1.5 0.1 2.5 - Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

24.4 10/01/1993 16 1.5 0.1 6.8 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

24.4 10/01/1995 18 2 0.1 4.3 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

24.3 01/01/1996 18 2 - 4.3 - Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

24.4 10/01/1997 21.45 2.85 0.1 - - Taxpayer Relief Act of 1997 P.L. 105-34

24.4 2/ 10/01/1997 21.44 2.86 0.1 - - Transportation Equity Act for the 21st Century P.L. 105-178

GASOHOL 3/

10 Percent Made with Ethanol

3 07/01/1956 3 - - - - Highway Revenue Act of 1956 P.L. 84-627

4 10/01/1959 4 - - - - Federal-Aid Highway Act of 1959 P.L. 86-342

0 01/01/1979 - - - - - Energy Tax Act of 1978 P.L. 95-618

4 1/ 04/01/1983 3.56 0.44 - - - Surface Transportation Assistance Act of 1982 P.L. 97-424

4 1/ 08/01/1984 3 1 - - - Deficit Reduction Act of 1984 P.L. 98-369

3 01/01/1985 2 1 - - - Deficit Reduction Act of 1984 P.L. 98-369

3.1 01/01/1987 2 1 0.1 - - Superfund Amendments and Reauthorization Act of 1986 

P.L. 99-499

8.7 12/01/1990 4 1.5 0.1 2.5 0.6 Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

13 10/01/1993 4 1.5 0.1 6.8 0.6 Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

13 10/01/1995 3.5 2 0.1 6.8 0.6 Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

12.9 01/01/1996 3.4 2 - 6.9 0.6 Omnibus Budget Reconciliation Act of 1990 P.L. 101-508
69

Tax 

Rate

Effective 

Date

Distribution Of Tax

Source of Change

Highway Trust Fund Leaking 

Underground 

Storage Tank 

Trust Fund

General Fund For:

Highway 

Account

Mass 

Transit 

Account

Deficit 

Reduction

Not 

Specified

13 10/01/1997 6.95 2.85 0.1 2.5 0.6 Taxpayer Relief Act of 1997 P.L. 105-34

13 2/ 10/01/1997 6.94 2.86 0.1 2.5 0.6 Transportation Equity Act for the 21st Century P.L. 105-178

13 12/21/2000 7.54 2.86 0.1 2.5 - Consolidated Appropriations Act, 2001 P.L. 106-554

13.1 01/01/2001 7.64 2.86 0.1 2.5 - Transportation Equity Act for the 21st Century P.L. 105-178

13.2 01/01/2003 7.74 2.86 0.1 2.5 - Transportation Equity Act for the 21st Century P.L. 105-178

13.2 10/01/2003 10.24 2.86 0.1 - - Surface Transportation Extension Act of 2004, Part V P.L. 

108-310

18.4 4/ 01/01/2005 15.44 2.86 0.1 - - American Jobs Creation Act of 2004 P.L. 108-357

GASOHOL 3/

7.7 Percent Made with Ethanol

3 07/01/1956 3 - - - - Highway Revenue Act of 1956 P.L. 84-627

4 10/01/1959 4 - - - - Federal-Aid Highway Act of 1959 P.L. 86-342

9 1/ 04/01/1983 8 1 - - - Surface Transportation Assistance Act of 1982 P.L. 97-424

9 1/ 08/01/1984 8 1 - - - Deficit Reduction Act of 1984 P.L. 98-369

9.1 01/01/1987 8 1 0.1 - - Superfund Amendments and Reauthorization Act of 1986 

P.L. 99-499

14.1 12/01/1990 10 1.5 0.1 2.5 - Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

9.942 01/01/1993 5.842 1.5 0.1 2.5 - Energy Policy Act of 1992 P.L. 102-486

14.242 10/01/1993 5.842 1.5 0.1 6.8 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

14.242 10/01/1995 5.342 2 0.1 6.8 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

14.142 01/01/1996 5.242 2 - 6.9 - Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

14.242 10/01/1997 8.792 2.85 0.1 2.5 - Taxpayer Relief Act of 1997 P.L. 105-34

14.242 2/ 10/01/1997 8.782 2.86 0.1 2.5 - Transportation Equity Act for the 21st Century P.L. 105-178

14.319 01/01/2001 8.859 2.86 0.1 2.5 - Transportation Equity Act for the 21st Century P.L. 105-178

14.396 01/01/2003 8.936 2.86 0.1 2.5 - Transportation Equity Act for the 21st Century P.L. 105-178

14.396 10/01/2003 11.436 2.86 0.1 - - Surface Transportation Extension Act of 2004, Part V P.L. 

