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Report to Congressional Committees: 

United States Government Accountability Office: 
GAO: 

September 2008: 

Highway Bridge Program: 

Clearer Goals and Performance Measures Needed for a More Focused and 
Sustainable Program: 

GAO-08-1043: 

GAO Highlights: 

Highlights of GAO-08-1043, a report to congressional committees. 

Why GAO Did This Study: 

The August 1, 2007, collapse of a Minnesota bridge raised nationwide 
questions about bridge safety and the U.S. Department of 
Transportation’s (DOT) ability to prioritize resources for bridges. The 
Highway Bridge Program (HBP), the primary source of federal funding for 
bridges, provided over $4 billion to states in fiscal year 2007. This 
requested study examines (1) how the HBP addresses bridge conditions, 
(2) how states use HBP funds and select bridge projects for funding, 
(3) what data indicate about bridge conditions and the HBP’s impact, 
and (4) the extent to which the HBP aligns with principles GAO 
developed, based on prior work and federal laws and regulations, for re-
examining surface transportation programs. GAO reviewed program 
documents; analyzed bridge data; and met with transportation officials 
in states that have high levels of HBP funding and large bridge 
inventories, including California, Missouri, New York, Pennsylvania, 
Texas, and Washington. 

What GAO Found: 

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; 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. 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 systematic preventive maintenance 
projects. 

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, as measured by the number of deficient bridges and 
average sufficiency rating, improved from 1998 through 2007. 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 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. 

The HBP does not fully align with GAO’s principles, which are based on 
GAO’s prior work and federal laws and regulations, 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 or national 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. 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. 

What GAO Recommends: 

GAO is recommending that DOT work with Congress to identify specific 
program goals in the national interest, develop and implement 
performance measures, incorporate best tools and practices, and review 
the program’s funding mechanisms. DOT officials generally agreed with 
the findings and recommendations in this report, providing technical 
clarifications which we incorporated, as appropriate. 

To view the full product, including the scope and methodology, click on 
[hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-08-1043]. For more 
information, contact Katherine Siggerud at (202) 512-2834 or 
siggerudk@gao.gov. 

[End of section] 

Contents: 

Letter: 

Results in Brief: 

Background: 

The HBP Classifies Bridges Based on Their Condition and Provides Funds 
to States to Improve Bridge Conditions: 

State DOTs Exercise Discretion in Determining How to Use HBP Funds and 
Select Bridge Projects for Funding: 

Available Data Indicate That the Overall Condition of the Nation's 
Bridges Has Improved, but the Impact of the HBP Is Difficult to 
Determine: 

The HBP Lacks Focus, Performance Measures, and Sustainability: 

Conclusions: 

Recommendation for Executive Action: 

Agency Comments: 

Appendix I: Scope and Methodology: 

Appendix II: Bridge Maintenance Responsibility, Type of Use, and Age: 

Appendix III: GAO Contact and Staff Acknowledgments: 

Table: 

Table 1: Information on Bridge Characteristics and HBP Funding in 
States Selected for Site Visits, Fiscal Year 2007: 

Figures: 

Figure 1: Key Factors That May Contribute to a Bridge's Classification 
as Structurally Deficient: 

Figure 2: Key Factors That May Contribute to a Bridge's Classification 
as Functionally Obsolete: 

Figure 3: Process for Designating Bridges as Eligible for HBP Funding: 

Figure 4: Trends in Numbers of Bridges and Deficient Bridges, 1998 
through 2007: 

Figure 5: Number of Structurally Deficient and Functionally Obsolete 
Bridges, 1998 through 2007: 

Figure 6: Number of Deficient Bridges, by Bridge Owner, 1998 through 
2007: 

Figure 7: Number of Deficient Bridges, by Rural and Urban 
Classification, 1998 through 2007: 

Figure 8: Application of Key Principles to the HBP: 

Figure 9: Bridge Inventory Count, Deck Area, and ADT, by Owner, 2007: 

Figure 10: Bridge Inventory Count, Deck Area, and ADT, by NHS 
Classification, 2007: 

Figure 11: Number of Bridges, by Year Built, 2007: 

Figure 12: Deck Area of Bridges, by Year Built, 2007: 

Figure 13: Range of Sufficiency Ratings, by Bridge Age, 2007: 

Figure 14: Bridge Deficiency Status, by Year Built or Reconstructed, 
2007: 

Abbreviations: 

ADT: average daily traffic: 

AASHTO: American Association of State Highway and Transportation 
Officials: 

Caltrans: California Department of Transportation: 

DOT: Department of Transportation: 

FHWA: Federal Highway Administration: 

HBP: Highway Bridge Program: 

HBRRP: Highway Bridge Replacement and Rehabilitation Program: 

MnDOT: Minnesota Department of Transportation: 

MoDOT: Missouri Department of Transportation: 

NBI: National Bridge Inventory: 

NBIP: National Bridge Inspection Program: 

NBIS: National Bridge Inspection Standards: 

NHS: National Highway System: 

NYSDOT: New York State Department of Transportation: 

PennDOT: Pennsylvania Department of Transportation: 

SAFETEA-LU: Safe, Accountable, Flexible, and Efficient Transportation 
Equity Act--A Legacy for Users: 

TxDOT: Texas Department of Transportation: 

WSDOT: Washington State Department of Transportation: 

[End of section] 

United States Government Accountability Office: Washington, DC 20548: 

September 10, 2008: 

The Honorable Barbara Boxer: 
Chairman: 
The Honorable James Inhofe: 
Ranking Member: 
Committee on Environment and Public Works: 
United States Senate: 

The Honorable Carl Levin: 
Chairman: 
The Honorable Norm Coleman: 
Ranking Member: 
Permanent Subcommittee on Investigations: 
Committee on Homeland Security and Governmental Affairs: 
United States Senate: 

The sudden collapse of the I-35W bridge in Minneapolis, Minnesota, on 
August 1, 2007, raised questions about the overall condition of the 
nation's bridges and the federal and state roles in funding and 
ensuring the safety of roads and bridges in the United States. Bridges 
are critical elements of the nation's transportation network, 
supporting commerce, economic vitality, and personal mobility. In 2007, 
there were nearly 600,000 bridges in the United States which carried 
the nation's passenger car, truck, bus transit, and commercial vehicle 
traffic over waterways, highways, railways, and other road 
obstructions. The Highway Bridge Program (HBP), which is administered 
by the Federal Highway Administration (FHWA) and is the primary federal 
program used to fund the replacement and rehabilitation and systematic 
preventive maintenance of bridges nationwide, provided over $4 billion 
to states in fiscal year 2007. Since the Minnesota bridge collapse, 
there have been calls for increased investment in bridge 
infrastructure. On July 24, 2008, the House of Representatives passed 
legislation that would authorize an additional $1 billion for fiscal 
year 2009 to address bridges, if passed by Congress, and shortly 
thereafter, a Senate companion bill to that legislation was introduced 
in the Senate Committee on Environment and Public Works.[Footnote 1] 

Calls for increased investment in bridge infrastructure coincide with 
increasing 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. As a result, in 2007, we added financing the nation's federal 
transportation infrastructure to GAO's High Risk List.[Footnote 2] We 
have also recently called for a fundamental re-examination of 
government programs and commitments, and have identified federal 
surface transportation programs as particularly ready for re- 
examination.[Footnote 3] Such a re-examination would provide an 
opportunity to address emerging needs by eliminating outdated or 
ineffective programs, more sharply defining the federal role in 
relation to state and local roles, and modernizing relevant programs. 
Our prior work has found that the expansion of many federal surface 
transportation programs has resulted in broader program goals and 
varying priorities, making it difficult to determine the programs' 
impact. For example, federal transportation programs currently address 
a wide variety of transportation, environmental, and societal goals 
beyond the initial federal focus on highway infrastructure, such as 
promoting transit use in urban areas, supporting air quality 
improvements and the use of alternative fuels, providing access for 
transportation-disadvantaged populations (e.g., elderly, persons with 
disabilities, and low-income workers), and other goals. 

This report responds to your request for information on how the HBP is 
carried out by federal, state, and local transportation officials, as 
well as any opportunities for program improvement. Specifically, the 
report addresses: (1) how the HBP identifies and addresses the 
condition of the nation's highway bridges, (2) how states use their HBP 
funds and select specific bridge projects for funding, (3) what 
available data indicate about the condition of the nation's bridges and 
the impact of the HBP, and (4) the extent to which the HBP aligns with 
principles we developed to guide the re-examination of surface 
transportation programs. 

To determine how the HBP identifies and addresses the condition of the 
nation's bridges, we reviewed relevant legislation, regulations, and 
FHWA program documents; reviewed FHWA's historical data on the 
apportionment of HBP funds among states; and interviewed FHWA 
officials. 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, and 
toured bridges. We selected this nongeneralizable sample of 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 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; interviewed federal, state, and local 
transportation officials; and examined relevant GAO reports. 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, 
and ensuring fiscal sustainability.[Footnote 4] This report focuses on 
the HBP; the scope of our study did not include an investigation of the 
cause of the I-35W bridge collapse or an evaluation of the National 
Bridge Inspection Standards.[Footnote 5] 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. More details on our scope and methodology can be found in 
appendix I. 

Results in Brief: 

The HBP classifies bridges based on their condition and provides 
funding for states to improve their bridges. Using data gathered 
through bridge inspections, FHWA assigns each bridge in the NBI a 
sufficiency rating and classifies it as deficient--structurally 
deficient or functionally obsolete--or not deficient.[Footnote 6] A 
structurally deficient bridge generally has some component, such as the 
bridge deck, rated in poor condition. A functionally obsolete bridge is 
generally in fair or better condition, but because of changing traffic 
demands and design standards, the bridge may no longer be suitable for 
the traffic it serves. A bridge generally must be either structurally 
deficient or functionally obsolete and have a sufficiency rating 
[Footnote 7] of 80 or less to qualify for replacement or rehabilitation 
with HBP funding. However, other bridge activities--such as seismic 
retrofitting of bridges and systematic preventive maintenance projects--
are also eligible for HBP funds, regardless of whether the bridge 
qualifies for replacement or rehabilitation. Despite the broad range of 
characteristics making a bridge eligible for the use of federal funds, 
each state's HBP apportionment amount is determined largely by the deck 
area of bridges that are eligible for replacement or rehabilitation. 
HBP funds are apportioned to states using a needs-based process that 
considers each state's amount of structurally deficient and 
functionally obsolete deck area and other factors, including minimum 
and maximum funding guarantees.[Footnote 8] 

The HBP affords state transportation departments discretion in using 
their HBP funds, and as a result, states select bridge projects and use 
HBP funds in a variety of ways. For example, while the primary purpose 
of the HBP is to enable states to improve the condition of their 
structurally deficient and functionally obsolete bridges, the program 
does not require states to focus their resources on reducing their 
inventories of deficient bridges. As a result, state transportation 
departments we visited have established a range of bridge priorities. 
For example, Texas transportation officials have focused on reducing 
their number of structurally deficient bridges, while California 
transportation officials have focused on seismically retrofitting 
bridges. In addition, some states opt to transfer a portion of their 
HBP funds to fund other transportation priorities as allowed by the 
program. For example, between 1998 and 2007, 27 states transferred HBP 
funds to other Federal-aid highway programs.[Footnote 9] State 
transportation officials we interviewed cited several reasons for not 
focusing their HBP resources on deficient bridges, including: deficient 
bridges are not necessarily unsafe; the HBP formula used for the 
apportionment of HBP funds provides no incentives for states to improve 
deficient bridges; and the high costs of improving some deficient 
bridges are prohibitive. Additionally, state transportation departments 
use a variety of criteria, tools, and methods to select among potential 
bridge projects. For example, officials in the six states we visited 
considered a range of criteria, including bridge condition ratings, 
average daily traffic, funding availability, and state and local 
transportation priorities, among others. 

