Highway Bridge Conditions: Issues for Congress

April 13, 2016 – August 31, 2020 R44459

Highway Bridge Conditions:
Issues for Congress
Updated August 31, 2020
Congressional Research Service
https://crsreports.congress.gov
R44459

Highway Bridge Conditions: Issues for Congress

Summary
Of the 617,000 public road bridges in the United States, about 46,000 (7.5%) were classified as in
poor condition in 2019. These data, along with some highly publicized incidents involving
highway bridges, have led to claims that the United States is experiencing a crisis with respect to
bridge condition. Federal data do not substantiate this assertion. The number of bridges classified
as poor has consistently fallen over the past decade, totaling about 15,000 fewer bridges in poor
condition in 2019 than in 2009. Although improvements have been made in most states, there
remain major differences in the share of bridges in poor condition. About 22% of bridges in
Rhode Island are classified as poor, whereas in Nevada the share is 1%.
The vast majority of bridges in poor condition, over four out of five, are in rural areas. These
bridges tend to be small and relatively lightly traveled. In urban areas, bridges in poor condition,
while far fewer, are generally much larger and, therefore, more expensive to fix: 59% of the deck
area classified as in poor condition is on urban bridges. Bridges on roads carrying heavy traffic
loads, particularly Interstate Highway bridges, are generally in better condition than those on
more lightly traveled routes.
Federal funding for bridge building, reconstruction, and repair is authorized in surface
transportation acts. The most recent authorization is the Fixing America’s Surface Transportation
Act (FAST Act; P.L. 114-94), which was enacted on December 4, 2015. The FAST Act did not
authorize a program dedicated to highway bridges, but it made bridge projects broadly eligible for
federal funding under the largest of the highway formula programs and eligible on a case-by-case
basis under other programs. Bridges that are damaged by natural disasters or catastrophic events
may also be eligible for Emergency Relief Program funds.
The condition of roads, in particular urban roads, has not experienced the same degree of
improvement as the condition of bridges. This disparity raises the policy question of what priority
should go to bridge repairs as opposed to roadway repairs. Congress has implicitly addressed this
issue by giving states greater flexibility to use federal funding for roads or for bridges, at their
discretion. Laws enacted in 2012 and again in 2015 have given states near-total authority to
determine which projects to fund with federal highway funds, within broad guidelines established
by Congress. As it considers reauthorization of the FAST Act, Congress may want to evaluate
whether states are making sufficient progress in reducing the number of structurally deficient
bridges and whether future laws should reestablish specific requirements for bridge spending.

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Background
The United States has approximately 617,000 bridges on public roads subject to the National
Bridge Inspection Standards (NBIS) mandated by Congress. About 48% of these bridges are
owned by state governments, and 50% are owned by local governments. State governments
generally own the larger and more heavily traveled bridges, such as those on the Interstate
Highway system. Less than 2% of highway bridges are owned by the federal government,
primarily those on federally owned land.1
About 9% of all bridges carry Interstate Highways, and another 14% serve principal arterial
highways other than Interstates.2 Interstate and other principal arterial bridges carry about 80% of
average daily bridge traffic. The highest traffic loads are on Interstate Highway bridges in urban
areas; these account for only 5% of all bridges but carried 37% of average daily bridge traffic in
2019.3
Bridge Conditions
Federal law requires states to inspect public road bridges periodically and to report their findings
to the Federal Highway Administration (FHWA). This information permits FHWA to characterize
the existing condition of bridges as good, fair, or poor, and to identify those bridges that are
structurally deficient. To implement the performance management system for bridges enacted in
the Moving Ahead for Progress in the 21st Century Act (MAP-21;), FHWA changed the way it
categorizes bridges, including how it defines structural deficiency. Prior to the change,
structurally deficient bridges included those in poor condition and some others, such as those with
an inadequate waterway opening. Beginning in 2018, “structurally deficient” was also termed
“poor.”4 A bridge classified as poor/structurally deficient is not necessarily unsafe, but may
require the posting of a vehicle weight restriction. When officials determine that a bridge is
unsafe, it is closed to traffic.
A bridge is considered in good condition if the deck, superstructure, substructure, and culvert are
rated at least 7 on a 0-to-9 scale. If any of these bridge elements is rated 5 or 6, a bridge is
considered in fair condition. A bridge is considered in poor condition if any element is rated 4 or
less. In 2019, 45.3% of bridges were considered good, 47.2% fair, and 7.5% poor. Measured by
the percentage of bridges rated poor, bridge condition has improved since 2009. This is a drop of
about 15,000 in the number of bridges considered poor. However, the percentage of bridges in
good condition has also dropped over this period (Table 1).