108-310

18.4 4/ 01/01/2005 15.44 2.86 0.1 - - American Jobs Creation Act of 2004 P.L. 108-357

GASOHOL 3/

5.7 Percent Made with Ethanol

3 07/01/1956 3 - - - - Highway Revenue Act of 1956 P.L. 84-627

4 10/01/1959 4 - - - - Federal-Aid Highway Act of 1959 P.L. 86-342

9 1/ 04/01/1983 8 1 - - - Surface Transportation Assistance Act of 1982 P.L. 97-424

9 1/ 08/01/1984 8 1 - - - Deficit Reduction Act of 1984 P.L. 98-369

9.1 01/01/1987 8 1 0.1 - - Superfund Amendments and Reauthorization Act of 1986 

P.L. 99-499

14.1 12/01/1990 10 1.5 0.1 2.5 - Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

11.022 01/01/1993 6.922 1.5 0.1 2.5 - Energy Policy Act of 1992 P.L. 102-486

15.322 10/01/1993 6.922 1.5 0.1 6.8 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

15.322 10/01/1995 6.422 2 0.1 6.8 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

15.222 01/01/1996 6.322 2 - 6.9 - Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

15.322 10/01/1997 9.872 2.85 0.1 2.5 - Taxpayer Relief Act of 1997 P.L. 105-34

15.322 2/ 10/01/1997 9.862 2.86 0.1 2.5 - Transportation Equity Act for the 21st Century P.L. 105-178

15.379 01/01/2001 9.919 2.86 0.1 2.5 - Transportation Equity Act for the 21st Century P.L. 105-178

15.436 01/01/2003 9.976 2.86 0.1 2.5 - Transportation Equity Act for the 21st Century P.L. 105-178
70

Tax 

Rate

Effective 

Date

Distribution Of Tax

Source of Change

Highway Trust Fund Leaking 

Underground 

Storage Tank 

Trust Fund

General Fund For:

Highway 

Account

Mass 

Transit 

Account

Deficit 

Reduction

Not 

Specified

15.436 10/01/2003 12.476 2.86 0.1 - - Surface Transportation Extension Act of 2004, Part V P.L. 

108-310

18.4 4/ 01/01/2005 15.44 2.86 0.1 - - American Jobs Creation Act of 2004 P.L. 108-357

SPECIAL FUELS

General Rates

3 07/01/1956 3 - - - - Highway Revenue Act of 1956 P.L. 84-627

4 10/01/1959 4 - - - - Federal-Aid Highway Act of 1959 P.L. 86-342

9 1/ 04/01/1983 8 1 - - - Surface Transportation Assistance Act of 1982 P.L. 97-424

9 1/ 08/01/1984 8 1 - - - Deficit Reduction Act of 1984 P.L. 98-369

9.1 01/01/1987 8 1 0.1 - - Superfund Amendments and Reauthorization Act of 1986 

P.L. 99-499

14.1 12/01/1990 10 1.5 0.1 2.5 - Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

18.4 10/01/1993 10 1.5 0.1 6.8 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

18.4 10/01/1995 12 2 0.1 4.3 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

18.3 01/01/1996 12 2 - 4.3 - Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

18.4 10/01/1997 15.45 2.85 0.1 - - Taxpayer Relief Act of 1997 P.L. 105-34

18.4 2/ 10/01/1997 15.44 2.86 0.1 - - Transportation Equity Act for the 21st Century P.L. 105-178

SPECIAL FUELS

Liquefied Petroleum Gas 5/

3 07/01/1956 3 - - - - Highway Revenue Act of 1956 P.L. 84-627

4 10/01/1959 4 - - - - Federal-Aid Highway Act of 1959 P.L. 86-342

9 1/ 04/01/1983 8 1 - - - Surface Transportation Assistance Act of 1982 P.L. 97-424

