United States Government Accountability Office

GAO Testimony 

Before the Committee on Environment 

and Public Works, U.S. Senate 

HIGHWAY BRIDGE 

PROGRAM 

Clearer Goals and 

Performance Measures 

Needed for a More Focused 

and Sustainable Program 

Statement of Katherine Siggerud, Managing Director 

Physical Infrastructure Issues 

For Release on Delivery

Expected at 10:00 a.m. EDT 

Wednesday, September 10, 2008

 

GAO-08-1127T 
What GAO Found

United States Government Accountability Office

Why GAO Did This Study

Highlights

Accountability Integrity Reliability

September 2008

HIGHWAY BRIDGE PROGRAM

Clearer Goals and Performance Measures Needed for 

a More Focused and Sustainable Program 

Highlights of GAO-08-1127T, a testimony 

before the Committee on Environment and 

Public Works, U.S. Senate 

The August 1, 2007, collapse of a

Minnesota bridge raised 

nationwide questions about bridge 

safety and the Department of 

Transportation’s (DOT) 

prioritization of bridge resources.

The Highway Bridge Program 

(HBP), the primary source of 

federal funding for bridges, 

provided over $4 billion to states in 

fiscal year 2007. This testimony, 

based on a report GAO is releasing 

today, addresses (1) how states use

HBP funds and select bridge 

projects for funding, (2) what data 

indicate about bridge conditions 

and the HBP’s impact, and (3) the 

extent to which the HBP aligns 

with principles we developed,

based on our prior work and 

federal laws and regulations, for reexamining surface transportation

programs. The testimony also 

discusses the implications of our 

work for related sections of

proposed legislation under review

by this committee, the National 

Highway Bridge Reconstruction

and Inspection Act of 2008

(S.3338). 

What GAO Recommends

In the report released today, GAO 

made recommendations to improve 

the focus, performance, and 

sustainability of the HBP and DOT 

officials said they generally agreed

with those recommendations. The 

DOT officials also commented that

GAO’s principles had broader 

applicability than the HBP, noting

that they had incorporated the 

principles into the department’s 

recent proposal for reforming 

surface transportation programs. 

As context for understanding GAO’s findings on the HBP, based on 

information gathered during bridge inspections that are generally conducted 

every 2 years, the HBP classifies bridge conditions as deficient or not; assigns 

each bridge a sufficiency rating reflecting its structural adequacy, safety, 

serviceability, and relative importance for public use; and uses that 

information to distribute funding to states to improve bridges. Deficient 

bridges include those that are structurally deficient, with one or more 

components in poor condition, and those that are functionally obsolete, with a 

poor configuration or design that may no longer be adequate for the traffic 

they serve. 

Use of HBP funds and project selection: The HBP affords states 

discretion to use HBP funds and select bridge projects in a variety of ways. 

Some states are focused on reducing their number of deficient bridges, while 

other states are pursuing different bridge priorities. For example, California 

has focused on seismically retrofitting bridges, a safety concern for that state. 

Furthermore, some states have developed tools and approaches for selecting 

bridge projects that go beyond those required by the HBP—such as bridge 

management systems and state-specific bridge condition rating systems. 

Bridge conditions and impact of HBP: Bridge conditions, as measured by 

the number of deficient bridges and average sufficiency rating of all bridges, 

improved from 1998 through 2007. However, the impact of the HBP on that 

improvement is difficult to determine because (1) the program provides only a 

share of what states spend on bridges and there are no comprehensive data

for state and local spending on bridges and (2) HBP funds can, in some cases, 

be used for a variety of bridge projects without regard to a bridge’s deficiency 

status or sufficiency rating. 

Alignment of HBP with GAO principles: The HBP does not fully align 

with GAO’s principles in that the program lacks focus, performance measures, 

and sustainability. For example, the program’s statutory goals are not focused 

on a clearly identified federal interest, but rather have expanded from 

improving deficient bridges to supporting seismic retrofitting, preventive 

maintenance, and many other projects, thus expanding the federal interest to 

potentially include almost any bridge in the country. In addition, the program 

lacks measures linking funding to performance and is not sustainable, given 

the anticipated deterioration of the nation’s bridges and the declining 

purchasing power of funding currently available for bridge maintenance, 

rehabilitation, and replacement. 

The results of our work are generally consistent with provisions of S.3338 that 

call for a risk-based prioritization process for selecting bridge projects, 5-year

performance plans, and bridge management systems. Our work does raise 

some questions about the legislation’s focus on all deficient bridges because 

some deficient bridges do not need immediate repairs to carry traffic safely. 

To view the full product, including the scope 

and methodology, click on GAO-08-1127T. 

For more information, contact Katherine 

Siggerud at (202) 512-2834 or 

siggerudk@gao.gov. 
Chairman Boxer and Members of the Committee: 

I am pleased to be here today to participate in this hearing on federal 

efforts to address the condition of our nation’s bridges. The August 1, 

2007, collapse of the I-35W bridge in Minneapolis, Minnesota, raised 

questions about the condition and safety of our nation’s bridges and about 

the federal government’s ability to prioritize resources for bridges. Bridges 

are critical elements of the nation’s transportation network, supporting 

commerce, economic vitality, and personal mobility. The Federal Highway 

Administration’s (FHWA) Highway Bridge Program (HBP), the primary 

source of federal funding for bridges, provided over $4 billion to states in 

fiscal year 2007. This program, which provides funding assistance to states 

to improve the condition of their bridges, specifies a large variety of 

activities that states may undertake with program funds.1

Since the Minnesota bridge collapse, there have been calls for increased 

federal investment in bridge infrastructure. In July 2008, the House of 

Representatives passed H.R. 3999, the National Highway Bridge 

Reconstruction and Inspection Act of 2008, authorizing an additional $1

billion for fiscal year 20092

 from the U.S Treasury’s general fund3 to 

address bridges, and shortly thereafter, a Senate companion bill to that 

legislation (S. 3338) was introduced in this committee. These calls for 

increased investment in bridge infrastructure coincide with strains on 

traditional funding for infrastructure projects because the Highway Trust 

Fund, which funds the HBP and other highway programs, is projected to 

incur significant deficits in the years ahead. We have also recently called 

for a fundamental re-examination of surface transportation programs and 

commitments to address emerging needs by eliminating outdated or 

 1

States may use HBP funds for seven types of bridge-related activities, including 

replacement, rehabilitation, painting, seismic retrofitting, systematic preventive 

maintenance, installation of scour countermeasures (to address the effects of sediment

erosion around bridge piers and abutments), and anti-icing or deicing activities. 