1 The standards, authorized at 23 U.S.C. §144, cover bridges located on public roads that are 20 feet (6.1 meters) in
length or longer. Federal Highway Administration (FHWA), “Bridge Condition by Owner, 2019,” National Bridge
Inventory, at http://www.fhwa.dot.gov/bridge/britab.cfm.
2 Arterials, including Interstates, are roads designed to provide for relatively long trips at high speed and usually have
multiple lanes and limited access. Principal arterials exclude rural and urban minor arterials. FHWA, “Bridge Condition
by Functional Classification, 2019,” National Bridge Inventory, at http://www.fhwa.dot.gov/bridge/britab.cfm.
3 FHWA, “Bridge Condition by Functional Classification, Average Daily Travel (ADT), 2019,” National Bridge
Inventory, at http://www.fhwa.dot.gov/bridge/britab.cfm.
4 FHWA, “National Performance Management Measures; Assessing Pavement Condition for the National Highway
Performance Program and Bridge Condition for the National Highway Performance Program,” 82 Federal Register
5886, January 18, 2017.
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Table 1. Bridge Condition Ratings, 2009-2019
Percent
Year
Good
Fair
Poor
2009
47.5
42.3
10.1
2010
47.4
42.7
9.8
2011
47.2
43.1
9.6
2012
47.3
43.3
9.4
2013
47.3
43.7
9.0
2014
47.1
44.2
8.7
2015
47.3
44.4
8.3
2016
47.4
44.6
7.9
2017
46,8
45.4
7.7
2018
46.0
46.4
7.6
2019
45.3
47.2
7.5
Source: Federal Highway Administration, National Bridge Inventory, Highway Bridge Condition by
Highway System, at https://www.fhwa.dot.gov/bridge/britab.cfm.
In terms of the number of bridges, poor condition is principally a problem affecting rural areas,
particularly bridges on local rural roads. In 2019, 80% of bridges rated poor were in rural areas
and 50% of bridges in poor condition were on local rural roads. However, urban bridges in poor
condition are generally much larger and, therefore, more expensive to fix. In 2019, 59% of the
deck area of bridges in poor condition was in urban areas, with 40% on urban Interstates and
other principal arterials.5
Nevertheless, bridges on Interstate Highways are generally in better condition than those on more
lightly traveled routes: 3.3% of urban Interstate Highway bridges were considered poor in 2019,
less than half of the 7.3% of urban bridges on local roads classified as poor.6 Likewise, 2.6% of
rural Interstate Highway bridges were poor in 2019, about a fourth of the 11.4% of rural bridges
on local roads rated poor.
Locally owned bridges, typically carrying local roads, are more likely to be in poor condition. In
2019, 9.8% of bridges owned by local government were classified as poor, compared with 5.0%
of state-owned bridges. For bridge condition ratings by state and territory, see Appendix A.
Future Bridge Funding Needs
Every two years or so, FHWA assesses the condition and performance of the nation’s highways
and bridges, documents current spending by all levels of government, and estimates future
spending needs to maintain or improve current conditions and performance.7 As with any attempt

5 FHWA, “Bridge Condition by Functional Classification,” National Bridge Inventory, at https://www.fhwa.dot.gov/
bridge/fc.cfm.
6 Interstates are the highest class of roadways in FHWA’s functional classification system, and local roads are the
lowest.
7 The “maintain” scenario assumes that capital investment changes so that selected measures of bridge performance in
2034 are maintained at their 2014 levels. The “improve” scenario is the level of spending in which the investment is
made in all projects by 2034 for which the economic benefits are equal to or greater than the economic costs.
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Highway Bridge Conditions: Issues for Congress

to forecast future conditions, a host of simplifying assumptions, omissions, and data problems
influence these estimates. Among other things, the estimates rely on forecasts of travel demand.
Despite such uncertainties and assumptions, these estimates provide a way to assess the level of
current spending compared with what would be needed in the future under different scenarios.
The most recent assessment was published in 2019 based on 2014 data. Represented in 2019
dollars, this assessment showed that $15.6 billion was spent on bridge rehabilitation or
replacement by governments at all levels in 2014. An additional $1.7 billion was spent on the
construction of new bridges.8 Because of the modeling involved, FHWA’s future needs estimates
for bridges are limited to fixing deficiencies in existing bridges only when the benefits outweigh
the costs. It estimated that fixing all bridge deficiencies existing in 2014 would cost $135 billion
(in 2019 dollars), which was eight times the level of spending on bridge rehabilitation and
replacement in 2014.9
Of course, fixing all deficient bridges overnight is not feasible. FHWA, therefore, estimated how
this investment backlog may change at various levels of spending over the 2015-2034 period,
taking into account the deterioration of existing bridges over that period. The results of this
analysis are seen in Figure 1. To eliminate the backlog by 2034 would require an investment of
$24.6 billion annually (in 2019 dollars). If the $15.6 billion spending level of 2014 were to
continue, the total bridge reconstruction backlog would decline by roughly 61% by 2034.
Figure 1. Estimated Effect of Various Spending Levels on Bridge Investment Backlog
Average Annual Spending for 20 Years

Source: Federal Highway Administration and Federal Transit Administration, Status of the Nation’s Highways,
Bridges, and Transit: Conditions and Performance, 23rd Edition, January 2019, exhibit 10-15.
Notes: The current funding level is for 2014 and the 20-year spending scenarios are for 2015 through 2034.
CRS adjusted the data expressed in 2014 dol ars to 2019 dol ars using the implicit GDP deflator.