9 1/ 08/01/1984 8 1 - - - Deficit Reduction Act of 1984 P.L. 98-369

14 12/01/1990 10 1.5 - 2.5 - Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

18.3 10/01/1993 10 1.5 - 6.8 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

18.3 10/01/1995 12 2 - 4.3 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

13.6 10/01/1997 10.75 2.85 - - - Taxpayer Relief Act of 1997 P.L. 105-34

13.6 2/ 10/01/1997 11.47 2.13 - - - Transportation Equity Act for the 21st Century P.L. 105-178

18.3 10/01/2006 16.17 2.13 - - - Safe, Accountable, Flexible, Efficient Transportation Equity 

Act: A Legacy for Users P.L. 109-59

18.3 5/ 01/01/2016 15.42 2.88 - - - Surface Transportation and Veterans Health Care Choice 

Improvement Act of 2015 P.L. 114-41

SPECIAL FUELS

Liquefied Natural Gas 6/

3 07/01/1956 3 - - - - Highway Revenue Act of 1956 P.L. 84-627

4 10/01/1959 4 - - - - Federal-Aid Highway Act of 1959 P.L. 86-342

9 1/ 04/01/1983 8 1 - - - Surface Transportation Assistance Act of 1982 P.L. 97-424

9 1/ 08/01/1984 8 1 - - - Deficit Reduction Act of 1984 P.L. 98-369

9.1 01/01/1987 8 1 0.1 - - Superfund Amendments and Reauthorization Act of 1986 

P.L. 99-499

14.1 12/01/1990 10 1.5 0.1 2.5 - Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

18.4 10/01/1993 10 1.5 0.1 6.8 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

18.4 10/01/1995 12 2 0.1 4.3 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

18.3 01/01/1996 12 2 - 4.3 - Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

11.9 10/01/1997 9.05 2.85 - - - Taxpayer Relief Act of 1997 P.L. 105-34
71

Tax 

Rate

Effective 

Date

Distribution Of Tax

Source of Change

Highway Trust Fund Leaking 

Underground 

Storage Tank 

Trust Fund

General Fund For:

Highway 

Account

Mass 

Transit 

Account

Deficit 

Reduction

Not 

Specified

11.9 2/ 10/01/1997 10.04 1.86 - - - Transportation Equity Act for the 21st Century P.L. 105-178

24.3 10/01/2006 22.44 1.86 - - - Safe, Accountable, Flexible, Efficient Transportation Equity 

Act: A Legacy for Users P.L. 109-59

24.3 6/ 10/01/2016 21.08 3.22 - - - Surface Transportation and Veterans Health Care Choice 

Improvement Act of 2015 P.L. 114-41

SPECIAL FUELS

M85 and M100 with Methanol from Natural Gas 7/

3 07/01/1956 3 - - - - Highway Revenue Act of 1956 P.L. 84-627

4 10/01/1959 4 - - - - Federal-Aid Highway Act of 1959 P.L. 86-342

9 04/01/1983 8 1 - - - Surface Transportation Assistance Act of 1982 P.L. 97-424

4.5 08/01/1984 3.5 1 - - - Deficit Reduction Act of 1984 P.L. 98-369

4.6 01/01/1987 3.5 1 0.1 - - Superfund Amendments and Reauthorization Act of 1986 

P.L. 99-499

7.1 12/01/1990 4.25 1.5 0.1 1.25 - Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

11.4 10/01/1993 4.25 1.5 0.1 5.55 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

11.4 10/01/1995 5 2 0.1 4.3 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

11.3 01/01/1996 5 2 - 4.3 - Omnibus Budget Reconciliation Act of 1990 P.L. 101-508

9.25 10/01/1997 6.3 2.85 0.1 - - Taxpayer Relief Act of 1997 P.L. 105-34

9.25 2/ 10/01/1997 7.72 1.43 0.1 - - Transportation Equity Act for the 21st Century P.L. 105-178

COMPRESSED NATURAL GAS 8/

(See footnote for units)

48.54 10/01/1993 - - - 48.54 - Omnibus Budget Reconciliation Act of 1993 P.L. 103-66

48.54 10/01/1997 38.94 9.6 - - - Taxpayer Relief Act of 1997 P.L. 105-34

48.54 2/ 10/01/1997 38.83 9.71 - - - Transportation Equity Act for the 21st Century P.L. 105-178