2

The $1 billion represents an amount in addition to what was authorized for 2009 for HBP 

and other related programs in the most recent surface transportation authorizing 

legislation enacted in 2005. 

3

The federal budget consists of several types of funds, including the general fund, trust 

funds (such as the Highway Trust Fund), and others. General funds are federal revenues

not designated for specific purposes and they are used to fund, among other things, 

national defense, interest on the public debt, operating expenses of most federal agencies,

and some entitlements and grants to state and local governments. 

Page 1 GAO-08-1127T 
ineffective programs, more sharply defining the federal role in relation to

state and local roles, and modernizing relevant programs.4

Given these concerns, my testimony today addresses (1) how states use 

their HBP funds and select specific bridge projects for funding, (2) what 

available data indicate about national trends in bridge conditions and the 

impact of the HBP, and (3) the extent to which the HBP aligns with 

principles we developed to guide the re-examination of surface 

transportation programs. Additionally, I am providing a perspective on 

related sections of the proposed bridge legislation under review by this 

committee (S.3338). My testimony is based on a report that we are 

releasing today.5

To determine how state transportation departments use their HBP funds 

and select specific bridge projects for funding, we visited six states—

California, Missouri, New York, Pennsylvania, Texas, and Washington—

where we interviewed federal, state, and local transportation officials, 

including bridge owners and inspectors. We selected these states because

they have relatively high levels of federal bridge funding, large bridge 

inventories, and large inventories of bridges eligible for replacement or 

rehabilitation. To determine what available data indicate about trends in 

the condition of the nation’s bridges and the impact of the HBP, we 

analyzed data in FHWA’s National Bridge Inventory (NBI)—the primary 

source of information on the nation’s bridges—which contains

information on each bridge’s location, size, age, condition, inspection 

dates, and other information; reviewed relevant legislation and program 

documents; and interviewed federal, state, and local transportation 

officials. To determine the extent to which the HBP aligns with our 

principles for re-examining federal programs, we compared HBP practices

to the four key principles we identified in our previous work, including 

identifying clear federal goals and roles, incorporating performance and 

accountability into funding decisions, using best tools and approaches, 

 4

GAO, Surface Transportation: Restructured Federal Approach Needed for More Focused, 

Performance-Based, and Sustainable Programs, GAO-08-400 (Washington, D.C.: Mar. 6,

2008). 

5

GAO, Highway Bridge Program: Clearer Goals and Performance Measures Needed for a

More Focused and Sustainable Program, GAO-08-1043 (Washington, D.C.: Sept. 10, 2008). 

Page 2 GAO-08-1127T 
and ensuring fiscal sustainability.6

 We conducted our review from October 

2007 through September 2008 in accordance with generally accepted

government auditing standards. Those standards require that we plan and

perform the audit to obtain sufficient, appropriate evidence to provide a 

reasonable basis for our findings and conclusions based on our audit 

objectives. We believe that the evidence obtained meets these standards. 

The HBP affords states discretion to use HBP funds and select bridge 

projects in a variety of ways. Some states are focused on reducing their 

number of deficient bridges,7

 while other states are pursuing different 

bridge priorities. For example, California has focused on seismically 

retrofitting bridges, a safety concern for that state. In addition, some states 

transfer a portion of their HBP funds to other transportation priorities as 

allowed by the program, though some of these transferred HBP funds may 

still be spent on bridges, as well as other work on roadways. Furthermore, 

some states have also developed tools and approaches for selecting 

potential bridge projects that go beyond those required by the HBP—such 

as bridge management systems, highly detailed inspections of bridge 

elements, state-specific bridge condition ratings, and various prioritization 

processes—to help them better gauge bridge conditions and further 

inform their selection of bridge projects for funding. For example, all six 

states we visited have adopted, or are considering, some form of bridge 

management system to help them manage their bridge assets and more 

efficiently allocate their HBP and other bridge funds among competing 

bridge priorities. 

Summary 

 6

These principles were developed in our earlier work on 21st century challenges and were

based on our institutional knowledge, our extensive program evaluation and performance

assessment work for the Congress, and federal laws and regulations. See GAO, 21st 

Century Challenges: Re-examining the Base of the Federal Government, GAO-05-325SP 

(Washington, D.C.: Feb. 1, 2005) and GAO, High Risk Series: An Update, GAO-07-310

(Washington, D.C.: Jan. 31, 2007). 

7

The HBP classifies bridge conditions as deficient or not. Deficient bridges include those 

that are structurally deficient, with one or more components in poor condition, and those 

that are functionally obsolete, with a poor configuration or design that may no longer be 

adequate for the traffic they serve. 

Page 3 GAO-08-1127T 
Bridge conditions, as measured by the number of deficient bridges and the 

average sufficiency rating of all bridges in the NBI,8

 improved from 1998 

through 2007. For example, the number of structurally deficient bridges 

decreased by 22 percent from 1998 through 2007, from 93,118 to 73,519

bridges nationwide. The average sufficiency rating of all bridges also 

improved slightly during that period, with the improvements most notable 

in bridges owned by local agencies and on rural routes. However, the 

impact of the HBP on that improvement is difficult to determine, in part, 

because (1) the program provides only a share of what state and local 

governments spend on bridges and there are no comprehensive data for 

state and local spending on bridges and (2) HBP funds can, in some cases, 

be used for a variety of bridge projects without regard to a bridge’s 

deficiency status or sufficiency rating. 