8 Federal Highway Administration and Federal Transit Administration, Status of the Nation’s Highways, Bridges, and
Transit: Conditions and Performance, 23rd Edition, January 2019, pp. 2-15.
9 Ibid., exhibit 7-9.
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Federal and State Roles
Federal assistance for the maintenance, rehabilitation, and construction of highway bridges comes
principally through the Federal-Aid Highway Program administered by FHWA. FHWA, however,
does not determine which bridges should benefit from federal funding. Almost all funding under
the Federal-Aid Highway Program is distributed to state departments of transportation, which
determine, for the most part, where and on what the money is spent. States must comply with
detailed federal planning guidelines and performance management measures as part of the
decisionmaking process, but otherwise they are free to spend their federal highway funds in any
way consistent with federal laws and regulations.10 Bridge projects are developed at the state
level, and state departments of transportation let the contracts, oversee the construction process,
and provide for the inspection of bridges.11
The Highway Bridge Program, a stand-alone program for highway bridges that was formerly part
of the Federal-Aid Highway Program, was terminated at the end of FY2012.The current law
authorizing highway spending, the 2015 Fixing America’s Surface Transportation Act (FAST Act;
P.L. 114-94), does not include a program specifically targeting bridges.12 Instead, the law makes
bridge projects eligible for funding from three programs that distribute funds to the states under
formulas specified in law: the National Highway Performance Program (NHPP), the Surface
Transportation Block Grant Program (STBG), and the National Highway Freight Program
(NHFP). Under all three programs, the states determine how much of their federal funding is
spent on bridges as opposed to other uses, primarily highway construction and improvement.
These funds may also be used for the seismic retrofitting of bridges to reduce earthquake failure
risk.13
Depending on the specific use, funding from other formula programs may also be used on bridge
projects on a case-by-case basis. In addition, states are allowed to transfer (“flex”) up to 50% of
each formula program’s apportioned funds to other formula programs.14 A related discretionary
grant program, the Nationally Significant Freight and Highway Projects Program (renamed
INFRA), also may provide funding for large bridge projects on a competitive grant basis.15
Beginning in FY2018, some bridge funding has also been provided by appropriations outside the
authorization process. The Consolidated Appropriations Act, 2018 (P.L. 115-141), included $225
million for a competitive bridge program for states with a population density of 100 per square
mile or less. The Consolidated Appropriations Act, 2019 (P.L. 116-6), provided $475 million for a
Bridge Replacement and Rehabilitation Program, to be distributed by formula to states for which

10 FHWA’s Final Rule for National Performance Management Measures: Assessing Pavement Condition for the
National Highway Performance Program and Bridge Condition for the National Highway Performance Program,
became effective on February 17, 2017. See https://www.federalregister.gov/documents/2017/01/18/2017-00550/
national-performance-management-measures-assessing-pavement-condition-for-the-national-highway.
11 CRS Report R44332, Federal-Aid Highway Program (FAHP): In Brief, by Robert S. Kirk.
12 CRS Report R44388, Surface Transportation Funding and Programs Under the Fixing America’s Surface
Transportation Act (FAST Act; P.L. 114-94), coordinated by Robert S. Kirk.
13 See CRS Report R41746, Earthquake Risk and U.S. Highway Infrastructure: Frequently Asked Questions, by
William J. Mallett, Nicole T. Carter, and Peter Folger.
14 Metropolitan Planning Program funds and sub-allocated funds under the Surface Transportation Block Grant
Program (STBG) are among those shielded from transfer. See FHWA, Transferability of Apportioned Program
Funding under 23 U.S.C. 126, at https://www.fhwa.dot.gov/cfo/23usc126_transferability.cfm.
15 Unlike the other highway programs discussed in this report, INFRA is administered by the Office of the Secretary of
Transportation, not by FHWA.
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the percent of total bridge deck area classified as poor is at least 7.5%. The Further Consolidated
Appropriations Act, 2020 (P.L. 116-94), provided $1.15 billion for the Bridge Replacement and
Rehabilitation Program but broadened the eligibility to states for which the percentage of total
bridge deck area classified as poor is at least 5%. For these three years Congress has in effect
pursued a two-pronged approach toward bridge funding, making bridges eligible for funding at
state discretion under the large highway programs established in authorization acts supplemented
by targeted bridge funds provided in annual appropriations acts.
FHWA imposes certain performance measures that states must meet to avoid tighter federal
restrictions on highway spending. For example, if more than 10% of the deck area of a state’s
bridges on the National Highway System (which consists of the Interstate Highway System and
most other principal arterial roads) is structurally deficient, the state is required to dedicate an
amount of its NHPP funds equal to 50% of its FY2009 spending under the former Highway
Bridge Program to bridge projects.16
Section 1111 of MAP-21 had also required FHWA, in consultation with states and other federal
agencies, to classify public road bridges according to “serviceability, safety, and essentiality for
public use ... [and,] based on that classification, assign each a risk-based priority for systematic
preventive maintenance, replacement or rehabilitation.” FHWA has not completed a rulemaking
implementing this requirement.17
Table 2 shows the total obligation of federal funding for bridges, including both funds from the
former Highway Bridge Program and those from all other programmatic sources, from FY2012
through FY2019. The table also compares obligations from all programs in current dollars and
adjusts these totals to show the impact of project cost inflation during this period.

16 For a definition of the National Highway System, see FHWA, National Highway System, “What Is the National
Highway System?” at http://www.fhwa.dot.gov/planning/national_highway_system/.
17 Because of possible conflicts with a MAP-21 requirement that states develop risk-based asset management plans
under the NHPP, FHWA has chosen not to pursue the rulemaking, in Letter from Federal Highway Administration,
Congressional Affairs Team, to Robert S. Kirk, Specialist in Transportation Policy, June 3, 2020.
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Table 2. Trends in Federal Bridge Obligations, FY2012-FY2019
(current and inflation-adjusted dollars in millions)