Bridge conditions, as measured by the number of deficient bridges and 
the average sufficiency rating of all bridges in the NBI, improved from 
1998 through 2007, but it is difficult to determine the impact of the 
HBP. Over this period, the total number of deficient bridges declined 
by almost 12 percent, and the number of structurally deficient bridges 
decreased by 22 percent. In addition, the average bridge sufficiency 
rating slightly improved by 4 points, from 75 to 79, on a 100-point 
scale. Furthermore, bridges owned by local agencies and located on 
rural routes improved more than bridges owned by state agencies and 
located on urban routes, likely due in part to the requirement that 
states spend a minimum amount on such bridges. However, the impact of 
the HBP is difficult to measure for several key reasons. Without 
comprehensive data on total state and local spending on bridges, it is 
impossible either to definitively 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. Additionally, as 
more activities have become eligible for HBP funding, measuring changes 
in the number of deficient bridges and average sufficiency rating 
captures only part of the impact of the HBP. Also, because NBI data do 
not readily permit the tracking of changes in the condition of a group 
of bridges across time, it is difficult to determine the impact of HBP 
funding on bridges. Our analysis of trends in bridge condition shows 
that a large share of the nation's bridges could soon become eligible 
for HBP funding for bridge rehabilitation and replacement projects. 
This anticipated spike in demand for limited HBP funding makes it 
increasingly important to be able to determine the impact of the HBP 
and have some level of assurance that the funds are being applied cost 
effectively to further nationally-defined goals for improving and 
preserving the nation's bridges. 

The HBP does not fully align with principles established in our 
previous work and developed for re-examining surface transportation 
programs because the program lacks goals that are focused on a clearly 
identified federal or national interest, performance measures, and 
sustainability. For example, program goals, which are established in 
federal statute,[Footnote 10] have expanded from improving deficient 
bridges to supporting seismic retrofitting, systematic preventive 
maintenance, and many other activities, thus expanding the federal 
interest to potentially include almost any bridge in the country. 
Additionally, 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. Without performance measures to link 
funding and 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. In addition, the 
HBP generally lacks sufficient tools to determine the effects of the 
federal investment in bridges. In this regard, bridge management 
systems,[Footnote 11] which are currently used by many states but not 
required by 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, 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. Accordingly, we are recommending that 
the Secretary of Transportation work with Congress to identify and 
define specific national goals for the HBP; determine the impact of the 
program by developing and implementing performance measures related to 
the program's goals; identify and evaluate best tools and practices, 
such as bridge management systems, that can potentially be incorporated 
into the HBP; and review and evaluate HBP funding mechanisms to align 
funding with performance and support a targeted and sustainable federal 
bridge program. In commenting on a draft of the report, DOT officials 
said that they generally agreed with our findings and recommendations, 
and they provided technical clarifications, which we incorporated in 
the report, 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. 

Background: 

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.[Footnote 12] 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. 

The NBIP establishes standards--National Bridge Inspection Standards 
(NBIS)--and program requirements for the proper safety inspection and 
evaluation of bridges. The primary purpose of these standards, which 
were first issued in 1971, is to ensure the safety of the traveling 
public. The NBIS establishes by whom, with what frequency, and how 
bridge inspections are to be completed, including the following: 

* State departments of transportation (DOTs) must have a bridge 
inspection organization that is responsible for carrying out the NBIP's 
national-level policies, procedures, and requirements for inventory, 
inspection, bridge load ratings, quality assurance, and reports. 

* Bridges must be inspected as thoroughly as necessary to clearly 
establish their condition and to ensure their continued safe operation, 
using a detailed manual prepared by the American Association of State 
Highway and Transportation Officials (AASHTO). Routine bridge 
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 condition 
data, during the inspection and report that information to the NBI, 
maintained by FHWA headquarters. 

With the exception of federally owned highway bridges, state DOTs are 
responsible for inspecting bridges within their state, maintaining a 
current bridge inventory, and reporting bridge condition data to FHWA. 
According to the FHWA, state DOTs should have agreements in place that 
outline inspection processes and responsibilities for other local 
agencies within the state--such as cities, counties, toll authorities, 
and ports--and other state agencies that own and maintain bridges that 
carry public travel. Although state DOTs may delegate some bridge 
inspection responsibilities to other agencies or private contractors, 
they retain ultimate responsibility for ensuring that bridge 
inspections are completed and for inventorying bridges according to 
federal standards. 

In accordance with the NBIS, states also prepare and maintain an 
inventory of their bridges and submit inventory updates to FHWA each 
year. The NBI, the primary source of information on the nation's 
bridges, is comprised of 94 data items collected by states and others 
during bridge inspections. The 94 data items include the minimum bridge 
data items that states are required to inspect and report on. The NBI 
contains information for each bridge describing its location, age, 
condition, and inspection dates. The NBI data also identify the 
ownership and size of the nation's bridges. For example, 2007 NBI data 
indicate that federal agencies owned about 1 percent of bridges, while 
state and local agencies owned 48 percent and 51 percent, respectively. 
State agencies, however, owned more than three-quarters of the nation's 
bridge deck area because state-owned bridges are typically larger. (See 
app. II for additional analysis of national bridge data and trends). 
Each year, state DOTs submit the latest information on all of their 
bridges to FHWA to update the NBI. 

FHWA uses information in the NBI to annually apportion HBP funds to the 
states. The HBP provides funding assistance to the states to improve 
the condition of their bridges and specifies seven activities that 
states may undertake with program funds, 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 applications. In addition, FHWA has determined 
that bridge inspections, equipment for bridge inspections, and bridge 
management systems are consistent with the purpose of the HBP and 
therefore are also eligible for HBP funds. 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,[Footnote 13] though a penalty is invoked 
by reducing the state's HBP funds in the succeeding year by the amount 
transferred. 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.[Footnote 14] 

Both the NBIP and HBP are administered by FHWA's Office of Bridge 
Technology and its 52 division offices located throughout the states. 
[Footnote 15] FHWA's Office of Bridge Technology is responsible for 
developing and recommending program policies, regulations, 
instructions, and procedures, and for providing technical guidance to 
states. The division offices, each headed by an administrator, are 
FHWA's in-state contact for state transportation officials. Division 
office officials are responsible for monitoring compliance with bridge 
inspection standards and other legal requirements, reviewing and 
approving state applications for HBP funds, and providing technical 
guidance and advice to state officials about their bridges. 

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.[Footnote 16] Federal-aid highway bridges are generally located 
on the National Highway System (NHS), a 160,000-mile network that 
carries over 40 percent of the nation's highway traffic.[Footnote 17] 
Non-Federal-aid highway bridges are generally located on local or rural 
roads that carry lower volumes of traffic than state-owned bridges. 
[Footnote 18] 

The HBP Classifies Bridges Based on Their Condition and Provides Funds 
to States to Improve Bridge Conditions: 

The HBP classifies bridges based on their condition and determines how 
program funding is apportioned among the states to improve bridge 
conditions. Using the data collected by state and local governments 
during bridge inspections, FHWA calculates a sufficiency rating and 
classifies each bridge according to its deficiency status. Bridges 
generally are eligible to receive HBP funding for replacement and 
rehabilitation based on their sufficiency ratings and deficiency 
classifications.[Footnote 19] HBP funds are apportioned to states using 
a needs-based process that considers the deck area of deficient bridges 
and other factors. 

The HBP Classifies Bridges Based on Condition: 

Under the HBP, FHWA uses bridge inspection data to classify bridges in 
two key ways, by calculating a sufficiency rating and by determining 
deficiency status. First, sufficiency ratings are calculated using a 
formula that considers 20 of the 94 NBI data items that reflect a 
bridge's structural adequacy, safety, serviceability, and essentiality 
for public use. FHWA assigns each bridge in the NBI a rating between 0 
and 100, indicating its sufficiency to remain in service. A rating of 
100 represents an entirely sufficient bridge, while a rating of 0 
represents an entirely insufficient bridge. FHWA uses sufficiency 
ratings primarily to determine HBP eligibility and apportion funds. 
States may consider sufficiency ratings in their prioritization 
processes but generally do not rely on these ratings to set their 
project priorities. FHWA program documents state that sufficiency 
ratings are not intended to be an accurate representation of priority 
for bridge replacement or rehabilitation projects. Secondly, FHWA 
classifies bridges as not deficient or deficient. Like the sufficiency 
rating, the classification of a bridge as deficient or not is 
calculated using a formula that is applied to data contained in the 
NBI. Bridges rated by inspectors as acceptable in condition, geometric 
configuration, and design are classified as not deficient, and bridges 
that receive low ratings on structural or functional bridge elements 
are classified as deficient.[Footnote 20] In a 2007 report to Congress 
on the condition of the nation's bridges, FHWA noted that classifying a 
bridge as deficient does not immediately imply that it is likely to 
collapse or that it is unsafe.[Footnote 21] According to FHWA, if 
proper vehicle weight restrictions are posted and enforced, deficient 
bridges can continue to serve most traffic conditions. FHWA requires 
that if a bridge owner determines that a bridge is unsafe, it must be 
closed to traffic. 

There are two distinct types of deficient bridges--structurally 
deficient and functionally obsolete. A bridge is considered 
structurally deficient if the substructure, superstructure, or deck is 
rated in poor condition because of deterioration or damage, or the 
waterway opening provided by the bridge is determined to be 
insufficient to the point of causing intolerable traffic interruptions 
(see figure 1).[Footnote 22] For example, the I-35W bridge was 
classified as structurally deficient because its superstructure was 
rated as poor. [Footnote 23] 

Figure 1: Key Factors That May Contribute to a Bridge's Classification 
as Structurally Deficient: 

[See PDF for image] 

This figure is an illustration of key factors that may contribute to a 
bridge's classification as structurally deficient, as follows: 

Superstructure: 
Physical condition of structural members, including cracking,
deterioration, and section loss. 

Deck: 
Concrete deck—cracking, scaling, spalling, leaching, chloride
contamination, potholing, delamination, and full or partial depth 
failures.
Steel grid decks—broken welds, broken grids, and section loss of grid.
Timber decks—splitting, crushing, fastener failure, and rotting. 