The HBP does not fully align with the re-examination principles that we 

previously identified in our work in that the program lacks focus on 

federal or national interests, performance measures, and sustainability. 

For example, the program’s goals—which are established in federal 

statute9

—are not focused on a clearly identified federal interest. Rather, 

the goals have expanded from improving deficient bridges to supporting 

seismic retrofitting, preventive maintenance, and many other projects, 

thus expanding the federal interest to potentially include almost any 

bridge in the country. In addition, the HBP lacks measures linking funding 

to performance, and it is not sustainable, given the anticipated 

deterioration of the nation’s bridges and the declining purchasing power of 

funding currently available for bridge maintenance, rehabilitation, and 

replacement. Once the federal interest in bridges is clearly defined, 

policymakers can clarify the goals for federal involvement and align the 

program to achieve those goals. HBP sustainability may also be improved 

by identifying and developing performance measures and re-examining 

funding mechanisms. In our report released today, we recommend that 

DOT work with Congress to improve the focus, performance, and 

sustainability of the HBP by defining specific national goals, establishing 

and implementing performance measures, evaluating best tools and 

practices, and evaluating HBP’s funding mechanisms to better support a 

targeted and sustainable program. In commenting on a draft of the report, 

 8

In addition to classifying bridges as deficient or not, the HBP also assigns each bridge a

sufficiency rating reflecting its structural adequacy, safety, serviceability, and relative 

importance, and it uses this information in distributing HBP funding to the states. 

9

See 23 U.S.C. § 144. 

Page 4 GAO-08-1127T 
DOT officials said that they generally agreed with our findings and 

recommendations, and they provided technical clarifications which we 

incorporated in the report and this testimony, as appropriate. DOT 

officials also commented that our re-examination principles had broader 

applicability than the HBP—noting that they had incorporated the 

principles into the Department’s recent proposal for reforming surface 

transportation programs. 

Finally, our work on the HBP has implications for several provisions of the 

proposed legislation under review by this committee, the National 

Highway Bridge Reconstruction and Inspection Act of 2008 (S.3338). In 

particular, the results of our work are consistent with the overall 

provisions calling for the establishment of a risk-based prioritization 

process for selecting bridge projects, 5-year performance plans, and bridge 

management systems. Our work does raise some questions about the 

scope of these activities, particularly the legislation’s focus on all deficient 

bridges, because all deficient bridges are not necessarily unsafe, according 

to many of the state transportation officials we interviewed. 

Bridge safety first emerged as a high-priority issue in the United States in 

the 1960s, following the collapse of the Silver Bridge between Ohio and 

West Virginia, which killed 46 people. That collapse prompted national 

concerns about bridge conditions and safety and highlighted the need to 

repair and replace bridges before they collapse. Congress responded by 

establishing two major federal bridge programs: (1) the National Bridge 

Inspection Program (NBIP) to ensure periodic safety inspection of bridges 

and (2) what is now known as the HBP to provide a funding mechanism to 

assist states in replacing and rehabilitating bridges. Both of these 

programs generally define applicable bridges as publicly owned, over 20 

feet in length, and located on public roads. Although the NBIP and HBP 

are separate programs, they are linked by the data collected through 

bridge inspections. For example, bridge information gathered through 

NBIP inspections is one factor used to determine the amount of HBP 

funding apportioned to states. 

Background 

The NBIP establishes federal standards, known as the National Bridge 

Inspection Standards, and program requirements for the proper safety 

inspection and evaluation of bridges. These standards establish by whom, 

with what frequency, and how bridge inspections are to be completed. For 

example, state departments of transportation (DOTs) carry out the federallevel policies, procedures, and requirements for inventory, inspection, 

bridge load ratings, quality assurance, and reports. Routine bridge 

Page 5 GAO-08-1127T 
inspections are generally conducted every 2 years, but with FHWA 

approval, the inspection interval may be extended to 4 years on certain 

bridges. Bridges may be inspected more often than every 2 years, when 

past inspection findings justify an increased inspection frequency. Bridge 

inspectors must record bridge data, including bridge conditions, during the 

inspection and report that information to the NBI, maintained by FHWA 

headquarters. 

Based on information gathered during bridge inspections and reported to

the NBI, the HBP classifies bridge conditions as deficient or not; assigns 

each bridge a sufficiency rating reflecting its structural adequacy, safety, 

serviceability, and relative importance; and uses that information to 

provide funding for states to improve bridges. Deficient bridges include

those that are structurally deficient, with one or more components in poor 

condition, and those that are functionally obsolete, with a poor 

configuration or design that may no longer be adequate for the traffic they

serve. FHWA uses information in the NBI to annually apportion HBP funds 

to the states. While each state’s HBP apportionment amount is largely 

determined by bridge conditions and bridges generally must be below a 

certain condition threshold to qualify for HBP funding, other bridges are 

also eligible for HBP funds because states may use the funds for a broad 

array of other purposes, such as bridge preventive maintenance projects.

All bridges are grouped into one of two general categories: Federal-aid 

highway bridges and bridges not on Federal-aid highways. The NBIP and

the HBP generally apply to both categories of bridges located on public 

roads.10 Federal-aid highway bridges are generally located on the National 

Highway System, a 160,000–mile network that carries over 40 percent of 

the nation’s highway traffic.11 Non-Federal-aid highway bridges are 

generally located on local or rural roads that carry lower volumes of traffic 

than state-owned bridges. 

 10The NBIP standards do not apply to pedestrian or railroad bridges, bridges on private 

roads, or tunnels. FHWA encourages states to require private organizations to inspect

privately owned bridges according to those standards. States are not responsible for the

inspection of bridges owned by federal agencies. 

11The National Highway System (NHS) is made up of five components, including (1) the

Interstate System, (2) selected other principal arterials, (3) the Strategic Highway Network, 

(4) Major Strategic Highway Network connectors, and (5) intermodal connectors that 

provide access between major intermodal passenger and freight facilities and other NHS 

components. 