FY2012 FY2013 FY2014 FY2015 FY2016 FY2017 FY2018 FY2019
Total (Current $)
$6,014
$6,484
$6,803
$6,804
$7,095
$6,666
$7,092
$7,365
% Change from
-15%
+8%
+5%
0.0%
+4%
-6%
+6%
+4%
Previous Year
Highway Bridge
$3,575
$961
$221
$243
$80
$72
$44
$2
Program (pre MAP-
21 funds)
Surface
$477
$548
$708
$604
$587
$558
$1,662
$2,212
Transportation
Program
National Highway
—
$3,018
$3,673
$3,638
$3,910
$3,937
$3,790
$4,033
Performance
Program
All Other Programs $1,962
$1,957
$2,201
$2,319
$2,518
$2,099
$1,596
$1,118
Total (Inflation
$6,014
$6,319
$6,550
$6,550
$6,808
$6,202
$6,292
6,398
Adjusted, 2012$)
% Change from
-19%
+5%
+4%
0.0%
+4%
-9%
+1%
+2%
Previous Year
Sources: FHWA; Cost adjustments calculated by CRS using Bureau of Economic Analysis, Price Indexes for Gross
Government Fixed Investment by Type, National Income and Product Accounts Table 5.9.4, Line 40: State and local
highways and streets. Weighted average used to approximate fiscal years.
Notes: For a detailed table of bridge obligations for these years, see Appendix B. Totals reflect ongoing
obligations of funds under prior authorizations. Totals may not add due to rounding. Highway Bridge Program
funding for FY2013-FY2019 reflects funds unobligated when the program was discontinued at the end of FY2012.
Surface Transportation Program includes both Surface Transportation Program and Surface Transportation
Block Grant Program funds.
In FY2012, after most American Recovery and Reconstruction Act (ARRA; P.L. 111-5) stimulus
funds had been obligated, the obligation of federal funds for bridges fell roughly 15% below
FY2011 obligations. From FY2012 through FY2019 the obligation of funds for bridges grew
nearly 22.5% in current dollar terms. Even so, adjusted for inflation, in FY2019 obligations for
bridge work were only 6% higher than bridge obligations in FY2012.
Bridge Inspection
Under the National Bridge Inspection Program, all bridges longer than 20 feet on public roads
must be inspected by qualified inspectors, based on federally defined requirements. Federal
agencies are subject to the same requirements for federally owned bridges, such as those on
federal lands. Data from these inspections are reported to FHWA, which uses them to compile a
list of bridges in poor condition. States may use this information to identify which bridges need
replacement or repair.18

18 The National Bridge Inspection Program was initiated in 1968 following the 1967 collapse of the so-called Silver
Bridge over the Ohio River. The National Bridge Inspection Standards were first issued in 1971. See FHWA, “Tables
of Frequently Requested NBI Information,” at http://www.fhwa.dot.gov/bridge/britab.cfm.
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FHWA sets the standards for bridge inspection through the National Bridge Inspection Standards
(NBIS).19 The NBIS set forth how, with what frequency, and by whom bridge inspection is to be
completed. The standards provide the following
 Each state is responsible for the inspection of all public highway bridges within
the state except for those owned by the federal government or Indian tribes.
Although the state may delegate some bridge inspection responsibilities to
smaller units of government, the responsibility for having the inspections done in
conformance with federal requirements remains with the state.
 Inspections can be done by anyone qualified under the NBIS, which set forth
standards for qualification and training. The inspectors may be state employees,
consultants to the states, or others.
 Inspection of a federally owned bridge is the responsibility of the federal agency
that owns the bridge.
 In general, the required interval of inspection is every 24 months. States are to
identify bridges that require less than a 24-month interval. States can also,
however, request FHWA approval to inspect certain bridges at intervals as long as
48 months. The interval for an underwater inspection is generally 60 months but
may be increased to 72 months with FHWA permission. Fracture-critical
members must undergo a hands-on inspection at intervals not to exceed 24
months.20
 The most common on-site inspection is a visual inspection by trained inspectors,
one of whom must meet the additional training requirements of a team leader.
Damage and special inspections do not require the presence of a team leader.
 Load rating of a bridge must be under the responsibility of a registered
professional engineer. Structures that cannot carry maximum legal loads for the
roadway must be posted.
The vast majority of inspections are done by state employees or consultants working for the
states. FHWA bridge engineers do, at times, perform field reviews to assure that states are
complying with the bridge inspection requirements. FHWA also provides on-site engineering
expertise in the examination of the reasons for a catastrophic bridge failure. However, FHWA
bridge engineers have only limited time available for audits and other bridge oversight.
FHWA’s Emergency Relief Program
The Emergency Relief Program21 provides funding for bridges damaged in natural disasters or
that are subject to catastrophic failures from an outside source. The program provides funds for
emergency repairs immediately after the failure to restore essential traffic, as well as for longer-
term permanent repairs.
Emergency Relief is authorized at $100 million per year, nationwide. Funding beyond this
amount is commonly provided for in supplemental appropriations acts. In the case of most large

19 23 C.F.R. §650, subpart C.
20 A fracture-critical member is a steel member in tension, or with a tension element, whose failure would probably
cause a portion of or the entire bridge to collapse.
21 CRS Report R45298, Emergency Relief for Disaster-Damaged Roads and Public Transportation Systems, by Robert
S. Kirk and William J. Mallett.
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disasters, additional emergency relief funds are provided in an appropriations bill, usually a
supplemental appropriations bill.
The federal share of emergency repairs to restore essential travel during the first 180 days
following a disaster is 100%. Later repairs, as well as permanent repairs such as reconstruction or
replacement of a collapsed bridge, are reimbursed at the same federal share that would normally
apply to the federal-aid highway facility. Congress has sometimes legislatively raised the federal
share under the Emergency Relief Program to 100%. As is true with other FHWA programs, the
Emergency Relief Program is administered through state departments of transportation in close
coordination with FHWA’s field office in each state.
Issues for Congress
The large number of bridges classified as poor, together with some highly publicized incidents
involving highway bridges, such as the washout of a bridge on Interstate 10 in California in 2015
and the use restriction imposed on the Arlington Memorial Bridge in Washington, DC, has led to
warnings of an incipient crisis.22 FHWA data do not substantiate this assertion. For example, the
number of bridges classified as poor has consistently fallen over the past decade, totaling about
15,000 fewer bridges in poor condition in 2019 than in 2009.
The condition of roads, in particular urban roads, has not experienced the same degree of
improvement as the condition of bridges.23 This disparity raises the policy question of what
priority should go to bridge repairs as opposed to roadway repairs. In MAP-21, enacted in 2012,
Congress implicitly addressed this issue by giving states greater flexibility to use federal funding
for roads or for bridges, at their discretion. In doing so, Congress chose not to mandate any
specific level of spending on bridges. Instead, responsibility for determining the amount that
should be spent on bridges each year was assigned to the states.
A related issue is one of efficiency. Bridges classified as in poor condition are not in most cases
unsafe bridges, and an intensive effort to repair all bridges that are in poor condition could
quickly lead to spending on relatively low-priority projects that do not present major safety
problems. MAP-21 also required FHWA to develop performance measures in regard to bridges.
The effectiveness of implementation, and whether the measures fulfill the intent of Congress,
may be ongoing oversight issues.