Substructure: 
Physical condition of piers, abutments, piles, and footings with
visible signs of cracking, section loss, settlement, misalignment,
scour, collision damage, and corrosion. 

Overall structural evaluation: 
Structural evaluation rating is based upon average daily traffic
using the bridge, load level that the structure can safely support,
superstructure condition, and substructure condition. 

Source: GAO. 

[End of figure] 

A functionally obsolete bridge may be in good condition, but its poor 
configuration or design may no longer be adequate for the traffic it 
serves. Bridges are generally classified as functionally obsolete as a 
result of changing traffic demands or changes in geometric design 
standards since construction and are not structurally unsound. For 
example, geometric deficiencies, such as a bridge being narrower than 
current standards allow, may cause a bridge to be classified as 
functionally obsolete, but these deficiencies are not connected to the 
structural condition of the bridge. Factors that are considered in 
determining whether a bridge should be classified as functionally 
obsolete include clearances above or below the bridge, appropriate 
bridge deck geometry (the deck and roadway widths), alignment of the 
approach road (the reduction of speed as a vehicle crosses the bridge 
due to alignment of the road versus the bridge), count of average daily 
traffic using the bridge, and waterway adequacy (the likelihood of 
water to overtop the bridge) (see fig. 2). If a bridge is found to be 
both structurally deficient and functionally obsolete, it is classified 
as structurally deficient. As a result, about half of all structurally 
deficient bridges are also functionally obsolete.[Footnote 24] 

Figure 2: Key Factors That May Contribute to a Bridge's Classification 
as Functionally Obsolete: 

[See PDF for image] 

This figure is an illustration of key factors that may contribute to a 
bridge's classification as functionally obsolete, as follows: 

Deck geometry: 
The width of the bridge or the number of lanes on the bridge are
inadequate for the average daily traffic it carries. 

Clearance under bridge: 
The under clearance and/or lateral under clearance does not meet
minimum requirements for the railroad or type of highway under
the bridge. 

Source: GAO. 

[End of figure] 

HBP Provides Funding to States to Improve Bridge Conditions: 

Based on bridge classifications, FHWA designates bridges as either HBP- 
eligible or not eligible. Bridges are determined to be eligible if they 
are both deficient and have a sufficiency rating of 80 or less. Bridges 
that are deficient and have a sufficiency rating of 80 or less may be 
eligible for rehabilitation, and bridges that are deficient and have a 
sufficiency rating of less than 50 may be eligible for replacement or 
rehabilitation. All other bridges are designated as not eligible (see 
fig. 3). However, the HBP allows other activities to be funded with 
program funds, regardless of a bridge's eligibility. These activities 
include seismic retrofitting, scour mitigation, and systematic 
preventive maintenance projects.[Footnote 25] Additionally, states may 
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, though a penalty is invoked by reducing 
the state's HBP funds in the succeeding year by the amount transferred. 
Some of these transferred HBP funds may still be spent on bridges and, 
just as HBP funds may be transferred to other Federal-aid highway 
programs, funds from other Federal-aid highway programs may also be 
spent on bridges. 

Figure 3: Process for Designating Bridges as Eligible for HBP Funding: 

[See PDF for image] 

This figure is an illustration of the following information: 

Process for Designating Bridges as Eligible for HBP Funding: 

Bridge classification: 
Not deficient: Bridges with acceptable condition, configuration, and 
design; Or: 
Sufficiency rating: 81-100; equals: 
Eligibility for Highway Bridge Program funds: Not eligible
(classified as not deficient and/or having a higher than 80 sufficiency 
rating). 

Bridge classification: 
Deficient; Structurally deficient; Bridges in poor condition; and: 
Sufficiency rating: 50-80; equals: 
Eligibility for Highway Bridge Program funds: Eligible for 
rehabilitation
(classified as structurally deficient or functionally obsolete with a 
sufficiency rating of 80 or less); 

Bridge classification: 
Deficient; Functionally obsolete; Bridges with poor configuration 
and/or design; and: 
Sufficiency rating: 0-49; equals: 
Eligibility for Highway Bridge Program funds: Eligible for replacement 
or rehabilitation (classified as structurally deficient or functionally 
obsolete with a sufficiency rating of less than 50). 

Source: GAO analysis of FHWA data. 

[End of figure] 

The Safe, Accountable, Flexible, and Efficient Transportation Equity 
Act--A Legacy for Users (SAFETEA-LU), authorized a total of 
approximately $21.6 billion in HBP funds for fiscal years 2005 through 
2009. With three exceptions,[Footnote 26] FHWA apportions, or divides, 
the annually authorized HBP funds among the states according to the HBP 
statutory apportionment process.[Footnote 27] The starting point for 
this apportionment process is the program's needs-based formula. To 
determine states' funding needs for bridge replacement and 
rehabilitation, FHWA first determines each state's total bridge deck 
area in each of four categories: (1) Federal-aid highway bridges 
eligible for replacement, (2) Federal-aid highway bridges eligible for 
rehabilitation, (3) non-Federal-aid highway bridges eligible for 
replacement, and (4) non-Federal-aid highway bridges eligible for 
rehabilitation. Then, depending on the category (i.e., replacement or 
rehabilitation), the total deck area in each category is multiplied by 
either the state's replacement bridge construction unit cost or by the 
state's rehabilitation bridge construction unit cost,[Footnote 28] 
respectively. Finally, the figures for the individual categories are 
totaled to arrive at the state's calculated bridge needs. The national 
bridge need is the sum of each state's calculated bridge needs. Each 
state's percentage of HBP funds is then calculated by dividing the 
state's calculated bridge needs by the national bridge need. 

Three statutory provisions may trigger adjustments to a state's 
apportionment. First, a state's calculated apportionment will be 
adjusted, if necessary, to ensure that each state receives a 
statutorily guaranteed minimum of 0.25 percent or a maximum of 10 
percent of the total annual HBP apportionment.[Footnote 29] Second, if 
a state transferred money out of the HBP in the prior year, the state's 
calculated needs will be reduced by the transferred amount. Third, a 
state's apportionment will be supplemented by additional funding from 
SAFETEA-LU's Equity Bonus Program if the state's calculated 
apportionment is below certain state-specific statutory thresholds. 
[Footnote 30] 

Although states have discretion in determining which bridges they 
choose to spend program funds on, each state is required to spend at 
least 15 percent of its program funds for non-Federal-aid highway 
bridges.[Footnote 31] FHWA, however, may reduce the minimum non- 
Federal-aid highway bridge expenditure requirement after consultation 
with state and local officials, if FHWA "determines that the state has 
inadequate needs to justify the expenditure."[Footnote 32] 

State DOTs Exercise Discretion in Determining How to Use HBP Funds and 
Select Bridge Projects for Funding: 

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. For example, the 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 explained that they do not 
focus on reducing their inventories of deficient bridges and being 
classified as deficient does not always indicate that a bridge is 
unsafe. Instead, state DOTs use a variety of criteria, tools, and 
methods to select among potential bridge projects. For example, 
officials in the six states we visited consider a range of 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. 

States Use HBP Funds to Decrease Their Inventories of Deficient 
Bridges, Address Other State-Identified Bridge Priorities, or Address 
Other Transportation Priorities: 

The HBP gives states three key flexibilities in determining how to use 
their HBP resources, some of which were noted earlier in this report. 
First, the HBP has evolved to allow states to use program funds not 
only for bridge replacement and rehabilitation, but also for seismic 
retrofitting projects, systematic preventive maintenance projects, and 
installation of scour countermeasures on any bridge, regardless of the 
bridge's condition. 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 non-Federal-aid highway 
bridges. Third, states can transfer up to 50 percent of their annual 
HBP apportionment to other core transportation programs. 

In part due to these flexibilities, some states we visited (three of 
the six states) had specific goals to reduce their inventories of 
deficient bridges, while others did not. For example, Texas Department 
of Transportation (TxDOT) officials were highly focused on reducing the 
number of their deficient bridges through two specific goals that they 
established in August 2001--to have 80 percent of Texas bridges 
nondeficient[Footnote 33] by September 2011 and to eliminate all 
structurally deficient "on-system" bridges. (TxDOT's on-system bridges 
are located on the designated state highway system and are administered 
by TxDOT.) TxDOT officials reported progress toward achieving these 
goals; they have increased their nondeficient bridges from 70 to 77 
percent of their total bridge inventory during the period from fiscal 
year 2001 through fiscal year 2006, and they have reduced the number of 
their structurally deficient on-system bridges from 763 to 483 over the 
same time period. The other three states we visited had not established 
such clear goals to reduce their inventories of deficient bridges. For 
example, according to officials at the California Department of 
Transportation (Caltrans), that agency strives to select the 
appropriate project at the right time, regardless of bridge deficiency 
designations. Caltrans's selected projects may address bridge condition 
needs or vulnerabilities such as scour or seismic risk. Accordingly, 
bridge seismic retrofitting projects have received the majority of 
California's HBP funds over the past 10 years. Caltrans officials told 
us that, as a result, the state's progress in reducing the number of 
its deficient bridges has been slow. However, those officials also 
noted that the majority of California's structurally deficient bridges 
are classified as such because of cracks in the bridge deck, which are 
not considered an immediate safety hazard. 

State transportation officials we interviewed highlighted several 
reasons why they may not focus their HBP resources on reducing their 
inventories of deficient bridges: 

* 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. For example, a New York State Department of 
Transportation (NYSDOT) official explained that a bridge may be in 
excellent condition yet not meet current geometric design standards 
and, therefore, may be classified as functionally obsolete. As noted 
earlier in this report, FHWA has also reported that deficient bridges 
are not always unsafe and, if proper vehicle weight restrictions are 
posted and enforced, deficient bridges can continue to serve most 
traffic conditions. 

* The HBP funding formula may create a disincentive to improve 
deficient bridges. Many federal and state transportation officials we 
met with stated that the HBP apportionment formula provides no 
incentive for states to reduce their inventories of deficient bridges 
and may actually provide a disincentive because reducing the number and 
deck area of deficient bridges reduces a state's HBP funding 
eligibility. State DOT officials in four of the six states we visited 
noted this potential disincentive, but most stated that it had no 
impact on their decisions because they have other incentives--such as 
professionalism and accountability to the public--to maintain their 
bridges in good condition. In addition to these reasons, Missouri 
Department of Transportation (MoDOT) officials told us that they are 
not concerned that improving their bridges will lower their annual HBP 
funding apportionment because a loss in apportioned funds could be made 
up with funds from the Equity Bonus Program. 