Page 6 GAO-08-1127T 
The HBP affords state DOTs discretion in determining how to use their 

HBP funds, and as a result, states use HBP funds and select bridge 

projects in a variety of ways. The HBP gives states three key flexibilities in

determining how to use their HBP resources. First, the HBP has evolved to

allow states to use program funds not only for bridge replacement and 

rehabilitation, but also for a broad array of purposes—including painting, 

seismic retrofitting, systematic preventive maintenance, installation of 

scour countermeasures (to address the effects of sediment erosion around 

bridge piers and abutments), and anti-icing or deicing applications—

regardless of the bridge’s condition. In addition, FHWA has determined 

that the costs for personnel and equipment used in bridge inspections and 

for bridge management systems are consistent with the purpose of the 

HBP and therefore are also eligible uses for HBP funds. Thus, states have 

the flexibility to use HBP funds on bridge projects that may not 

immediately reduce their inventory of deficient bridges. Secondly, states 

have flexibility in determining how to split HBP resources between state 

and locally owned bridges. Aside from a requirement to distribute funds 

equitably, the only HBP requirement applicable to states’ allocation of 

program funds is that states must spend a minimum (15 percent) on nonFederal-aid highway bridges. Third, states may also spend program funds 

on other, nonbridge, transportation priorities by transferring up to 50 

percent of their annual HBP funding to other core Federal-aid highway 

programs,12 though a penalty is invoked by reducing the state’s HBP funds 

in the succeeding year by the amount transferred. Many states have taken

advantage of this provision over the years and transferred some of their 

HBP funding to other programs, although FHWA officials pointed out that 

some of the transferred HBP funds may still be spent on bridges and funds 

from other Federal-aid highway programs may also be spent on bridges. 

FHWA data show that significant funds have flowed toward bridges from 

other programs which, from a national perspective, exceed outflows from 

the HBP. Finally, planning for how HBP funds are spent is generally under 

the control of state DOTs; once states select bridge projects, they may 

apply to FHWA for the federal share of the costs, which is generally 80

percent of the project cost.13

State DOTs Exercise 

Discretion in 

Determining How to 

Use HBP Funds and 

Select Bridge Projects 

for Funding 

 12The majority of Federal-aid highway infrastructure funding is distributed through seven

major programs, often referred to as core highway programs. These programs are the

National Highway System Program, Surface Transportation Program, Interstate 

Maintenance Program, HBP, Congestion Mitigation and Air Quality Improvement Program, 

Highway Safety Improvement Program, and the Equity Bonus Program. 

13The federal share for bridge projects on the Interstate System is 90 percent. 

Page 7 GAO-08-1127T 
In part due to these flexibilities, state DOTs we visited have established a 

range of priorities for their HBP funds—from reducing the number of their 

deficient bridges to seismically retrofitting their bridges—and some opted 

to transfer their HBP funds to fund other transportation priorities. 

Although the key purpose of the HBP is to enable states to improve the 

condition of their deficient bridges, some state transportation officials we 

interviewed explained that they do not focus on reducing their inventories 

of deficient bridges for several reasons: 

• Deficient bridges are not necessarily unsafe. Many state transportation 

officials we interviewed told us that some of the deficient bridges in their 

states are in at least reasonably good condition and are safe. In addition, 

FHWA reported in 2007 that classifying a bridge as deficient does not 

immediately imply that it is likely to collapse or that it is unsafe.14

According to the FHWA report, if proper vehicle weight restrictions are 

posted and enforced, deficient bridges can continue to serve most traffic 

conditions. FHWA requires that bridge owners close to traffic any bridges 

that they determine to be unsafe. 

• The HBP apportionment formula may create a disincentive to improve 

deficient bridges. Many federal and state officials we met with noted this 

potential disincentive that occurs because reducing the number and deck 

area of deficient bridges reduces a state’s HBP funding eligibility.15 

• Some deficient bridge projects can be cost-prohibitive. Some state 

officials explained that certain large-scale bridge projects—often the most 

traveled, urban bridges on interstate corridors—are too expensive to be 

implemented with HBP funds alone, especially costly “mega” projects that 

have an estimated total cost greater than $500 million. 

State DOTs use a variety of criteria, tools, and methods to select among 

potential bridge projects. Officials in the six states we visited use criteria 

such as bridge condition ratings, average daily traffic over bridges, local 

transportation priorities, or funding availability when prioritizing and 

selecting among potential bridge projects. Some states have also 

 14DOT, 2006 Status of the Nation’s Highways, Bridges, and Transit: Conditions and 

Performance (Washington, D.C.: Jan. 22, 2007). 

15FHWA apportions, or divides, the annually authorized HBP funds among the states

according to a statutory apportionment process that considers a number of factors, 

including a state’s total deficient bridge deck area. Therefore, reducing the number and 

total deck area of deficient bridges reduces a state’s HBP funding eligibility. 

Page 8 GAO-08-1127T 
developed tools and approaches beyond those required by the HBP—such 

as bridge management systems, element-level inspections, state-specific 

condition ratings, and various prioritization approaches—to help them 

gauge bridge conditions and further inform their selection of bridge 

projects for funding. For example, all of the states we visited have 

adopted, or are considering, some form of bridge management system for 

gathering and analyzing bridge data to help manage their bridge assets and 

more efficiently allocate limited HBP resources among competing bridge

priorities. States use these systems to predict future bridge conditions, 

estimate bridge maintenance and improvement needs, determine optimal 

policies for rehabilitation and replacement, and recommend projects and 

schedules within budget and policy constraints. FHWA has actively 

encouraged, but has not required, states to use bridge management 

systems, in part, by providing state transportation officials with relevant 

training and technical support.16 In addition, all of the states we visited 

required bridge inspectors to gather more detailed “element-level” bridge

condition data, thereby exceeding the federal inspection requirements that 

require inspection of only the three major bridge components 

(superstructure, substructure, and deck).17 Furthermore, some state DOTs 

use their own bridge rating systems to better gauge bridge conditions and

to inform their selection of bridge projects for funding. For example, the 

New York State DOT uses its own condition rating scale, which is based 

on an assessment of 47 individual bridge elements, to prioritize bridge 

projects. Finally, state DOTs use different methods to prioritize and select 

bridge projects for funding. Whereas some states we visited had highly 

centralized prioritization processes, others allowed the process to vary 

across the state. 