Tolling of Non-tolled Bridges
Wider use of tolling could allow for more rapid improvement of major bridges. Heavily traveled
bridges can be attractive targets for conversion to toll facilities; many bridges have no convenient
alternatives, so drivers may find it difficult to avoid paying whatever toll is imposed. The revenue

22 See, for example, “Collapsed California Bridge Earned ‘A’ Rating Just Last Year,” USA Today, July 21, 2015,
http://www.usatoday.com/story/news/nation/2015/07/20/collapsed—10-bridge-given-rating-just-last-year/30428515/.;
“Memorial Bridge, symbol of U.S. strength, is corroded, partly shut down,” Washington Post, May 30, 2015, at
https://www.washingtonpost.com/local/trafficandcommuting/memorial-bridge-symbol-of-us-strength-is-corroded-
partly-shut-down/2015/05/28/bbe0e9b0-0582-11e5-a428-c984eb077d4e_story.html; American Road and
Transportation Builders Association, “2020 Bridge Report,” at https://artbabridgereport.org/.
23 See also U.S. Congressional Budget Office, Approaches to Make Federal Highway Spending More Productive,
February 2016, pp. 1-50, at https://www.cbo.gov/sites/default/files/114th-congress-2015-2016/reports/50150-
Federal_Highway_Spending-OneCol.pdf.
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stream provided by tolls can make bridge building and reconstruction an attractive investment for
private entities that are interested in participating in a public-private partnership. Tolling can also
help projects become eligible for a federal Transportation Infrastructure Finance and Innovation
Act (TIFIA) loan. Bridge tolls, however, are often very unpopular, and their acceptance varies
greatly from region to region. Some states have sought to make bridge tolls more acceptable
within a state by charging out-of-state users at a much higher rate than in-state residents, a
practice that may face legal challenges.24
Currently, any bridge on the federal-aid highway system, including Interstate Highway bridges,
may be converted to a toll facility if the conversion is related to the reconstruction or replacement
of the previously non-tolled bridge. 25 New bridges, including bridges on new segments of
Interstate Highways, may be tolled as well. Added lane capacity on a bridge may be tolled as long
as the number of free lanes remains the same. Any bridge owner (a state, public authority, or other
eligible entity) has the right to implement tolling, provided the facility is eligible to be tolled
under 23 U.S.C. Sections 129 or 166, or under federally authorized pilot toll programs. FHWA
does not regulate the toll rates users pay. Setting toll rates is the responsibility of the bridge owner
or operator. However, for toll roads operating under Sections 129 or 166, federal law does impose
restrictions on the use of toll revenues.
Tolling Bridges Between States
Establishing tolls on bridges that connect two states is generally done with the agreement of the
states on both ends of the bridge. This does not always have to be the case, as such bridges are not
always jointly owned. In the case of a bridge between two states that is owned by one of the
states, the bridge owner might be able to impose tolls unilaterally; if such a bridge is on the
Interstate Highway system, the state could impose tolls only through participation in the Value
Pricing Pilot Program.26 Congress might consider providing guidance on the process of imposing
tolls on bridges between two states.
Spending on Off-System Bridges
Historically, nearly all federal highway funding was restricted to roads and bridges on the federal-
aid highway system. The Surface Transportation Assistance Act of 1978 (P.L. 95-599) stipulated
that not less than 15% of a state’s bridge apportionments nor more than 35% be spent “off-
system,” that is, on relatively small bridges on roads that are not part of the 1.03 million-mile
federal-aid system.27 A minimum level of spending on off-system bridges has been required in
every highway authorization bill since 1978. Under current law, STBG funds equal to at least
15% of the amounts apportioned to a state for the Highway Bridge Program in FY2009 are to be
obligated for off-system bridge projects.