* 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.[Footnote 34] For example, 
Washington state DOT (WSDOT) officials explained that costly "mega 
projects" that emerge as top priorities through their prioritization 
process may be delayed by a lack of funds. Mega projects are projects 
with an estimated total cost greater than $500 million. For example, 
Washington state is considering several very expensive bridge mega 
projects to improve mobility and safety (the SR 520 floating bridge in 
the Seattle area is estimated to cost $2 billion, the Columbia River 
Crossing is estimated to cost $2 billion, and the Alaskan Way Viaduct 
in downtown Seattle is estimated to cost $4 billion) that would clearly 
exceed the state's available HBP funding (e.g., about $153 million in 
fiscal year 2007). Transportation officials in Washington state and 
other states we visited acknowledged that bridge mega projects such as 
these could easily exhaust a state's entire HBP apportionment for many 
years, potentially to the detriment of all other bridge needs in that 
state. Some officials explained that they are looking to 
congressionally designated funds for these mega projects. Two other 
approaches are also available to fund mega projects. First, because of 
funding limitations, NYSDOT frequently splits large, expensive projects 
into multiyear contracts. This approach helps them complete mega 
projects but also means that a large share of their annual funding is 
programmed before they receive it, thus reducing budgetary flexibility. 
Second, in response to the challenge of its so-called "budget buster" 
bridge projects--costly bridge rehabilitation or replacement projects 
that exceed a transportation district's funding capacity--the Minnesota 
Department of Transportation (MnDOT) has developed a new funding source 
for major bridge projects called the Statewide Bridge Preservation 
Fund. This state funding source will provide 100 percent of the funds 
for "budget buster" bridge replacement projects, with MnDOT districts 
paying all other costs associated with those projects, such as widening 
the highway approaches to the bridges. The Statewide Bridge 
Preservation Fund was approved by MnDOT's Transportation Program 
Committee in January 2006, prior to the I-35W Bridge collapse, but the 
first bridge replacement contract under this program will be let in 
November 2009. 

In addition to determining their overall bridge priorities and goals, 
states exercise discretion in determining how much emphasis they place 
on the improvement of larger urban (often state-owned) bridges versus 
smaller rural (often city or county-owned) bridges. In the four states 
we visited that were able to provide an estimate, the percentage of HBP 
funds apportioned to non-Federal-aid highway bridge owners (generally 
county and city governments) ranged from approximately 15 percent to 55 
percent. Missouri, for example, is attempting to improve the condition 
of its small rural bridges by letting a 30-year contract to address the 
needs of 802 small (an average of 147 feet long), largely rural, mostly 
deficient, state-owned bridges.[Footnote 35] MoDOT plans to use HBP 
funds to cover around 80 percent of the expenses associated with this 
effort, and state funds would cover the remaining 20 percent. 

Finally, states have discretion to spend their HBP funding on other 
state transportation priorities by transferring up to 50 percent of 
their annual HBP funds to other core programs. According to FHWA data, 
from 1998 through 2006, 27 states transferred approximately $2.8 
billion (or about 7 percent of the $37 billion in HBP funds distributed 
over that period) in HBP funds to other Federal-aid highway programs. 
However, FHWA data show that significant funds have flowed toward 
bridges from other programs which, from a national perspective, exceed 
outflows from the HBP. Transfers by the Pennsylvania Department of 
Transportation (PennDOT) account for about half of the total transfers 
from the HBP over this time. PennDOT officials told us that they 
transferred funds out of the HBP to provide more flexibility in funding 
their transportation program. While it is impossible to know the 
effects of PennDOT's transfers on state bridge conditions, PennDOT has 
consistently had the highest or second highest HBP apportionment of all 
states, which reflects the state's consistently poor bridge conditions. 
Caltrans officials also told us that they transferred HBP funds to pay 
for projects that would otherwise not qualify for HBP funding, such as 
seismically retrofitting transit bridges and pedestrian bridges over 
highways. While the HBP apportionment formula is set up to penalize 
states that transfer funds out of the HBP, this penalty does not 
necessarily affect all transferring states because the penalty 
reduction may be made up through Equity Bonus Program funds. For 
example, although PennDOT has transferred a large share of its HBP 
funds to other transportation programs since 1998, it has continued to 
receive the highest or second highest HBP annual apportionment because 
the penalty reduction is made up with Equity Bonus Program funds. 
States also have discretion to spend other federal, state, and local 
funds on bridges, but the extent to which they do so is unknown because 
there are no comprehensive data available on total state and local 
investment in bridges. 

State Departments of Transportation Use a Variety of Criteria, Tools, 
and Methods to Select Among HBP-Eligible Projects: 

State DOTs consider various criteria to prioritize and select bridge 
projects for funding. The HBP requires that funds be shared fairly and 
equitably throughout the state but provides little role for FHWA in 
prioritizing or selecting bridge projects apart from assigning 
sufficiency ratings and establishing eligibility. Partly because of 
this discretion, officials in the six states we visited considered a 
range of criteria, including bridge condition ratings, average daily 
traffic, detour options, funding availability, and local transportation 
priorities. Some states, such as Texas and Missouri, also allow their 
state DOT district offices and local agencies to determine some 
criteria for selecting bridge projects for funding. For example, MoDOT 
officials require MoDOT district offices and local agencies to consider 
bridge conditions, economic benefits, and environmental impacts when 
selecting bridge projects within their region, but also allow each 
region to define independently some of the criteria for evaluating 
proposed bridge projects. Similarly, TxDOT officials stated that their 
25 district offices are allowed to determine some of the criteria for 
selecting bridge projects for funding, and districts' selection 
criteria sometimes include local citizen interests, local politics, and 
environmental and business interests. 

Some states have developed tools and approaches beyond those required 
by the HBP and NBIS--such as bridge management systems, element-level 
inspections, and state-specific condition ratings--to help them gauge 
bridge conditions and further inform their selection of bridge projects 
for funding. For example, all of the states we visited were considering 
adopting, or have already adopted, some form of bridge management 
system. A bridge management system is a system of formal procedures and 
methods for gathering and analyzing bridge data to predict future 
bridge conditions, estimate network maintenance and improvement needs, 
determine optimal policies, and recommend projects and schedules within 
budget and policy constraints. In short, bridge management systems are 
one means by which transportation officials can employ asset management 
principles to help them determine the most efficient way to allocate 
limited HBP resources among competing bridge priorities. For over 5 
years, FHWA has actively encouraged, but has not required, states to 
use bridge management systems, in part, by providing transportation 
officials with relevant training and technical support.[Footnote 36] 
Additionally, for states to use HBP funds for bridge systematic 
preventive maintenance projects, states must use a systematic process, 
such as a bridge management system, to assess the cost-effectiveness of 
the activity in extending the life of the bridge. As of 2007, 43 states 
were, to varying extents, using a comprehensive bridge management 
software system called PONTIS, which FHWA and AASHTO developed to 
assist states in selecting bridge projects. PONTIS stores bridge 
inventory and inspection data, helps officials evaluate the needs of 
each bridge in a network, and recommends projects to include in an 
agency's capital plan to derive the maximum benefit from limited 
transportation funds. 

In addition, all of the states we visited required bridge inspectors to 
gather "element-level" bridge condition data, thereby exceeding NBIS 
requirements. While the NBIS requires bridge inspectors to rate the 
condition of the three major bridge components--the superstructure, 
substructure, and deck--an element-level inspection requires a more 
detailed breakdown of these bridge components. Instead of the NBIS's 
single superstructure rating, element-level inspection requires 
individual condition assessments for girders, floor beams, pins, and 
hangers, for example. Element-level data provide a more detailed 
picture of a bridge's overall condition. Some state DOT officials said 
that the more detailed data provided by element-level inspections 
(rather than the basic federally required inspection data) allowed them 
to more precisely evaluate bridge conditions and better select bridge 
projects for funding. 

Finally, 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, NYSDOT requires bridge inspectors to 
rate bridge components using the federal condition rating scale and 
also use a New York-specific condition rating scale to rate all New 
York State defined bridge elements. New York's scale expresses the 
overall bridge condition in a single number, which is calculated by 
rating up to 47 bridge elements and weighting them according to their 
importance to the structure. New York officials told us that their more 
nuanced condition rating system is better than the federal rating for 
prioritizing bridge work. Caltrans officials also use a state scale, 
the California Bridge Health Index, which they developed to help them 
prioritize bridge projects on the state highway system. The Bridge 
Health Index is a single-number assessment of a bridge's condition 
based on the bridge's economic worth, determined from the results of 
element-level inspections. Unlike FHWA's sufficiency rating, the Health 
Index provides insight into the structural condition of a bridge 
without regard to the bridge's functional adequacy. Caltrans officials 
stated that they have discovered many management applications for the 
Bridge Health Index, including performance measurement, resource 
allocation, budget management, and selection of the best option for 
bridge preservation. 

State DOTs also 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. Additionally, two state DOTs we visited 
prioritize all of their bridge projects (regardless of who owns the 
bridges) in one process, while others have separate processes for state 
and locally owned bridge projects. WSDOT, for example, has a highly 
centralized process for prioritizing state-owned bridge projects but 
uses a separate method--a Bridge Replacement Advisory Committee made up 
of city and county representatives--to prioritize and select non state 
bridge projects for HBP funding. MoDOT has a mixed process, in which 
staff prioritize "major" bridge projects--bridges with an overall 
length of 1,000 feet[Footnote 37]--centrally and allow "nonmajor" 
bridge and road projects to be prioritized and selected by MoDOT 
district offices in collaboration with metropolitan planning 
organizations, regional planning commissions, and other stakeholders. 
To standardize these district-level processes across the state, MoDOT 
has developed a statewide "Framework for Transportation Planning and 
Decision-Making," which delineates a standardized point system to score 
and rate potential bridge projects, but which also allows the relevant 
MoDOT district office and local agencies to determine 5 to 25 percent 
of the scoring value. Finally, PennDOT follows a more decentralized, 
collaborative process. PennDOT officials explained that although they 
provide their 11 district offices with a ranking of their statewide 
bridge priorities, their final prioritization of all bridge projects is 
carried out by Pennsylvania's 23 planning organizations (metropolitan 
planning organizations and rural planning organizations) and their 
corresponding PennDOT district offices. 

Available Data Indicate That the Overall Condition of the Nation's 
Bridges Has Improved, but the Impact of the HBP Is Difficult to 
Determine: 

From 1998 through 2007, bridge conditions, as measured by deficiency 
status and the average sufficiency rating of all bridges in the NBI, 
improved nationwide, but it is difficult to determine the impact of the 
HBP. Over this period, the number of deficient bridges declined by 
almost 12 percent and the number of structurally deficient bridges 
decreased by 22 percent. In addition, the average bridge sufficiency 
rating improved slightly. Improvements were most notable in bridges 
owned by local agencies and on rural routes. However, because HBP 
funding is only a share of total funding for bridges, available bridge 
condition measures capture only a part of the impact of the HBP, and 
because NBI data do not readily permit the tracking of changes in the 
condition of a group of bridges across time, it is difficult to 
determine the impact of the HBP. 

Overall Bridge Condition Has Improved since 1998: 

Data indicate that the total number of deficient bridges--including 
structurally deficient and functionally obsolete bridges--has decreased 
over the last 10 years, even as the total number of bridges has 
increased. From 1998 to 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. 4). 

Figure 4: Trends in Numbers of Bridges and Deficient Bridges, 1998 
through 2007: 

[See PDF for image] 

This figure is a combination vertical bar and line graph depicting the 
following data: 

Year: 1998; 
All bridges: 583,401; 
Deficient bridges: 172,683. 