18.3 8/ 10/01/2006 16.981 1.319 - - - Safe, Accountable, Flexible, Efficient Transportation Equity 

Act: A Legacy for Users P.L. 109-59

18.3 8/ 10/01/2016 17.1 1.2 - - - Surface Transportation and Veterans Health Care Choice 

Improvement Act of 2015 P.L. 114-41

1/ The Surface Transportation Assistance Act of 1982 (Public Law 97-424) provided that the Mass Transit Account would receive one-ninth of the fuel tax 

proceeds. The Deficit Reduction Act of 1984 (Public Law 98-369) provided that the Mass Transit Account would receive 1 cent per gallon. For most fuels, the 

change had no practical effect.

2/ The Transportation Equity Act for the 21st Century retroactively revised the Mass Transit Account share of the fuel tax.

3/ Gasohol was not defined in Federal tax law prior to January 1, 1979. The products later defined as gasohol were taxable, to the extent they existed, under the 

provisions of the gasoline tax. Effective January 1, 1979, the Energy Tax Act of 1978 defined gasohol to be a blend of gasoline and at least 10 percent (by 

volume) alcohol, excluding alcohol made from petroleum, natural gas, or goal. Blends with less than 10 percent alcohol were taxable as gasoline. The Energy 

Policy Act of 1992 expanded the definition of gasohol effective January 1, 1993. Under that Act, the product now called 10-percent gasohol corresponds to the 

definition under the Energy Tax Act of 1978. The Energy Policy Act of 1992 also defined two additional types of gasohol. The term 7.7 percent gasohol includes 

gasoline-alcohol blends where the alcohol content is at least 7.7 percent but less than 10 percent. The term 5.7 percent gasohol includes gasoline-alcohol 

blends where the alcohol content is at least 5.7 percent but less than 7.7 percent. The rates shown are for gasohol made with ethanol. Different rates applied to 

gasohol made with methanol, but such blends were never in common use.

4/ Effective January 1, 2005, gasohol’s partial exemption from the gasoline tax was replaced by an equivalent excise tax credit paid from the General Fund of the 

Treasury. No further history on the credit is provided.

5/ Prior to January 1, 2016, the liquefied petroleum gas (LPG) tax rates are in cents per gallon. Effective January 1, 2016, the rates are expressed in cents per 

gasoline-equivalent gallon. One gallon of gasoline has equivalent energy content to 1.353 gallons of LPG.

6/ Prior to January 1, 2016, the liquefied natural gas (LNG) tax rates are in cents per gallon. Effective January 1, 2016, the rates are expressed in cents per dieselequivalent gallon. One gallon of diesel fuel has equivalent energy content to 1.71 gallons of LNG.

7/ The rates shown are for gasoline-alcohol blends where the alcohol is methanol produced from natural gas. Other rates apply to blends where the alcohol is 

ethanol or is methanol produced from sources other than natural gas.

8/ Prior to October 1, 1993, compressed natural gas (CNG) was not taxed. From October 1, 1993 through September 30, 2006, CNG was taxed at 48.54 cents per 

thousand cubic feet. Effective October 1, 2006, the tax rate for compressed natural gas is 18.3 cents per gasoline-equivalent gallon. The Internal Revenue 

Service determined that one gallon of gasoline was energy equivalent to 126.67 cubic feet. Effective January 1, 2016, the Surface Transportation and Veterans 

Health Care Choice Improvement Act of 2015 specified that one gallon of gasoline was energy equivalent to 123.57 cubic feet of CNG.
72

Endnotes

1

 In the government-wide Federal budgetary context, the term “apportionment” is at times used to refer to the 

action by which the Office of Management and Budget (OMB) distributes amounts available for obligation, 

including budgetary reserves established pursuant to law, in an appropriation or fund account.

2

 TEA-21 was enacted on June 9, 1998. A technical correction act to the TEA-21 was included as Title IX of 

Public Law 105-206, the Internal Revenue Restructuring and Reform Act of 1998, enacted July 22, 1998. Title 

IX is cited as the “TEA 21 Restoration Act.” 

3

 23 U.S.C. 167(i).

4

 23 U.S.C. 117. 

5

 The Legislative Reorganization Act of 1946. 