24 CRS Report R44910, Tolling U.S. Highways and Bridges, by Robert S. Kirk.
25 The exception to the reconstruction or replacement requirement would be to convert all or some of the bridge lanes to
a congestion pricing facility under the Value Pricing Pilot Program.
26 For example, Oregon is the owner of the I-5 Columbia River Bridge, which links Portland, OR, and Vancouver, WA.
It already has one of the 15 slots allowed under the Value Pricing Program, and has included the bridge in a broader
study of implementing value pricing in Portland. Ultimately, if the state of Oregon chooses to toll the bridge and
demonstrates that the I-5 tolling project fulfills value pricing objectives, FHWA would be asked to approve tolling as
part of the program. Oregon could then collect tolls on the bridge or near the water’s edge without the agreement of
Washington.
27 FHWA, “Public Road Length-2014(1): Miles by Ownership and Federal-aid Highways,” National Summary Table
HM-16, Highway Statistics 2018, August 30, 2019, at https://www.fhwa.dot.gov/policyinformation/statistics/2018/
hm16.cfm. The total public road length in the United States for 2018 was 4.2 million miles.
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Off-system bridges, by definition, are inherently local in nature. By eliminating the set-aside for
off-system bridges, Congress could enable states to spend more of their federal funds on bridges
that are more heavily used, but states would not be required to spend funds for that purpose
without additional legislation. However, 58.5% of bridges classified as in poor condition are on
local rural roads or minor rural collectors, which are off-system. The set-aside for off-system
projects has been strongly supported by predominantly rural states and by many county and
municipal governments.
Bridge Improvement Type
Of the funds both authorized and obligated for bridges in FY2018 from all FHWA sources, 3%
were obligated for new bridges, 57% were obligated for bridge replacement, 9% were for major
rehabilitation, and 31% were for minor bridge work. The 60% combined share obligated for both
new and replacement bridges was less than in the late 1990s, when it approached 70%. The share
of spending for major bridge rehabilitation has also fallen since the late 1990s. Meanwhile, four
times the proportion of federal funding went to minor bridge work in FY2018 as in the 1990s.28
The shift in spending of federal funds from large bridge construction projects to minor
rehabilitation projects could be due to the falling number of deficient bridges, but it also could
indicate that states are favoring less expensive projects and delaying some new bridges or bridge
replacements because of the higher cost of these projects. Examining the trends in spending by
improvement type could reveal state bridge priorities.
Federal Lands and Tribal Bridges
Funding for bridges owned by the federal government or by Indian tribes does not come from the
regularly apportioned programs discussed above. Funding is authorized separately, primarily from
two stand-alone programs: the Tribal Transportation Program29 and the Federal Lands
Transportation Program. The Tribal Transportation Program funds are under the control of the
tribes, in cooperation with the Department of the Interior and the Department of Transportation.
The Federal Lands Transportation Program funds are under the control of the federal land
management agencies, with assistance and oversight from the Department of Transportation. A
third program, the Federal Lands Access Program, funds facilities that provide access to federal
lands. The use of these funds in each state is determined by a state committee that includes
representatives of FHWA, the state department of transportation, and a political subdivision of the
state.
Compared to the core highway formula programs, these programs are small. Under the FAST Act,
an average of $485 million annually is available to the Tribal Transportation Program. The $355
million annual average Federal Lands Transportation program authorization is divided among the
National Park Service ($284 million), the Fish and Wildlife Service ($30 million), the U.S. Forest
Service ($17 million), and other federal land management agencies ($24 million). These funds
must cover both road and bridge needs as well as any public transportation funding. These
programs are paid for from the Highway Trust Fund.

28 FHWA, “Obligation of Federal Funds for Bridge Projects Underway by Improvement Type,” Highway Statistics,
various years, and Highway Statistics 2018, Table FA-10. Based on data from Table FA-10 for FY1996-FY1999,
obligation for minor bridge rehabilitation relative to total bridge obligations for the years was 6% for FY1996, 8% for
FY1997, 7% for FY1998, and just below 10% for FY1999.
29 CRS Report R44359, Highways and Highway Safety on Indian Lands, by William J. Mallett.
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Highway Bridge Conditions: Issues for Congress

The structure for funding bridges on federal and tribal land has given rise to some complications,
such as those relating to the ongoing rehabilitation of Arlington Memorial Bridge. The bridge is
owned by the National Park Service. Therefore, the work would logically be paid out of the Park
Service’s funding under the Federal Lands Transportation Program, but the cost is expected to be
$227 million, nearly as much as the Park Service receives each year for all highway needs. To
complete the project the Park Service is combining $107 million of its transportation and general
construction funds with a discretionary grant of $90 million from the Department of
Transportation’s Infrastructure for Rebuilding America (INFRA) program and a transfer of $30
million in federal highway formula funds from Virginia and the District of Columbia.30 The FAST
Act established the Nationally Significant Federal Lands and Tribal Projects Program (NSFLTP),
authorized at $100 million annually, to provide an extra source of funds for large projects on
federal or tribal lands, but this money is subject to appropriation each year. The NSFLTP has
received appropriations of $300 million for FY2018, $25 million for FY2019, and $70 million for
FY2020. Congress may wish to consider the adequacy of funding for large federal lands bridge
projects such as Arlington Memorial Bridge.
Oversight and Inspection Issues31
Risk-Based Approach to Federal Bridge Oversight
MAP-21 required that the National Bridge Inventory classify bridges according to serviceability,
safety, and essentiality for public use, and based on this classification assign each bridge a risk-
based priority for systematic preventive maintenance, replacement, or rehabilitation.32 FHWA has
chosen not to pursue a rule to implement these provisions (23 U.S.C. §144(b) (3) and (4)).
According to FHWA, after considering a variety of approaches to the required classification
system the agency determined that all the approaches “would conflict or compete with the current
Transportation Performance Management and Asset Management requirements.”33
However, the provisions remain a required part of current law regarding the National Bridge
Inventory, and the failure to pursue the provisions means there is effectively no national bridge
rating system. Congress may wish to revisit the MAP-21 bridge classification and risk-based
priority setting requirements.