Year: 1999; 
All bridges: 585,928; 
Deficient bridges: 170,126. 

Year: 2000; 
All bridges: 587,719; 
Deficient bridges: 167,639. 

Year: 2001; 
All bridges: 590,151; 
Deficient bridges: 165,114. 

Year: 2002; 
All bridges: 591,241; 
Deficient bridges: 162,862. 

Year: 2003; 
All bridges: 592,279; 
Deficient bridges: 160,813. 

Year: 2004; 
All bridges: 594,097; 
Deficient bridges: 158,363. 

Year: 2005; 
All bridges: 595,664; 
Deficient bridges: 156,376. 

Year: 2006; 
All bridges: 597,498; 
Deficient bridges: 154,112. 

Year: 2007; 
All bridges: 599,817; 
Deficient bridges: 152,317. 

Increase in all bridges, 1998-2007: 16,416; 
Decrease in deficient bridges, 1998-2007: 20,366. 

Source: GAO analysis of FHWA data. 

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

[End of figure] 

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. 5). 
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 
characteristics 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. However, because 
functionally obsolete bridges that are also structurally deficient are 
recorded in the NBI as structurally deficient, data may understate the 
improvement in functionally obsolete bridges. Likewise, if a 
structurally deficient bridge becomes functionally obsolete, this 
change would not be reflected as an increase in the number of 
functionally obsolete bridges. 

Figure 5: Number of Structurally Deficient and Functionally Obsolete 
Bridges, 1998 through 2007: 

[See PDF for image] 

This figure is a multiple line graph depicting the following data: 

Year: 1998; 
Structurally deficient bridges: 93,118; 
Functionally deficient bridges: 79,565. 

Year: 1999; 
Structurally deficient bridges: 88,184; 
Functionally deficient bridges: 81,942. 

Year: 2000; 
Structurally deficient bridges: 86,721; 
Functionally deficient bridges: 80,918. 

Year: 2001; 
Structurally deficient bridges: 83,631; 
Functionally deficient bridges: 81,483. 

Year: 2002; 
Structurally deficient bridges: 81,297; 
Functionally deficient bridges: 81,565. 

Year: 2003; 
Structurally deficient bridges: 79,807; 
Functionally deficient bridges: 81,006. 

Year: 2004; 
Structurally deficient bridges: 77,772; 
Functionally deficient bridges: 80,591. 

Year: 2005; 
Structurally deficient bridges: 75,948; 
Functionally deficient bridges: 80,428. 

Year: 2006; 
Structurally deficient bridges: 73,796; 
Functionally deficient bridges: 80,316. 

Year: 2007; 
Structurally deficient bridges: 72,519; 
Functionally deficient bridges: 79,798. 

Source: GAO analysis of FHWA data. 

[End of figure] 

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. 
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. 

Most of the improvements in bridge conditions over this period are 
attributable to improvements in bridges that are owned by local 
agencies and bridges on rural routes. The condition of locally owned 
bridges and bridges on rural routes have steadily improved since 1998, 
which may be attributable to the federal bridge program requirement-- 
under HBP and some of its predecessor programs--that states spend a 
minimum amount of their apportionment on non-Federal-aid highway 
bridges. 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. 6). 

Figure 6: Number of Deficient Bridges, by Bridge Owner, 1998 through 
2007: 

[See PDF for image] 

This figure is a multiple line graph depicting the following data: 

Year: 1998; 
Locally owned deficient bridges: 99,492; 
State owned deficient bridges: 70,066. 

Year: 1999; 
Locally owned deficient bridges: 96,642; 
State owned deficient bridges: 69,591. 

Year: 2000; 
Locally owned deficient bridges: 95,405; 
State owned deficient bridges: 68,962. 

Year: 2001; 
Locally owned deficient bridges: 93,084; 
State owned deficient bridges: 68,613. 

Year: 2002; 
Locally owned deficient bridges: 91,126; 
State owned deficient bridges: 68,377. 

Year: 2003; 
Locally owned deficient bridges: 89,785; 
State owned deficient bridges: 67,994. 

Year: 2004; 
Locally owned deficient bridges: 87,694; 
State owned deficient bridges: 67,638. 

Year: 2005; 
Locally owned deficient bridges: 85,572; 
State owned deficient bridges: 67,759. 

Year: 2006; 
Locally owned deficient bridges: 83,568; 
State owned deficient bridges: 67,583. 

Year: 2007; 
Locally owned deficient bridges: 82,101; 
State owned deficient bridges: 67,232. 

Source: GAO analysis of FHWA data. 

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

[End of figure] 

Although the number of deficient rural bridges declined from 1998 
through 2007, the number of deficient urban bridges increased.[Footnote 
38] For example, from 1998 to 2007, the number of deficient rural 
bridges decreased by about 19 percent, from 130,910 to 106,209. 
[Footnote 39] During that same period, however, the number of deficient 
urban bridges increased by about 11 percent, from 41,659 to 46,086 (see 
fig. 7). 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 7: Number of Deficient Bridges, by Rural and Urban 
Classification, 1998 through 2007: 

[See PDF for image] 

This figure is a multiple line graph depicting the following data: 

Year: 1998; 
Rural deficient bridges: 130,910; 	
Urban deficient bridges: 41,659. 

Year: 1999; 
Rural deficient bridges: 128,014; 
Urban deficient bridges: 42,032. 

Year: 2000; 
Rural deficient bridges: 125,520; 
Urban deficient bridges: 42,031. 

Year: 2001; 
Rural deficient bridges: 122,944; 
Urban deficient bridges: 42,088. 

Year: 2002; 
Rural deficient bridges: 120,608; 
Urban deficient bridges: 42,176. 

Year: 2003; 
Rural deficient bridges: 118,535; 
Urban deficient bridges: 42,200. 

Year: 2004; 
Rural deficient bridges: 115,851; 
Urban deficient bridges: 42,482. 

Year: 2005; 
Rural deficient bridges: 112,341; 
Urban deficient bridges: 43,990. 

Year: 2006; 
Rural deficient bridges: 109,201; 
Urban deficient bridges: 44,875. 

Year: 2007; 
Rural deficient bridges: 106,209; 
Urban deficient bridges: 46,086. 

Source: GAO analysis of FHWA data. 

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

[End of figure] 

It Is Difficult to Determine the Impact of the HBP Due to Lack of 
Comprehensive Information on State and Local Spending, Expansion of 
Bridge Project Eligibility, and Limitations in NBI Data: 

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. For 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. Also, 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. 
Furthermore, neither of these two FHWA data sources on bridge spending 
includes noncapital activities funded by the HBP, such as systematic 
preventive maintenance, anti-icing and deicing applications, and 
painting. In addition, while two of the state DOTs we visited had data 
on state bridge spending, none was able to provide comprehensive data 
on total state and local investment in bridges. This lack of 
comprehensive information on state and local spending makes it 
impossible to (1) distinguish the impact of HBP funding from other 
funding to improve bridge conditions and (2) determine the extent to 
which states are substituting increased HBP funding for state and local 
funds that they would otherwise have spent on bridges. While there is 
no state-by-state data on total state and local spending on bridges, 
some officials we interviewed estimated that, in their states, such 
spending 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. Federal funding for transportation programs, 
including the HBP, has increased in recent years, but it is difficult 
to determine the impact of the increased federal investment on state 
and local agencies' decisions to invest in bridges. Our previous work 
has shown that although the 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.[Footnote 
40] More specifically, 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. 

The impact of the HBP is also difficult to measure because available 
bridge condition data capture only part of the total impact of the HBP. 
As discussed earlier, states can and do use HBP funds for a variety of 
activities, in addition to rehabilitating and replacing their deficient 
bridges. 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 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. 

Another difficulty in determining the impact of the 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 either 
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. The average age of bridges currently in the 
NBI is approximately 35 years, the average age of bridges with a 
sufficiency rating of 80 or less is 39 years (a deficient bridge with 
this rating becomes eligible for rehabilitation), and the average age 
of bridges with a sufficiency rating less than 50 is 53 years (a 
deficient bridge with this rating becomes eligible for replacement). 
[Footnote 41] This suggests that as the age of bridges in this group 
rises, so will the number of HBP-eligible bridges. As a result, states 
and local agencies may see a spike in their need for bridge 
rehabilitation and replacement funding over the next 15 years (see 
appendix II for additional analysis of bridge trends). 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 Lacks Focus, Performance Measures, and Sustainability: 

The current program, while generally helping to improve bridge 
conditions, does not have goals and performance measures that align 
with federal funding. In this way, the program mirrors the challenges 
of the overall federal surface transportation program. Even though the 
goal of improving deficient bridges may seem clear and performance- 
oriented, the structure of the program provides little linkage or 
assurance of any direct impact on either the safety of the nation's 
bridges or attention to national problems that transcend individual 
states, such as freight mobility and congestion. Additionally, the 
goals of the program have broadened to include other activities, and 
the federal apportionment formula generally provides funds to states 
without reference to achieving specific outcomes. 

While some have called for increased funding for the HBP as one 
possible response to the concerns raised by the I-35W bridge collapse, 
we believe that there is merit in evaluating the performance and impact 
of the HBP to ensure effectiveness, particularly in light of the 
breadth of current and future demands that will likely be placed on 
limited federal funding. Bridge infrastructure, like most of the 
nation's physical infrastructure, is under strain. In addition, steady 
increases in road usage, congestion, and the aging of the nation's 
bridges will likely continue to present challenges in the future. 
[Footnote 42] Moreover, the Highway Trust Fund, which provides the 
funding for the HBP, faces an imbalance of revenues and expenditures 
and other threats to its long-term sustainability. Given the nation's 
infrastructure challenges and the federal government's fiscal outlook, 
we have called for a fundamental re-examination of government programs. 
We have found that many current transportation programs do not 
effectively address identified transportation challenges, such as 
freight bottlenecks and growing congestion. Addressing these challenges 
requires strategic approaches, effective tools and programs, and 
coordinated solutions involving all levels of government and the 
private sector.[Footnote 43] 

We have identified several key principles that could be informative as 
policymakers assess federal surface transportation programs, including 
the HBP. We developed these principles based on prior analyses of 
existing surface transportation programs, as well as a body of work 
that we have developed for Congress, including our High-Risk and 
Performance and Accountability reports.[Footnote 44] The principles can 
serve to help refocus federal transportation programs to improve the 
effectiveness of the federal investment in transportation, meet the 
nation's transportation needs, and ensure a sustainable commitment to 
transportation infrastructure.[Footnote 45] We examined the HBP to 
determine the extent to which it is aligned with these principles and 
identify opportunities to improve its performance and sustainability 
(see fig. 8). 