 16There is currently no federal requirement that states use a bridge management system. 

The Intermodal Surface Transportation Efficiency Act of 1991 introduced a requirement

that states implement bridge management systems by December 1993, but this requirement 

was repealed by the National Highway System Designation Act of 1995. 

17The superstructure is the portion of a bridge’s structure that spans the obstacle the bridge 

is intended to cross (e.g., a waterway). The substructure consists of all parts that support

the superstructure. 

Page 9 GAO-08-1127T 
Bridge conditions, as measured by the number of deficient bridges and 

average sufficiency rating, improved from 1998 through 2007. According to

NBI data, the total number of deficient bridges—including both 

structurally deficient and functionally obsolete bridges—has decreased 

over the last 10 years, even as the total number of bridges has increased. 

From 1998 through 2007, the number of deficient bridges declined by 

nearly 12 percent, from 172,683 to 152,317, even with the addition of more 

than 16,000 new bridges to the NBI (see fig. 1). 

Figure 1: Trends in Numbers of Bridges and Deficient Bridges, 1998 through 2007 

Note: Deficient bridges include both structurally deficient and functionally obsolete bridges. 

The decline in the overall number of deficient bridges over the past decade

reflects a reduction in the number of structurally deficient bridges. From 

1998 through 2007, the number of structurally deficient bridges decreased 

by 22 percent, from 93,118 to 72,519 (see fig. 2). During that same period, 

the number of functionally obsolete bridges increased slightly from 79,565 

to 79,798, an increase of 233 bridges. The reduction in the number of 

structurally deficient bridges, rather than functionally obsolete bridges, 

over this time period may reflect bridge owners’ efforts to address the 

deterioration or damage that are characteristic of structurally deficient 

bridges. Although reducing or eliminating structurally deficient bridges 

may not always be a state’s highest priority, structurally deficient bridges 

often require maintenance and repair to remain in service. By contrast, 

functionally obsolete bridges do not necessarily require repair to remain in 

service and, therefore, are unlikely to be transportation officials’ top 

priority for rehabilitation or replacement. 

Available Data 

Indicate That the 

Overall Condition of 

the Nation’s Bridges 

Has Improved, but the 

Impact of the HBP Is 

Difficult to Determine 

0

100

200

300

400

500

600

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Number of bridges (in thousands)

All bridges

Deficient bridges

Source: GAO analysis of FHWA data.

Year

Decrease in deficient bridges, 1998-2007:

Increase in all bridges, 1998-2007:

172,683

583,401

20,366

16,416

152,317

599,817

Page 10 GAO-08-1127T 
Page 11 GAO-08-1127T 

Figure 2: Number of Structurally Deficient and Functionally Obsolete Bridges, 1998 

through 2007 

The average sufficiency rating of all bridges—including both deficient and 

not deficient bridges—also improved slightly between 1998 and 2007, from 

75 to 79 on the sufficiency rating’s 100-point scale.18 Additionally, while 

structurally deficient bridges generally have lower sufficiency ratings 

(average rating of 42 in 2007) than functionally obsolete bridges (average 

rating of 69 in 2007), the average sufficiency ratings of both types of 

deficient bridges improved slightly over the last decade. 

Improvements were most notable in bridges owned by local agencies and 

on rural routes, which may be attributable, in part, to the federal bridge 

program requirement—under HBP and some of its predecessor 

programs—that states spend a minimum amount of their apportionment 

 18The sufficiency rating is a score from 0 to 100 assigned to each bridge, reflecting its 

structural adequacy, safety, serviceability, and essentiality or relative importance for public 

use. A rating of 100 represents an entirely sufficient bridge and a 0 represents an entirely 

insufficient bridge. 

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Number of bridges (in thousands)

Year

Structurally deficient bridges

Functionally obsolete bridges

Source: GAO analysis of FHWA data.
Page 12 GAO-08-1127T 

on non-Federal-aid highway bridges.19 For example, from 1998 through 

2007, the average sufficiency rating for bridges owned by local agencies 

improved from 71 to 77, and the number of deficient bridges decreased by 

over 17 percent, from 99,492 to 82,101. During that same period, for 

bridges owned by state agencies, the average sufficiency rating improved 

from 79 to 82, and the number of deficient bridges decreased by 4 percent, 

from 70,066 to 67,232 (see fig. 3). 

Figure 3: Number of Deficient Bridges, by Bridge Owner, 1998 through 2007 

Note: Deficient bridges include both structurally deficient and functionally obsolete bridges. 

With respect to urban and rural bridges, the number of deficient rural 

bridges declined from 1998 through 2007 and the number of deficient 

 19Since 1978, a minimum of each state’s apportionment has to be spent on bridges that are 

off the Federal-aid highway system. Until the enactment of the 2005 surface transportation 

authorizing legislation, there was also a maximum ceiling, 35 percent, that could be spent 

on non-Federal-aid highway bridges. 

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Number of deficient bridges (in thousands)

Source: GAO analysis of FHWA data.

Year

Locally owned deficient bridges

State owned deficient bridges
Page 13 GAO-08-1127T 

urban bridges increased.20 From 1998 through 2007, the number of 

deficient rural bridges decreased by about 19 percent, from 130,910 to 

106,209.21 During that same period, the number of deficient urban bridges 

increased by about 11 percent, from 41,659 to 46,086 (see fig. 4). The 

average sufficiency rating for both rural and urban bridges improved 

slightly from 1998 through 2007; for rural bridges, the average rating 

increased from 74 to 78, and for urban bridges, the average rating 

increased from 79 to 82. 

Figure 4: Number of Deficient Bridges, by Rural and Urban Classification, 1998 

through 2007 

Note: Deficient bridges include both structurally deficient and functionally obsolete bridges. 