30 Department of the Interior, “Under Budget & Ahead of Schedule: Secretary Zinke Announces Full Funding to Repair
Arlington Memorial Bridge,” press release, December 1, 2017, at https://www.doi.gov/pressreleases/under-budget-
ahead-schedule-secretary-zinke-announces-full-funding-repair-arlington.
31 See also FHWA, “Tables of Frequently Requested NBI Information,” at http://www.fhwa.dot.gov/bridge/britab.cfm.
32 Previously, a 0%-100% “sufficiency” (to be in service) rating was determined for each bridge. This rating alone,
however, did not determine which bridges were replaced or reconstructed. These ratings were used for many years
without being seen as in conflict with 23 U.S.C. §145. The sufficiency ratings are not used for the use of funds
provided in MAP-21 or the FAST Act.
33 Letter from Federal Highway Administration, Congressional Affairs Team, to Robert S. Kirk, Specialist in
Transportation Policy, June 3, 2020. In particular, FHWA found that the requirement that each highway bridge to be
assigned a priority for preventive maintenance, replacement, or rehabilitation, could be contradictory to the
requirements of 23 U.S.C.§119(e) which require states to develop risk-based asset management plans and use the
results of those plans to prioritize their projects under NHPP. FHWA also expressed concerns that implementation was
contradictory to “the State-administered nature of the Federal-aid Highway Program as provided by 23 U.S.C.§145.
FHWA does not have the authority to dictate what projects States pursue and fund, so a priority system set by FHWA
would not be meaningful.”
Congressional Research Service

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Highway Bridge Conditions: Issues for Congress

Inspection Auditing
FHWA could be directed to take a more active role in ensuring that inspections performed by the
states or their contractors are done in conformance with the NBIS. This step might involve a
requirement for more on-site field reviews of state inspections or increased review or inspection
paperwork. At some division offices FHWA might have to hire more engineers and support
personnel to carry out the increased workload; at others FHWA might be able to dedicate more of
its existing resources to oversight of the inspection program.
Bridge Postings and Closures
A bridge classified as in poor condition is not necessarily unsafe, but may require the posting of a
vehicle weight restriction. When officials determine that a bridge is unsafe, they are to close it to
traffic immediately. The actual closing of a bridge is usually done by the state, but in some states
closures are under the authority of county commissioners. The recent failure of local officials in
Mississippi to close unsafe bridges until the state was threatened with the withholding of federal
funds suggests that unsafe bridge closures do not always happen immediately.34
Each year Congress is asked to approve exceptions from federal weight and length rules for
trucks. Increased truck weights can put stress on bridge structures. Congress might consider a
process mandating studies of the proposed weight limit exemptions on bridges to lessen the
potential for future problems that could result in weight restrictions or closures.
Inspector Training and Personnel Qualifications
Current law includes requirements for the establishment of minimum inspection standards and an
annual review of state compliance with the standards established in MAP-21. Under the act, the
Secretary of Transportation is to update the NBIS, including those governing the methodology,
training, and qualifications of inspectors. The Notice of Proposed Rulemaking was issued on
November 12, 2019, and the extended closing date for comments was March 13, 2020.35 Once the
final rule is published, Congress may wish to oversee implementation of these provisions and to
monitor their effectiveness.

34 Cameron McWhirter, “Mississippi Gov. Bryant Orders More Than 100 Bridges Closed,” Wall Street Journal, April
12, 2018, at https://www.wsj.com/articles/mississippi-gov-bryant-orders-more-than-100-bridges-closed-1523541600.
35 FHWA, National Bridge Inspection Standards (MAP-21), Notice of Proposed Rulemaking, Federal Register,
November 12, 2019, at https://www.federalregister.gov/documents/2019/11/12/2019-23929/national-bridge-inspection-
standards, and the extension of the comment period at https://www.federalregister.gov/documents/2020/01/13/2020-
00315/national-bridge-inspection-standards.
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Highway Bridge Conditions: Issues for Congress

Appendix A. Bridge Condition by State and
Territory
(Data as of December 31, 2019)
All
Condition Rating (number)
Condition Rating (percent)
Bridges
State
(number)
Good
Fair
Poor
Good
Fair
Poor
Alabama
16,162
6,740
8,768
654
41.7
54.3
4.0
Alaska
1,595
706
744
145
44.3
46.6
9.1
Arizona
8,320
5,098
3,085
137
61.3
37.1
1.6
Arkansas
12,902
6,598
5,678
626
51.1
44.0
4.9
California
25,771
13,707
10,267
1,797
53.2
39.8
7.0
Colorado
8,785
3,550
4,769
466
40.4
54.3
5.3
Connecticut
4,336
1,256
2,805
275
29.0
64.7
6.3
Delaware
879
248
603
28
28.2
68.6
3.2
District of
244
60
174
10
24.6
71.3
4.1
Columbia
Florida
12,518
8,279
3,878
361
66.1
31.0
2.9
Georgia
14,940
6,796
7,703
441
45.5
51.6
3.0
Hawaii
1,138
297
761
80
26.1
66.9
7.0
Idaho
4,493
1,282
2,916
295
28.5
64.9
6.6
Il inois
26,825
13,084
11,334
2,407
48.8
42.3
9.0
Indiana
19,284
7,892
10,226
1,166
40.9
53.0
6.0
Iowa
24,043
9,319
10,149
4,575
38.8
42.2
19.0
Kansas
24,934
13,468
10,186
1,280
54.0
40.9
5.1
Kentucky
14,394
4,908
8,444
1,042
34.1
58.7
7.2
Louisiana
12,884
6,244
4,939
1,701
48.5
38.3
13.2
Maine
2,461
748
1,399
314
30.4
56.8
12.8
Maryland
5,402
1,783
3,346
273
33.0
61.9
5.1
Massachusetts
5,233
1,371
3,393
469
26.2
64.8
9.0
Michigan
11,244
4,304
5,723
1,217
38.3
50.9
10.8
Minnesota
13,346
8,085
4,630
631
60.6
34.7
4.7
Mississippi
17,019
10,682
4,853
1,484
62.8
28.5
8.7
Missouri
24,494
10,228
12,119
2,147
41.8
49.5
8.8
Montana
5,278
1,602
3,296
380
30.4
62.4
7.2
Nebraska
15,332
7,996
5,980
1,356
52.2
39.0
8.8
Nevada
2,029
1,009
994
26
49.7
49.0
1.3
New Hampshire
2,502
1,323
966
213
52.9
38.6
8.5
Congressional Research Service