Figure 8: Application of Key Principles to the HBP: 

[See PDF for image] 

This figure is an illustration of the application of key principles to 
the HBP, as follows: 

Key principle: Create well-defined goals and roles based on identified 
areas of federal interest; 
Critical question: Does the HBP have clear goals and a defined federal 
role? What is the federal interest in bridges?
Assessment of HBP: Goals of the HBP are numerous and have expanded from
focusing on the improvement of deficient bridges to other areas such as 
seismic retrofitting. As a result, the federal interest has been 
expanded to potentially include almost any bridge. Additionally, there 
is no clear federal role in the HBP and state and local governments 
have broad discretion in allocating HBP funds. 

Key principle: Incorporate performance and accountability into funding 
decisions; 
Critical question: Does the HBP have performance measures which are 
linked to federal funding? 
Assessment of HBP: The condition of bridges has improved overall, but 
there is no clear tie between program funding or activities and the 
degree of progress attained. Although the HBP formula is based on 
bridge deficiency status and sufficiency ratings, this may not be the 
best proxy for bridge safety or risk, and there are several other 
activities that HBP funds can be spent on. 

Key principle: Employ best tools and approaches to help improve return 
on investment; 
Critical question: Do HBP funds encourage state and local governments to
maximize the safety or mobility benefit of their investment and to 
invest their own resources? 
Assessment of HBP: The program lacks tools to determine the effects of 
federal investment in bridges. Bridge management systems, an optional 
tool for bridge owners, provide a useful approach for prioritizing 
projects and making funding decisions. 

Key principle: Ensure fiscal sustainability; 
Critical question: Are HBP expenditures affordable and sustainable in 
the long term? 
Assessment of HBP: Program sustainability remains a challenge due to 
the aging bridge infrastructure, lack of assurance about the impact of
federal HBP funding, and the nation’s fiscal challenges. 

Source: GAO. 

[End of figure] 

Program's Statutory Goals Are Not Focused on a Clearly Identified 
Federal Interest: 

The expansion of the HBP's purpose from improving deficient bridges to 
supporting seismic retrofitting, systematic preventive maintenance, and 
many other projects, has greatly expanded the universe of eligible 
bridges. As a result, the federal interest has been expanded to 
potentially include almost any bridge in the country. Our previous work 
has emphasized the importance of identifying clear areas of federal or 
national 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 program 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 it could still be better incorporated 
into the goals of the program. For example, the DOT's Inspector General 
has proposed that FHWA develop a data-driven, risk-based approach to 
bridge oversight to better identify and target those structurally 
deficient bridges most in need of attention. 

Once the federal interest in bridges is clearly defined, policymakers 
can clarify the goals for federal involvement and define the federal 
government's role in working toward goals that more directly address 
national transportation priorities. The federal role should be defined 
in relation to the roles of state and local governments, regional 
entities, and the private sector. Where the national interest is 
greatest, the federal government may play a more direct role in setting 
priorities and allocating resources, as well as fund a higher share of 
program costs. Conversely, where the national interest is less evident-
-for example, where the economic benefits are more locally focused or 
there are varying regional preferences--state and local governments and 
others could be expected to assume more responsibility. 

Once the national interest has been defined, our principles call for 
basing the federal share of bridge projects on the level of federal 
interest. For example, the federal interest may be greater for Federal- 
aid highway bridges, whereas state and local governments may have 
greater interest in non-Federal-aid highway bridges and the funding 
shares could reflect those relative interests. 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. Under the current HBP 
structure, the federal share is generally 80 percent of the total 
project costs. The cost sharing arrangement should be structured so 
that the level and share of federal funding reflects the benefits the 
nation receives from investment in a bridge project; however, in 
reality, this cost sharing appears to reflect historical levels of 
funding for many surface transportation programs without reference to 
whether the cost share should vary by project or whether state and 
local governments could assume more responsibility. 

Alternatively, HBP funds could be directed to a greater degree to 
bridges in the national interest by re-establishing the cap on or 
reducing the minimum requirement for states' spending of federal funds 
for non-Federal-aid highway bridges. Since 1978, a minimum of each 
state's apportionment was to be spent on non-Federal-aid highway 
bridges. Until the enactment of SAFETEA-LU, there was also a maximum, 
35 percent, that could be spent on non-Federal-aid highway bridges. 
SAFETEA-LU eliminated the ceiling, opening up the entire state HBP 
apportionment to spending on non-Federal-aid highway bridges. 
Furthermore, the fact that bridge condition improvements are more 
heavily concentrated in local and rural bridges, rather than state- 
owned urban bridges, may reflect states' efforts to adhere to this HBP 
requirement, despite arguably greater federal interest in urban and 
larger bridges that are likely to carry more traffic and interstate 
commerce. 

No Clear Tie between Program's Funding and Performance: 

The HBP apportionment formula is not linked to the states' performance 
in reducing their inventories of deficient bridges. Because, as 
discussed earlier, the formula is based on a calculation of states' 
portion of the total cost of needed repairs to deficient bridges, it 
does not consider a state's efforts or effectiveness in reducing its 
inventory of deficient bridges or controlling costs. Additionally, 
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. As a result, the incentive to improve return on investment-
-the public benefits gained from public resources expended--is reduced. 
Further, a bridge's deficiency status and sufficiency rating may not be 
the best proxy for bridge safety or risk. For example, states we 
visited and officials we spoke with identified other priorities for 
bridge projects, such as seismic retrofitting, that are a greater 
safety concern for their bridge programs. Also, because the 
apportionment formula is based on eligible deficient bridge deck area, 
as states reduce the number of deficient bridges, they could become 
eligible for less HBP funding, which has created a potential 
disincentive for states to eliminate deficient bridges. However, state 
transportation officials we interviewed indicated that other factors, 
such as accountability to the public, responsibility for good 
management of limited resources, and professional integrity provide 
incentives for them to maintain and improve bridges. 

Our work has shown that an increased focus on performance and 
accountability for results can help the federal government target 
resources to programs that best achieve intended outcomes and national 
priorities. Tracking specific outcomes that are clearly linked to clear 
program goals provides a strong foundation for holding grant recipients 
responsible for achieving federal objectives and measuring overall 
program performance. These principles indicate that, for the HBP, 
developing specific performance measures could help make the program 
more outcome-oriented. For example, if maintaining or improving 
mobility were established as a program goal, measures could be used to 
track outcomes of federal funding for bridge improvements, such as a 
reduction in the number of bridge closures or weight restrictions on 
highly used routes. Furthermore, directly linking the allocation of 
resources to program outcomes would increase the focus on performance 
and accountability for results. For example, modifying the 
apportionment formula to link funding with improvements in bridge 
conditions would create incentives for states to focus on results. 

The Program Lacks Tools to Determine the Effectiveness of the Federal 
Investment: 

Our work has shown that the effectiveness of any federal program can be 
increased by promoting and facilitating the use of the best tools and 
approaches to improve results and emphasize return on investment. For 
example, we have found that the use of certain tools and approaches, 
such as economic analysis comparing projects, improved management of 
existing capacity, and public-private partnerships, can improve surface 
transportation program results and return on investment. According to 
FHWA, state, and local transportation officials we spoke with, bridge 
management systems, such as PONTIS, also provide a useful approach for 
prioritizing projects and making funding decisions. Although the use of 
management systems is optional for bridge owners, almost all states 
employ some type of bridge management system, and all of the states we 
visited had implemented or considered implementing bridge management 
systems to help make project selection decisions. Because these systems 
analyze data to help states identify and prioritize needs, their use 
could help the HBP more directly address national priorities. 

A competitive project selection process is another approach that our 
work has shown can improve results and return on investment. Such a 
process allows agencies to direct program funds to achieve national 
interests and goals. We have previously reported that a competitive 
selection process with clearly defined selection criteria can help 
identify projects that maximize the public benefits in the federal 
interest and hold grant recipients accountable for results.[Footnote 
46] Applying this approach to the HBP would allow FHWA to better target 
federal funding toward projects that achieve identified national 
interests and goals. Potential formula elements could include a 
bridge's safety risk level, traffic levels, or some other measure of 
importance on a national level. 

Given the projected growth in federal deficits, constrained state and 
local budgets, and looming Social Security and Medicare spending 
commitments, the resources available for discretionary programs will be 
more limited--making it imperative to maximize the national public 
benefits of any federal investment through a rigorous examination of 
the use of such funds. Exploring and using best tools and approaches, 
such as the ones we describe here, could help the HBP more directly 
focus on national priorities and provide a more informed process for 
prioritizing and selecting bridge projects for funding. 

Program Sustainability Remains a Challenge: 

The nation's overall fiscal imbalance makes it implausible to improve 
the HBP merely by increasing federal contributions. The sustainability 
of the HBP and other surface transportation programs depends not only 
on the level of federal funding but also on the allocation of funds to 
projects that provide the best return on investment and address 
national transportation priorities.[Footnote 47] The anticipated 
deterioration of the nation's bridges--and the declining purchasing 
power of currently available funding for bridge construction, repair, 
and maintenance--present challenges to the sustainability of the HBP, 
particularly in light of the long-term pressures on the Highway Trust 
Fund and the governmentwide problem of fiscal imbalance. With the 
expansion of HBP goals, any bridge is potentially eligible for some 
degree of federal HBP funding, and the discretion that the HBP gives 
states in determining priorities and selecting bridge projects for 
funding has led to varying national bridge priorities from state to 
state. Without links between federal goals and performance, the HBP's 
effectiveness is unknown. Given the future fiscal challenges facing the 
nation, the effectiveness of the federal investment can be improved by 
better targeting the use and impact of such funds. 

The aging of the nation's bridges, discussed earlier in this report, 
coupled with the declining purchasing power of currently available 
funding and recent growth in construction costs, presents specific 
sustainability challenges for the HBP. Although transportation revenues 
have continued to increase in nominal terms, the federal and state 
motor fuel tax rates have not kept up with inflation. As a result, 
according to DOT and FHWA data, the purchasing power in real terms of 
revenues generated by federal and state motor fuel tax rates has been 
declining since 1990.[Footnote 48] Furthermore, the cost of building 
and maintaining bridges has increased steadily over the last few years, 
at a rate that exceeds inflation. In particular, the price of 
construction materials has increased significantly in the last few 
years because of rising concrete and steel prices. 

According to our work, two tools that could improve the sustainability 
of the HBP are a maintenance-of-effort requirement for grantee spending 
and tolling. First, the potential substitution of federal funds for 
state and local funds under the HBP and other federal transportation 
programs may be reduced by establishing a maintenance-of-effort 
requirement, whereby state or local grantees would be required to 
maintain their own level of funding in order to receive federal funds. 
Such a requirement could discourage states and local governments from 
substituting federal support for funds they themselves would otherwise 
have spent. Secondly, our work has shown that removing barriers to, or 
even promoting, tolling can lead to more efficient management of 
existing infrastructure and capacity. For example, the tolling of 
bridges could not only raise funds for bridge maintenance and repairs 
but potentially improve the performance and reliability of the bridge. 
The introduction of tolling that varies with time of day or congestion 
could increase the speed of traffic, increase capacity, and provide new 
revenues and potentially leverage existing revenue sources.[Footnote 
49] For example, Caltrans owns and operates seven toll bridges in the 
San Francisco Bay area where toll funds are used for bridge-related 
transportation priorities, including bridge replacement and 
rehabilitation projects, improvements in critical traffic bottlenecks, 
and seismic retrofitting projects. 