The impact of the HBP on the improvements in bridge conditions is 

difficult to determine for several reasons, including lack of information on 

 20A bridge is classified as rural in the NBI database if it is not located inside a designated 

urban area. 

21Approximately 75 percent of the nation’s bridges are rural, and 25 percent are urban. 

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Number of deficient bridges (in thousands)

Source: GAO analysis of FHWA data.

Year

Rural deficient bridges

Urban deficient bridges
state and local bridge spending, the expansion of bridge project eligibility, 

and limitations in the NBI data. First, the impact of the federal investment 

in the HBP is difficult to measure in part because there are no

comprehensive data for state and local spending on bridges. FHWA does 

track a portion of each state’s capital spending on bridges, and the agency

has generated a single, national level estimate for total bridge 

expenditures by all government levels; however, there are significant gaps

in this information, and neither source is comprehensive or detailed 

enough to be used to determine the impact of the HBP.22 The state 

transportation officials we spoke with during our site visits estimated that 

state and local spending on bridges ranged from the minimum match 

amount (generally 20 percent of the HBP apportionment amount) to more 

than four times the state’s apportioned HBP funds. Our previous work has 

shown that although federal investment in HBP and other Federal-aid 

highway programs has increased over time, this investment has not 

resulted in commensurate increases in the nation’s total government 

spending (federal, state, and local) on its highway system.23 In particular, 

as the level of federal funding has increased since the mid-1990s, states 

have not maintained their level of effort in highway spending, and federal 

funds have increasingly been substituted for state funds. This suggests that 

increased federal highway funding influences states and localities to 

substitute federal funds for state and local funds they otherwise would 

have spent on highways and bridges.

Second, the impact of the HBP is also difficult to measure because HBP 

funds can, in some cases, be used for a variety of bridge projects without 

regard to a bridge’s deficiency status or sufficiency rating. Therefore, 

simply measuring changes in the number of structurally deficient or 

functionally obsolete bridges does not reflect the full impact of the 

program since these measures do not capture the impact of the HBP 

investment in the other eligible activities that do not necessarily result in 

 22For example, while FHWA does track a portion of bridge capital spending on a state by

state basis, the data does not include (1) state spending on bridges located on local roads 

and (2) most local government spending on bridges. In addition, while FHWA generates a

single, national-level estimate for total bridge expenditures at all government levels, this 

estimate cannot be used to determine the impact of the HBP by state or by bridge because 

it is a national aggregate. Moreover, neither of these two FHWA data sources on bridge

spending includes noncapital activities funding by the HBP, such as systematic preventive 

maintenance, anti-icing and deicing applications, and painting.

23GAO, Federal-Aid Highways: Trends, Effect on State Spending, and Options For Future 

Program Design, GAO-04-802 (Washington, D.C.: Aug. 31, 2004). 

Page 14 GAO-08-1127T 
an immediate reduction in the number of deficient bridges. Without 

quantifiable performance measures to track the full range of desired 

outcomes for the HBP, it is difficult to measure the program’s impact and 

determine the extent to which the program is serving its stated purpose. 

Finally, another difficulty in determining the impact of HBP funding 

occurs because the NBI does not readily permit changes in the condition 

of a group of bridges to be tracked across time. Each bridge in the NBI is 

assigned an identifying number by the relevant state DOT. However, the 

identifying number for a bridge at a specific location may change over the

life of that bridge. Such a change may occur when a state renumbers, 

replaces, or closes and subsequently reopens a bridge. As a result, it is 

difficult to track changes in the condition of any specific bridge or group 

of bridges to determine if, for example, the same bridges that were 

deficient in 1998 are still deficient today, to see how many bridges have

been replaced, or to determine the impact of new bridges added to the 

inventory (which may not be funded by the HBP) on the overall condition

of the nation’s bridges. 

Evaluating the impact of the HBP is important not only to understand the 

outcomes of past spending but also to determine how to sensibly invest 

future federal resources. The number of HBP-eligible bridges is expected 

to increase as a large share of the nation’s bridges built in the 1960s and 

early 1970s age and become eligible for rehabilitation and replacement as 

a group; as a result, states and local agencies may see a spike in their need 

for bridge rehabilitation and replacement funding. In this environment of 

increasing demand for limited resources, it is especially important for 

FHWA and Congress to be able to evaluate the impact of the HBP in order 

to ensure that the program is providing an acceptable return on 

investment and addressing national transportation priorities. 

The HBP, while generally helping to improve bridge conditions, does not 

fully align with our principles for re-examining surface transportation 

programs in that the bridge program lacks focus, performance measures, 

and sustainability. Our principles, which are based on our prior work and 

federal laws and regulations, include: (1) ensuring program goals are well 

defined and focused on the federal or national interest, (2) incorporating 

performance and accountability into funding decisions, (3) employing the 

best tools and approaches to emphasize return on targeted federal 

investment, and (4) ensuring fiscal sustainability. 

The HBP Lacks 

Focus, Performance 

Measures, and 

Sustainability 

Page 15 GAO-08-1127T 
First, HBP’s goals are not focused on a clearly identified federal interest. 

Over the years, the program’s statutory goals have expanded from 

improving deficient bridges to supporting seismic retrofitting, preventive 

maintenance, and many other activities, thus expanding the federal 

interest to potentially include almost any bridge in the country. Our 

previous work has emphasized the importance of identifying clear areas of 

federal interest as a first step in determining program goals. For example, 

if mobility is determined to be a key federal interest and a primary goal, 

the HBP could be targeted toward bridges whose conditions have the most 

impact on congestion and economic competitiveness and that carry higher 

levels of traffic or freight than those bridges in remote areas that may 

serve only a few people each day. If rehabilitating and reducing deficient 

bridges is determined to be a key federal interest, then the program could 

be further targeted toward that goal. The federal interest may also be 

greater in bridge projects that are too expensive for states to undertake 

without additional federal assistance or in projects that extend beyond the 

borders of a single state. Once the federal interest has been determined, 

our principles call for basing the federal share of the cost of bridge 

projects on the level of federal interest. 