13

Highway Bridge Conditions: Issues for Congress

All
Condition Rating (number)
Condition Rating (percent)
Bridges
State
(number)
Good
Fair
Poor
Good
Fair
Poor
New Jersey
6,786
1,825
4,432
529
26.9
65.3
7.8
New Mexico
4,013
1,516
2,277
220
37.8
56.7
5.5
New York
17,540
6,348
9,447
1,745
36.2
53.9
9.9
North Carolina
18,407
7,087
9,606
1,714
38.5
52.2
9.3
North Dakota
4,329
2,352
1,515
462
54.3
35.0
10.7
Ohio
27,167
16,101
9,609
1,457
59.3
35.4
5.4
Oklahoma
23,138
10,174
10,612
2,352
44.0
45.9
10.2
Oregon
8,211
2,850
4,935
426
34.7
60.1
5.2
Pennsylvania
22,911
7,330
12,080
3,501
32.0
52.7
15.3
Rhode Island
779
138
467
174
17.7
59.9
22.3
South Carolina
9,419
4,130
4,494
795
43.8
47.7
8.4
South Dakota
5,821
1,940
2,890
991
33.3
49.6
17.0
Tennessee
20,226
8,777
10,562
887
43.4
52.2
4.4
Texas
54,432
27,958
25,749
725
51.4
47.3
1.3
Utah
3,063
1,419
1,578
66
46.3
51.5
2.2
Vermont
2,818
1,494
1,256
68
53.0
44.6
2.4
Virginia
13,933
4,670
8,656
607
33.5
62.1
4.4
Washington
8,300
4,307
3,609
384
51.9
43.5
4.6
West Virginia
7,291
1,861
3,899
1,531
25.5
53.5
21.0
Wisconsin
14,249
7,271
5,952
1,026
51.0
41.8
7.2
Wyoming
3,114
943
1,956
215
30.3
62.8
6.9
Guam
10
2
6
2
20.0
60.0
20.0
Puerto Rico
2,315
422
1,609
284
18.2
69.5
12.3
U.S. Virgin Islands
24
3
15
6
12.5
62.5
25.0
Total
617,083
279,581
291,339
46,163
45.3
47.2
7.5
Source: Federal Highway Administration, National Bridge Inventory, “Bridge Condition by Functional
Classification, 2019,” https://www.fhwa.dot.gov/bridge/fc.cfm.

Congressional Research Service

14

Appendix B. Bridge Obligations by Program: FY2012-FY2019 (current dollars)
Program
FY2012
FY2013
FY2014
FY2015
FY2016
FY2017
FY2018
FY2019
Interstate Maintenance
755,656,556
129,051,722
40,227,615
11,385,907
2,406,944
2,305,999
8,908,364
2,240,105
National Highway System
680,253,396
88,777,186
55,653,947
55,928,169
37,274,844
29,941,503
26,125,570
20,040,402
Surface Transportation
Program
558,073,243
1,662,455,267
2,211,511,901
2,254,453,670
2,409,636,146
2,107,910,876
2,566,044,582
2,515,966,628
National Highway
Performance Program
—
3,018,008,912
3,673,113,345
3,638,484,037
3,910,107,620
3,936,751,913
3,789,511,563
4,032,500,809
National Highway Freight
Program
—
—
—
—
237,121,333
106,864,872
260,926,616
155,729,020
Transportation Alternatives
—
138,881
4,620,618
2,368,351
6,332,735
3,967,287
3,562,061
7,840,507
Bridge Programs
3,575,482,507
960,648,620
220,620,109
243.314,396
79,924,642
71,802,855
43,968,419
2,091,860
Congestion Mitigation and
Air Quality
(10,213,853)
72,343,225
41,677,322
62,542,855
38,121,580
44,430,292
31,197,678
30,500,730
Appalachian Development
Highway System
5,436,959
24,767,784
16,374,183
51,015,156
158,589,439
63,980,429
(586,007)
10,843,215
High Priority Projects
61,045,589
—
31,470,461
10,125,976
17,908,671
15,770,437
13,463,004
6,370,325
Minimum Guarantee—
TEA-21
12,053,469
9,919,033
2,720,538
10,404,647
10,711287
1,828,744
(266,006)
(2,089,107)
Equity Bonus Exempt Lim
59,268,059
451,407,959
220,471,325
211,958,856
8,778,554
16,978,609
4,605,487
7,038,169
Coordinated Border
Infrastructure Program
10,461,126
3,049,907
84,377,062
2,569,474
(3,142,320)
6,169,284
(232,028)
(1,000,000)
Safe Routes to School
—
—
__
694,649
—
—
(24,133)
—
Planning and Research
(200,000)
—
__
—
—
—
130,043
151,500
All Others
306,635,541
63,018,956
200,128,997
248,261,223
181,235,160
257,267,156
344,279,171
576,427,938
Total
6,013,952,592
6,483,587,452
6,802,967,421
6,803,507,367
7,095,006,638
6,665,970,255
7,091,614,385
7,364,652,101
Source: Federal Highway Administration (FHWA).
Note: Displays funds from the Fixing America’s Surface Transportation Act (FAST Act; P.L. 114-94), as well as ongoing obligation of funds from earlier authorization acts.
CRS-15

Highway Bridge Conditions: Issues for Congress

Author Information

Robert S. Kirk
William J. Mallett
Specialist in Transportation Policy
Specialist in Transportation Policy

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