Conclusions: 

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. 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 
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 have 
developed 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. 

Recommendation for Executive Action: 

To improve the focus, performance, and sustainability of the HBP, we 
recommend that the Secretary of Transportation work with Congress to: 

* 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: 

* review and evaluate HBP funding mechanisms to align funding with 
performance and support a targeted and sustainable federal bridge 
program. 

Agency Comments: 

We provided a draft of this report to DOT for review and comment prior 
to finalizing the report. DOT officials said that they generally agreed 
with the findings in the report and they provided technical comments, 
which we incorporated, 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.[Footnote 
50] 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 re- 
examination of those programs and help assess options for restructuring 
the entire federal surface transportation program.[Footnote 51] 

We are sending copies of this report to the appropriate congressional 
committees and to the Secretary of Transportation. We will also make 
copies available to others upon request. In addition, this report will 
be available at no charge on the GAO Web site at [hyperlink, 
http://www.gao.gov]. 

If you or your staffs have any questions about this report, please 
contact me at (202) 512-2834 or siggerudk@gao.gov. Contact points for 
our Offices of Congressional Relations and Public Affairs may be found 
on the last page of this report. GAO staff that made key contributions 
to this report are listed in appendix III. 

Signed by: 

Katherine Siggerud: 
Managing Director, Physical Infrastructure Issues: 

[End of section] 

Appendix I: Scope and Methodology: 

To determine how the Highway Bridge Program (HBP) identifies and 
addresses the condition of the nation's highway bridges, we reviewed 
relevant legislation, program documents, and the Federal Highway 
Administration's (FHWA's) historical data on the apportionment of HBP 
funds among states, and we interviewed FHWA officials. One key 
information source was FHWA's draft Bridge Program Manual, which is a 
collection of all of the basic program and technical information needed 
by FHWA bridge engineers to perform their duties. In addition to 
reviewing documents, we met with senior FHWA bridge officials in 
Washington, D.C., and division offices to learn how bridges are 
inspected, inventoried, and classified and how FHWA apportions HBP 
funds to states. 

To determine how states 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 conducted 
interviews with federal, state, and local transportation officials and 
visited six bridges. We chose these six states based on their 
relatively high levels of HBP funding, large bridge inventories, and 
large structurally deficient bridge inventories. Of the states meeting 
these criteria, we selected states that varied on key characteristics 
of interest, including the proportion of state versus locally owned 
bridges, whether the state has transferred funds out of the HBP since 
2000, and officials' comments on any notable or innovative state bridge 
or inspection programs. Although the limited number of site visits 
means that we are not able to generalize our results to all states, we 
chose this methodology because, given the impracticality of visiting 
all states, in-depth information from six states with relatively high 
levels of HBP funding, large bridge inventories, and high numbers of 
structurally deficient bridges allows us to report on how those states 
with the most at stake have used federal bridge funding and implemented 
the program. During these site visits, we interviewed FHWA division 
office staff, state transportation department officials, and local 
(city and county) bridge owners to learn how states use their HBP funds 
and select specific bridge projects for funding and what, if any, role 
FHWA officials had in these decisions. In addition, we visited six 
bridges, accompanied by state and local transportation officials, in 
four of these states to learn more about how the National Bridge 
Inspection Program (NBIP) and HBP affect bridge inspection and 
management decisions. Table 1 provides information on some key bridge 
characteristics and HBP funding in each state that we visited. 

Table 1: Information on Bridge Characteristics and HBP Funding in 
States Selected for Site Visits, Fiscal Year 2007: 

State: California; 
HBP funding apportionment: $407,727,157; 
Total number of bridges: 24,189; 
Number of structurally deficient bridges: 3,140. 

State: Missouri; 
HBP funding apportionment: $154,835,091; 
Total number of bridges: 24,059; 
Number of structurally deficient bridges: 4,432. 

State: New York; 
HBP funding apportionment: $468,357,103; 
Total number of bridges: 17,361; 
Number of structurally deficient bridges: 2,128. 

State: Pennsylvania; 
HBP funding apportionment: $479,847,760; 
Total number of bridges: 22,325; 
Number of structurally deficient bridges: 5,802. 

State: Texas; 
HBP funding apportionment: $200,596,088; 
Total number of bridges: 50,266; 
Number of structurally deficient bridges: 2,186. 

State: Washington; 
HBP funding apportionment: $153,284,192; 
Total number of bridges: 7,686; 
Number of structurally deficient bridges: 401. 

Source: GAO analysis of FHWA data. 

[End of table] 

To determine what available data indicate about the condition of the 
nation's bridges and the impact of the HBP, we analyzed data in FHWA's 
National Bridge Inventory (NBI), reviewed relevant legislation and 
program documents, and interviewed federal and state transportation 
officials. We analyzed NBI data from 1998 through 2007 to determine the 
current condition of the nation's bridges and 10-year trends in the 
number, size, condition, age, ownership, and characteristics of bridges 
nationwide. Based on reviews of data documentation, interviews with 
relevant officials, and tests for reasonableness, we determined that 
the data we used were sufficiently reliable for the purposes of our 
study. The relevant literature we reviewed included federal 
legislation, regulations, and policies related to the HBP. Finally, we 
interviewed FHWA division office staff and state DOT officials to learn 
how agencies decide to use HBP funds, track total spending on bridges, 
and measure their performance. 

To determine the extent to which the HBP aligns with principles 
established in our prior work to guide the re-examination of surface 
transportation programs, we compared HBP practices to our key 
principles involving identifying clear federal goals and roles, 
incorporating performance and accountability into funding decisions, 
using best tools and practices, and ensuring fiscal sustainability. In 
addition, to identify opportunities to improve the HBP, we analyzed 
information from our interviews with federal and state transportation 
officials, recent DOT Office of Inspector General testimony, 
Congressional Research Service reports, legislation proposed in 
Congress, and our prior work on related issues. 

We conducted this performance audit 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 provides a reasonable basis for 
our findings and conclusions based on our audit objectives. 

[End of section] 

Appendix II: Bridge Maintenance Responsibility, Type of Use, and Age: 

The NBI provides information on bridges in the United States, including 
which level of government is responsible for maintaining them, their 
level of use, and age. The following analyses address the extent of 
federal, state or local governments' responsibility for bridge 
reconstruction and maintenance, the extent to which bridges are on the 
National Highway System (NHS), and challenges associated with the aging 
of bridges.[Footnote 52] 

Bridge Maintenance Responsibility: 

Bridges vary significantly in their size and use, including daily 
traffic. As a result, the reconstruction needs and maintenance 
responsibilities also vary. For example, some bridges are relatively 
small and have relatively light use, such as a county highway bridge, 
while other bridges are significantly larger and carry high levels of 
interstate highway traffic. Bridge deck area, which provides insight 
into the relative size of a bridge, and average daily traffic (ADT), 
which indicates the number of vehicles using each bridge, can both be 
useful indicators of reconstruction needs, maintenance responsibility, 
and costs associated with their ownership.[Footnote 53] Therefore, 
analyses of bridge ownership responsibilities are more complete when 
they consider the size of the bridge deck area and ADT, as well as the 
number of bridges owned. 

As shown in figure 9, number of bridges owned is fairly evenly split 
between state (48 percent) and local government agencies (51 percent). 
However, state agencies are responsible for 76 percent of the nation's 
bridge deck area and 87 percent of the ADT crossing bridges. This 
indicates that while state and local agencies are responsible for 
maintaining about the same number of bridges, the states have 
significantly larger bridges to maintain and the majority of vehicle 
traffic uses the state-maintained bridges. 

Figure 9: Bridge Inventory Count, Deck Area, and ADT, by Owner, 2007: 

[See PDF for image] 

This figure contains three pie-charts which depict the following data: 

Bridge Inventory Count, Deck Area, and ADT, by Owner, 2007: 

Count: 
Local: 51%; 
State: 48%; 
Federal: 1.3%; 
Other: 0.3%. 

Deck area: 
State: 76%; 
Local: 23%; 
Federal: 0.7%; 
Other: 0.5%. 

ADT:
State: 87%; 
Local: 12%; 
Federal: 0.2%; 
Other: 0.2%. 

Source: GAO analysis of FHWA data. 

[End of figure] 

Extent of Bridges on National Highway System: 

Analysis of the NHS classification provides one means of identifying 
bridges that may have national significance in terms of the national 
economy, defense, and mobility. As shown in figure 10, NHS bridges 
constitute 19 percent of all bridges but account for 49 percent of all 
bridge deck area and carry 71 percent of the average daily traffic 
crossing bridges in the United States. While only one-fifth of bridges 
are on the NHS, they account for almost half of the deck area to be 
maintained and can affect mobility significantly if they are not 
adequately maintained. 

Figure 10: Bridge Inventory Count, Deck Area, and ADT, by NHS 
Classification, 2007: 

[See PDF for image] 

This figure contains three pie-charts which depict the following data: 

Bridge Inventory Count, Deck Area, and ADT, by NHS Classification, 
2007: 

Count: 
Non-NHS: 81%; 
NHS: 19%. 

Deck area: 
Non-NHS: 51%; 
NHS: 49%. 

ADT:
Non-NHS: 29%; 
NHS: 71%. 

Source: GAO analysis of FHWA data. 

Note: NHS classification is unknown for 115 of the 599,817 bridges in 
the United States. 

[End of figure] 

Challenges Associated with Aging of Bridges: 

Addressing the scope of deficient bridges will likely be a growing 
challenge as larger numbers of bridges built after 1950 reach the age 
when they may need to be rehabilitated or replaced. The number of 
bridges constructed in the United States increased greatly beginning in 
the 1950s (see fig. 11), and these bridges were also generally larger 
than bridges built in earlier decades. For example, figure 12 shows how 
the total square feet of bridge deck being constructed significantly 
increased starting in 1950. 

Figure 11: Number of Bridges, by Year Built, 2007: 

[See PDF for image] 

This figure is a vertical bar graph depicting the following data: 

Year: Before 1900; 
Number of bridges: 1,975. 

Year: 1900-1904; 
Number of bridges: 7,056. 

Year: 1905-1909; 
Number of bridges: 2,044. 

Year: 1910-1914; 
Number of bridges: 3,879. 

Year: 1915-1919; 
Number of bridges: 3,974. 

Year: 1920-1924; 
Number of bridges: 8,913. 

Year: 1925-1929; 
Number of bridges: 13,144. 

Year: 1930-1934; 
Number of bridges: 23,892. 

Year: 1935-1939; 
Number of bridges: 26,618. 

Year: 1940-1944; 
Number of bridges: 16,451. 

Year: 1945-1949; 
Number of bridges: 14,750. 

Year: 1950-1954; 
Number of bridges: 31,344. 

Year: 1955-1959; 
Number of bridges: 42,105. 