Second, there is no clear tie between HBP funding and performance. HBP 

funds are apportioned to states without regard to program performance 

because the HBP formula is based on a calculation of needed repairs to 

deficient bridges but does not consider a state’s efforts or effectiveness in 

reducing its inventory of deficient bridges or controlling costs. Because 

the formula does not factor in other eligible program activities, such as 

systematic preventive maintenance, there is no link between the 

apportionment formula and the states’ performance of these activities. 

Without performance measures to link funding to performance, states lack 

an incentive to improve the return on the federal investment and are not 

held accountable for the results of their investments. Our work has shown 

that an increased focus on performance and accountability for results can 

help the federal government better target limited federal resources. 

Third, the HBP generally lacks sufficient tools to determine the effects of

the federal investment in bridges. In this regard, bridge management 

systems, which are currently used by many states but not required by the 

program’s authorizing legislation, may be useful for prioritizing projects 

and making funding decisions to improve results and emphasize return on 

investment. 

Finally, the HBP’s fiscal sustainability remains a challenge in light of aging 

bridge infrastructure, coupled with the declining purchasing power of 

Page 16 GAO-08-1127T 
funding currently available for bridge maintenance, rehabilitation, 

replacement and the recent growth in construction costs. Based on our 

prior work, two tools that could possibly improve the sustainability of the 

HBP are a maintenance-of-effort requirement and tolling. A maintenanceof-effort requirement, whereby state or local grantees would be required to

maintain their own level of funding in order to receive HBP funds, could 

reduce the potential substitution of federal funds for state and local funds 

under the program. In addition, our prior work has shown that removing 

barriers to, or even promoting, tolling can lead to more efficient 

management of existing infrastructure and capacity.24 Addressing the 

HBP’s future fiscal sustainability is critical, given the overall fiscal 

imbalance facing the nation and the lack of assurance that HBP funding is

allocated to projects that are in the federal interest and provide the best 

return on investment. 

Our work on the HBP can provide some perspective on several provisions

in the proposed legislation under review by this committee, the National 

Highway Bridge Reconstruction and Inspection Act of 2008 (S. 3338). The 

legislation proposes, among other things, to authorize an additional $1 

billion for fiscal year 2009 from the U.S. Treasury’s general fund to address 

bridge infrastructure. The legislation would also require DOT to 

strengthen bridge inspection standards, adopt a risk-based process for 

prioritizing certain bridge rehabilitation and replacement projects, and 

require that states develop 5-year performance plans for bridge 

inspections and for the rehabilitation or replacement of deficient bridges.

As summarized below, our work on the HBP is related to several 

provisions in the proposal: 

Observations on 

Proposed Bridge 

Legislation 

• For example, the legislation calls for DOT to apply a risk-based

prioritization process to every structurally deficient or functionally 

obsolete bridge in the nation. While such a process could potentially help

target scarce federal resources to bridges that are most critical to safety 

and mobility, many state transportation officials we interviewed during 

our work raised questions about the appropriateness of focusing on all 

deficient bridges, noting that all deficient bridges are not necessarily 

unsafe and some large-scale deficient bridge projects can be too costprohibitive to be implemented with HBP funds alone. Also, the legislation 

 24GAO, Highway Finance: States’ Expanding Use of Tolling Illustrates Diverse Challenges 

and Strategies, GAO-06-554 (Washington, D.C.: June 28, 2006). 

Page 17 GAO-08-1127T 
is unclear about how, if at all, the new risk-based prioritization process 

will differ from or relate to DOT’s established sufficiency rating process. 

FHWA uses sufficiency ratings primarily to determine HBP eligibility and 

apportion funds. We found that states may consider sufficiency ratings in

their prioritization processes but generally do not rely on these to 

prioritize bridge projects. 

• In addition, the legislation calls for DOT to require states to develop 5-year 

performance plans covering the inspection and rehabilitation or 

replacement of all structurally deficient or functionally obsolete bridges. 

We support the use of performance plans to articulate program goals that 

are in the federal interest, encourage accountability for results, and help 

ensure that the federal government targets resources to programs that best 

achieve intended outcomes and national priorities. Our work has shown 

that the current HBP funding formula is not linked to a state’s 

performance in reducing its inventories of deficient bridges and we are 

recommending in our report being issued today that DOT work with 

Congress to define specific national goals and performance measures for 

the HBP. This legislative provision might be strengthened by requiring 

states to report on their progress in achieving their goals as part of each

annual update to their performance plan. Also, the legislation requires that 

the performance plans be focused on all deficient bridges, and the same 

issue that I raised earlier about the appropriateness of this focus applies 

here as well. 

• The legislation also calls for DOT to require the states to develop and 

implement a bridge management system. In our work on the HBP, all six 

states we visited had adopted, or were considering, some form of bridge 

management system to help manage their bridge assets and more 

efficiently allocate limited HBP resources among competing bridge 

priorities. In the report we are releasing today, we are recommending that 

DOT evaluate and incorporate into the HBP best tools and practices, such 

as bridge management systems. 

Although many aspects of the HBP are carried out at the state level—with 

ultimate responsibility for bridge inspection and project selection residing 

with the states—the federal government bears responsibility for ensuring 

that the program achieves results that are in the federal interest and that 

the program’s resources are allocated efficiently. The purpose of the HBP

has greatly expanded over the years, making nearly any bridge potentially

eligible for federal funding, and as a result, the federal interest in bridges 

lacks focus. Additionally, many state officials told us that measures used 

by the HBP to apportion federal funds—bridge deficiency status and 

Conclusions and 

Recommendations 

Page 18 GAO-08-1127T 
sufficiency ratings—are not necessarily good proxies for the safety or risk 

associated with specific bridges. Even though data indicate that the 

number of structurally deficient bridges has declined over the last 10 

years, most of this improvement has been in locally owned and rural 

bridges. Oftentimes, the largest and most critical bridges carrying more 

interstate commerce are too expensive to be funded by the HBP and so 

require other funding sources to be replaced or rehabilitated. Moreover, 

without comprehensive data on state and local spending on bridges, it is 

impossible either to distinguish the impact of HBP funding from the 

impact of state and local bridge funding or to determine the extent to 

which states are substituting HBP funding for state and local funds that 

would otherwise have been spent on bridges. Absent clear goals and 

related performance measures for the HBP, it is difficult to determine the 

overall effectiveness of the program’s investment in bridges. 