6

 Although there are additional steps between committee approval and consideration on the floor of Congress, such 

as passing through the Rules Committee in the House, they are omitted for brevity.

7

 There are two other forms of budget authority: borrowing authority and authority related to the use of offsetting 

receipts and collections. These are not discussed in this document.

8

 Section 4 of Public Law 67-244, enacted June 19, 1922.

9

 Section 401(d)(1)(B) of Public Law 93-344. 

10 Beginning in FY 2008, the revenues from highway-user taxes deposited in the Highway Account of the Highway 

Trust Fund were insufficient to support the levels of funding authorized for the FAHP and other programs from 

the Highway Account (see Chapter 7 of this report for more information). The result was that less than 90 

percent of the Highway Account receipts were attributable to highway-user taxes. Despite that fact, the Congress 

continued to authorize contract authority for the FAHP. This was possible for one of two reasons: (1) no one 

raised a point of order against the bill authorizing contract authority; or (2) Congress agreed to waive any point of 

order against the bill. 

11 In lieu of an explicit mention of 23 U.S.C. 118(a), Congress will at times instead use a more general reference to 

a program’s funding being “available for obligation in the same manner is if the funds were apportioned under 

chapter 1 of title 23”; see, for example, section 1119(g)(2) of Public Law 109-59. This also makes the funding 

contract authority. 

12 Section 1123 of Public Law 114-94. 

13 Section 1437 of Public Law 114-94. 

14 23 U.S.C. 118(a). 

15 If FHWA apportions funds in a manner inconsistent with statute, GAO has opined that the Agency must adjust the 

apportionments appropriately (41 Comp. Gen. 16 (1961)).
73

16 23 U.S.C. 119(f)(1)(A)(ii).

17 23 U.S.C. 144(h)(5).

18 23 U.S.C. 116(d).

19 23 U.S.C. 505. 

20 23 U.S.C. 133(h).

21 23 U.S.C. 133(f). 

22 Section 1437 of Public Law 114-94. 

23 23 U.S.C. 133(d)(1)(A).

24 23 U.S.C. 133(d)(4)(A). 

25 23 U.S.C. 133(d)(6). 

26 23 U.S.C. 133(d)(1)(B). 

27 23 U.S.C. 133(h)(5). 

28 23 U.S.C. 133(h)(2). 

29 Section 1101(b)(3) of Public Law 114-94. 

30 Codified in title 23 as the Nationally Significant Freight and Highway Projects program (23 U.S.C. 117). 

31 Section 1702 of Public Law 109-59.

32 Section 1934 of Public Law 109-59.

33 Section 10212 of Public Law 109-59.

34 Section 1302 of Public Law 109-280 and sections 101(s)(4) and 112 of Public Law 110-244. 

35 Section 413 of Public Law 111-147.

36 The deficit target amounts were amended and the target for a zero deficit delayed until FY 1993 by the Balanced 

Budget and Emergency Deficit Control Reaffirmation Act of 1987. 

37 Certain programs were exempt from sequester, including Social Security, Medicaid, veteran’s compensation, 

Aid to Families with Dependent Children, food stamps, and others. Certain health care programs, such as 

Medicare and veterans’ health care, were subject to sequester, but the percentage that could be sequestered was 

capped.

38 23 U.S.C. 106(a). 

39 23 U.S.C. 118(b)(2). 

40 23 U.S.C. 118(b)(2). 
74

41 23 U.S.C. 120. 

42 23 U.S.C. 120(a). 

43 23 U.S.C. 120(b). 

44 23 U.S.C. 120(e). 

45 23 U.S.C. 143. 

46 23 U.S.C. 120(c)(1). 

47 23 U.S.C. 120(c)(3).

48 For many years Federal law prohibited the use of tapered match by making each individual progress payment 

subject to the project-specific Federal share. However, section 1302(2) of the Transportation Equity Act for the 

21st Century (Public Law 105-178) struck that provision of law—and with it the prohibition on tapered match. 

49 23 U.S.C. 121(b). 

50 23 U.S.C. 323. 

51 23 U.S.C. 120(i). 

52 23 U.S.C. 120(j). 

53 23 U.S.C. 120(k). 

54 23 U.S.C. 206(f)(4).

55 23 U.S.C. 206(f)(3).