Our principles have suggested several ways to improve the HBP to ensure 

that it is more focused and performance-based in the future. For example, 

tools such as bridge management systems provide bridge managers with a 

more systematic approach to prioritizing projects and making funding 

decisions. Our work has shown that some states are using bridge 

management systems and other tools that generally exceed federal 

standards. Additionally, linking program goals to performance measures to 

determine whether goals are met and using that information to select 

projects and make funding decisions, can create incentives for state and 

local governments to improve the performance of their bridge programs, 

as well as the overall transportation system. As the projected revenue

shortfall in the Highway Trust fund rapidly approaches and as bridge costs 

rise and infrastructure continues to age, incorporating strategies to better 

ensure the fiscal sustainability of the HBP is also critical. 

To improve the focus, performance, and sustainability of the HBP, the 

report we are releasing at this hearing recommends that the Secretary of 

Transportation work with Congress to take the following actions: 

• identify and define specific national goals for the HBP; 

• determine the performance of the program by developing and 

implementing performance measures related to the goals for the HBP; 

• identify and evaluate best tools and practices that can potentially be 

incorporated into the HBP, such as bridge management systems; and 

Page 19 GAO-08-1127T 
• review and evaluate HBP funding mechanisms to align funding with 

performance and support a targeted and sustainable federal bridge 

program. 

In reviewing a draft of the report, DOT officials said that they generally

agreed with our findings and recommendations, and they provided 

technical comments which we incorporated in the report and this 

testimony, as appropriate. DOT officials also commented that they thought

our re-examination principles had broader applicability than just the 

HBP—noting that DOT had incorporated our principles into the 

Department’s recent proposal for reforming surface transportation 

programs. DOT’s reform proposal, released in July 2008, recommends 

consolidating the existing network of over 100 surface transportation 

programs into eight broad, intermodal programs.25 The officials noted that 

DOT’s reform proposal articulates a narrower federal interest and a 

framework for performance management tied to clearer goals for surface 

transportation programs. We have not commented on DOT’s reform 

proposal, and the outcome of that proposal in the surface transportation 

reauthorization debate that will occur during 2009 is uncertain. However, 

we agree with DOT that our re-examination principles are applicable at a 

broader level than a specific program like HBP; in fact, we developed our 

principles because of (1) our concerns, raised in prior work, that many 

federal surface transportation programs are not effective at addressing key 

transportation challenges such as growing congestion and freight demand

and (2) our conclusion that our principles could help drive the reexamination of those programs and help assess options for restructuring 

the entire federal surface transportation program.26

Chairman Boxer, this concludes my prepared statement. I would be happy 

to respond to any questions that you or members of the committee may 

have. 

 25DOT, Refocus, Reform, Renew: A New Transportation Approach for America

(Washington, D.C.: July 29, 2008). 

26See GAO-08-400. 

Page 20 GAO-08-1127T 
For further information on this statement, please contact Katherine 

Siggerud at (202) 512-2834 or siggerudk@gao.gov. Individuals making key 

contributions to this testimony were Rita Grieco, Assistant Director; 

Claudia Becker; Stephanie Fain; Carol Henn; Bert Japikse; Delwen Jones; 

Leslie Locke; and Sara Ann Moessbauer. 

Page 21 GAO-08-1127T 

GAO Contact and 

Staff 

Acknowledgments 

(542149) 
This is a work of the U.S. government and is not subject to copyright protection in the 

United States. The published product may be reproduced and distributed in its entirety 

without further permission from GAO. However, because this work may contain 

copyrighted images or other material, permission from the copyright holder may be 

necessary if you wish to reproduce this material separately. 
GAO’s Mission The Government Accountability Office, the audit, evaluation, and 

investigative arm of Congress, exists to support Congress in meeting its 

constitutional responsibilities and to help improve the performance and 

accountability of the federal government for the American people. GAO 

examines the use of public funds; evaluates federal programs and policies; 

and provides analyses, recommendations, and other assistance to help

Congress make informed oversight, policy, and funding decisions. GAO’s 

commitment to good government is reflected in its core values of 

accountability, integrity, and reliability. 

The fastest and easiest way to obtain copies of GAO documents at no cost

is through GAO’s Web site (www.gao.gov). Each weekday, GAO posts 

newly released reports, testimony, and correspondence on its Web site. To

have GAO e-mail you a list of newly posted products every afternoon, go 

to www.gao.gov and select “E-mail Updates.” 

The first copy of each printed report is free. Additional copies are $2 each. 

A check or money order should be made out to the Superintendent of 

Documents. GAO also accepts VISA and Mastercard. Orders for 100 or 

more copies mailed to a single address are discounted 25 percent. Orders 

should be sent to: 

U.S. Government Accountability Office 

441 G Street NW, Room LM 

Washington, DC 20548 

To order by Phone: Voice: (202) 512-6000 

TDD: (202) 512-2537 

Fax: (202) 512-6061 

Contact: 

Web site: www.gao.gov/fraudnet/fraudnet.htm

E-mail: fraudnet@gao.gov

Automated answering system: (800) 424-5454 or (202) 512-7470 

Ralph Dawn, Managing Director, dawnr@gao.gov, (202) 512-4400 

U.S. Government Accountability Office, 441 G Street NW, Room 7125 

Washington, DC 20548 

Chuck Young, Managing Director, youngc1@gao.gov, (202) 512-4800 

U.S. Government Accountability Office, 441 G Street NW, Room 7149 

Washington, DC 20548 

Obtaining Copies of 

GAO Reports and 

Testimony

Order by Mail or Phone 

To Report Fraud,

Waste, and Abuse in 

Federal Programs 

Congressional 

Relations 

Public Affairs 

PRINTED ON RECYCLED PAPER