56 Public Law 93-344, enacted July 12, 1974. 

57 Section 1102(b) of Public Law 114-94. 

58 See for example section 120 of Division L of Public Law 114-113, the Consolidated Appropriations Act, 2016. 

59 Section 1102(c)(1) of Public Law 114-94. 

60 Section 1102(c)(3) of Public Law 114-94. 

61 Section 1102(e) of Public Law 114-94. 

62 Section 1102(c) of Public Law 114-94. 

63 Section 1102(d) of Public Law 114-94. 

64 Section 1102(f) of Public Law 114-94. 

65 This is a rare occurrence. The last such action was in 1980 when an additional $1.4 billion in liquidating cash 

was provided by the Supplemental Appropriations and Rescission Act, 1980 (Public Law 96-304). 

66 23 U.S.C. 121(c). 
75

67 The Federal-aid Primary and Secondary Systems were the roads eligible for Federal assistance at the time.

68 Most fuel taxes continue at the rate of 4.4 cents per gallon after this date and the heavy vehicle use tax continues 

through September 30, 2023, but deposit of the proceeds in the Highway Trust Fund ceases after September 30, 

2022. 

69 The Surface Transportation Assistance Act of 1982 required one-ninth of the fuel tax revenue collected at that 

time—about 1 cent per gallon—to be deposited in the Mass Transit Account. This provision has been amended 

several times, and the “one-ninth” ratio no longer applies. Effective October 1, 1997, the deposit to the Mass 

Transit Account is 2.86 cents per gallon of most taxable highway motor fuels. 

70 Effective January 1, 1987, the Leaking Underground Storage Tank Trust Fund was established and an additional 

tax of 0.1 cent per gallon on highway and other fuels was dedicated to this fund. 

71 In the case of gasohol and certain other alcohol blends, the 2.5 cents per gallon continued to be directed to the 

General Fund. 

72 Motor Carrier Safety Act of 1984, codified in 49 U.S.C. 521. 

73 Section 9503(b)(5) of the Internal Revenue Code of 1986, classified to 26 U.S.C 9503(b)(5). 

74 Section 9503(b)(5) of the Internal Revenue Code of 1986, classified to 26 U.S.C. 9503(b)(5). 

75 Section 9602(b) of the Internal Revenue Code of 1986, classified to 26 U.S.C. 9602(b).

76 Section 9004(a) of Public Law 105-178 prohibited crediting interest to the Highway Trust Fund. Section 441 of 

Public Law 111-147 subsequently eliminated this prohibition, re-instating the Trust Fund’s ability to collect 

interest.

77 Section 9601 of the Internal Revenue Code of 1986, classified to 26 U.S.C. 9601. The law requires deposits to be 

made at least monthly, and the practice is to make such deposits twice each month.

78 23 U.S.C. 104(c)(1)(B). 

79 Section 2002 of Public Law 114-41, amending section 9503(f) of the Internal Revenue Code of 1986, as in effect 

on July 31, 2015. 

80 Previously called the Aquatic Resources Trust Fund

81 Section 9503(c) of the Internal Revenue Code of 1986, classified to 26 U.S.C. 9503(c). 

82 Aviation kerosene used in commercial aviation is taxed at 4.4 cents per gallon and fuel used in noncommercial 

(general) aviation is taxed at 21.9 cents per gallon. Each of these rates include the 0.1 cent per gallon for the 

LUST Trust Fund).

83 The Byrd Amendment is named for Senator Harry Flood Byrd of Virginia who was a member of the Senate 

Finance Committee at the time the Highway Revenue Act of 1956 was being debated. His concern for the future 

solvency of the Highway Trust Fund led to the amendment of the bill. 

84 The Rostenkowski Rule is named for Representative Dan Rostenkowski of Illinois, who chaired the House 

Committee on Ways and Means during the creation of the Mass Transit Account.

85 Section 11102 of Public Law 109-59. 
76

86 Section 9503(d) of the Internal Revenue Code of 1986, classified to 26 U.S.C. 9503(d). 

87 For example, the Highway Account balance dropped dramatically enough during FY 2008 to lead Congress to 

transfer in additional cash from the General Fund. However, throughout that entire period, the Highway Account 

continued to pass the Byrd Test.