Year: 1960-1964; 
Number of bridges: 54,410. 

Year: 1965-1969; 
Number of bridges: 54,178. 

Year: 1970-1974; 
Number of bridges: 46,554. 

Year: 1975-1979; 
Number of bridges: 39,659. 

Year: 1980-1984; 
Number of bridges: 37,588. 

Year: 1985-1989; 
Number of bridges: 42,031. 

Year: 1990-1994; 
Number of bridges: 42,091. 

Year: 1995-1999; 
Number of bridges: 38,988. 

Year: 2000-2004; 
Number of bridges: 36,423. 

Year: 2005-2007; 
Number of bridges: 11,144. 

Source: GAO analysis of FHWA data. 

[End of figure] 

Figure 12: Deck Area of Bridges, by Year Built, 2007 (in million square 
feet): 

[See PDF for image] 

This figure is a vertical bar graph depicting the following data: 

Year: Before 1900; 
Deck area: 7,586,651. 

Year: 1900-1904; 
Deck area: 11,278,900. 

Year: 1905-1909; 
Deck area: 9,571,840. 

Year: 1910-1914; 
Deck area: 11,326,200. 

Year: 1915-1919; 
Deck area: 10,267,600. 

Year: 1920-1924; 
Deck area: 21,202,200. 

Year: 1925-1929; 
Deck area: 45,157,400. 

Year: 1930-1934; 
Deck area: 72,906,200. 

Year: 1935-1939; 
Deck area: 85,327,000. 

Year: 1940-1944; 
Deck area: 47,835,700. 

Year: 1945-1949; 
Deck area: 55,285,500. 

Year: 1950-1954; 
Deck area: 136,622,032. 

Year: 1955-1959; 
Deck areas: 259,926,032. 

Year: 1960-1964; 
Deck area: 368,536,064. 

Year: 1965-1969; 
Deck area: 396,067,072. 

Year: 1970-1974; 
Deck area: 391,341,056. 

Year: 1975-1979; 
Deck area: 281,056,064. 

Year: 1980-1984; 
Deck area: 241,878,032. 

Year: 1985-1989; 
Deck area: 271,794,048. 

Year: 1990-1994; 
Deck area: 286,868,064. 

Year: 1995-1999; 
Deck area: 271,824,064. 

Year: 2000-2004; 
Deck area: 270,24,064. 

Year: 2005-2007; 
Deck area: 96,263,320. 

Source: GAO analysis of FHWA data. 

[End of figure] 

Bridges have life spans that are dependent on factors such as 
materials, environment, level of use, and level of maintenance. One 
measure of condition is the sufficiency rating, which declines on 
average over time as a bridge ages (see fig. 13). As noted earlier in 
this report, (1) when a bridge has a sufficiency rating of 80 and below 
and is determined to be structurally deficient or functionally 
obsolete, it is eligible for HBP funds for rehabilitation and (2) when 
a bridge has a sufficiency rating below 50, and is determined to be 
structurally deficient or functionally obsolete, it is eligible for HBP 
funds for rehabilitation or replacement. Based on data for the bridges 
in the NBI, an average bridge would have a sufficiency rating low 
enough to make it eligible for rehabilitation when it is 39 years old 
and for replacement when it is 53 years old. 

Figure 13: Range of Sufficiency Ratings, by Bridge Age, 2007: 

[See PDF for image] 

This figure is a line graph depicting the following data: 

Average bridge age (in years): 0-10; 
Sufficiency rating range: 61.2. 

Average bridge age (in years): 11-20; 
Sufficiency rating range: 63.2. 

Average bridge age (in years): 21-30; 
Sufficiency rating range: 60.7. 

Average bridge age (in years): 31-40; 
Sufficiency rating range: 54.7. 

Average bridge age (in years): 41-50; 
Sufficiency rating range: 53.2. 

Average bridge age (in years): 51-60; 
Sufficiency rating range: 50.2. 

Average bridge age (in years): 61-70; 
Sufficiency rating range: 46.2. 

Average bridge age (in years): 71-80; 
Sufficiency rating range: 39.4. 

Average bridge age (in years): 81-90; 
Sufficiency rating range: 32.9. 

Average bridge age (in years): 91-100; 
Sufficiency rating range: 24.5. 

Source: GAO analysis of FHWA data. 

Note: Bridge age is based on the year the bridge was built or the year 
the bridge was reconstructed, whichever occurred later. One percent of 
the total number of bridges is not included due to missing or 
incorrectly coded data. 

[End of figure] 

As shown in figure 14, the number of deficient bridges is greatest for 
those built from 1950 through 1974, during which years the number of 
bridges and deck area of bridges built in the United States peaked. 
These bridges are now from 34 to 58 years old. The combination of an 
increased number and size of bridges built after 1949 that are now 
deficient and sufficiency ratings that decrease as bridges get older 
indicates that bridge conditions will likely begin to deteriorate 
resulting in more deficient bridges. The increase in the number and 
size of bridges built in 1950 and after will likely place a greater 
demand on the HBP for bridge rehabilitation and replacement than 
bridges built before 1950. 

Figure 14: Bridge Deficiency Status, by Year Built or Reconstructed, 
2007: 

[See PDF for image] 

This figure is a stacked vertical bar graph depicting the following 
data: 

Year: Before 1900; 
Bridges not deficient: 86; 
Bridges functionally obsolete: 443; 
Bridges structurally deficient: 192. 

Year: 1900-1904; 
Bridges not deficient: 1,172; 
Bridges functionally obsolete: 1,844; 
Bridges structurally deficient: 632. 

Year: 1905-1909; 
Bridges not deficient: 216; 
Bridges functionally obsolete: 750; 
Bridges structurally deficient: 219. 

Year: 1910-1914; 
Bridges not deficient: 397; 
Bridges functionally obsolete: 1,548; 
Bridges structurally deficient: 495. 

Year: 1915-1919; 
Bridges not deficient: 606; 
Bridges functionally obsolete: 1,373; 
Bridges structurally deficient: 645. 

Year: 1920-1924; 
Bridges not deficient: 1,520; 
Bridges functionally obsolete: 2,513; 
Bridges structurally deficient: 1,485. 

Year: 1925-1929; 
Bridges not deficient: 3,037; 
Bridges functionally obsolete: 2,763; 
Bridges structurally deficient: 2,106. 

Year: 1930-1934; 
Bridges not deficient: 7,147; 
Bridges functionally obsolete: 4,894; 
Bridges structurally deficient: 3,526. 

Year: 1935-1939; 
Bridges not deficient: 9,446; 
Bridges functionally obsolete: 6,143; 
Bridges structurally deficient: 3,906. 

Year: 1940-1944; 
Bridges not deficient: 6,249; 
Bridges functionally obsolete: 3,913; 
Bridges structurally deficient: 2,388. 

Year: 1945-1949; 
Bridges not deficient: 6,732; 
Bridges functionally obsolete: 2,750; 
Bridges structurally deficient: 2,518. 

Year: 1950-1954; 
Bridges not deficient: 14,940; 
Bridges functionally obsolete: 6,064; 
Bridges structurally deficient: 5,511. 

Year: 1955-1959; 
Bridges not deficient: 23,043; 
Bridges functionally obsolete: 6,242; 
Bridges structurally deficient: 7,128. 

Year: 1960-1964; 
Bridges not deficient: 32,200; 
Bridges functionally obsolete: 7,185; 
Bridges structurally deficient: 9,077. 

Year: 1965-1969; 
Bridges not deficient: 36,740; 
Bridges functionally obsolete: 6,096; 
Bridges structurally deficient: 8,000. 

Year: 1970-1974; 
Bridges not deficient: 37,366; 
Bridges functionally obsolete: 5,386; 
Bridges structurally deficient: 5,684. 

Year: 1975-1979; 
Bridges not deficient: 35,703; 
Bridges functionally obsolete: 3,888; 
Bridges structurally deficient: 4,694. 

Year: 1980-1984; 
Bridges not deficient: 37,596
Bridges functionally obsolete: 3,083
Bridges structurally deficient: 4,947 

Year: 1985-1989; 
Bridges not deficient: 44,543; 
Bridges functionally obsolete: 2,683; 
Bridges structurally deficient: 6,447. 

Year: 1990-1994; 
Bridges not deficient: 45,223; 
Bridges functionally obsolete: 2,060; 
Bridges structurally deficient: 6,548. 

Year: 1995-1999; 
Bridges not deficient: 44,635; 
Bridges functionally obsolete: 805; 
Bridges structurally deficient: 3,520. 

Year: 2000-2004; 
Bridges not deficient: 45,209; 
Bridges functionally obsolete: [Empty]; 
Bridges structurally deficient: [Empty]. 

Year: 2005-2007; 
Bridges not deficient: 13,308. 
Bridges functionally obsolete: [Empty]; 
Bridges structurally deficient: [Empty]. 

Note: Bridges are categorized by the year they were built or last 
reconstructed, whichever came later. Bridges fewer than 10 years old or 
fewer than 10 years since reconstruction are not allowed to be 
classified as structurally deficient or functionally obsolete, so no 
deficient bridge data appear for bridges after 1997. 

[End of figure] 

[End of section] 

Appendix III: GAO Contact and Staff Acknowledgments: 

GAO Contact: 

Katherine Siggerud, (202) 512-2834 or siggerudk@gao.gov: 

Staff Acknowledgments: 

In addition to the contact named above, JayEtta Hecker, Director; Rita 
Grieco, Assistant Director; Claudia Becker; Brian Chung; Carol Henn; 
Bert Japikse; Delwen Jones; Mitchell Karpman; Leslie Locke; Heather 
MacLeod; Sara Ann Moessbauer; Joshua Ormond; Max Sawicky; and Stan 
Stenersen made key contributions to this report. 

[End of section] 

Footnotes: 

[1] The House of Representatives passed H.R. 3999, the National Highway 
Bridge Reconstruction and Inspection Act of 2008, on July 24, 2008, and 
a Senate companion bill, S. 3338, was introduced in the Senate 
Committee on Environment and Public Works on July 25, 2008. Besides 
adding $1 billion in funds to what was authorized for 2009 for HBP and 
other related programs in the most recent surface transportation 
authorizing legislation enacted in 2005, the legislation requires the 
Department of Transportation to strengthen bridge inspection standards, 
adopt a risk-based process for prioritizing certain bridge 
rehabilitation and replacement projects, ensure that states develop 
performance plans, and take other actions. We discuss the implications 
of our work on the HBP for related provisions of this proposed 
legislation in a testimony delivered at a hearing today before the 
Senate Committee on Environment and Public Works. See GAO, Highway 
Bridge Program: Clearer Goals and Performance Measures Needed for a 
More Focused and Sustainable Program, [hyperlink, 
http://www.gao.gov/cgi-bin/getrpt?GAO-08-1127T] (Washington, D.C.: 
Sept. 10, 2008). 

[2] See GAO, 21st Century Challenges: Reexamining the Base of the 
Federal Government, [hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-
05-325SP] (Washington, D.C.: Feb. 1, 2005) and GAO, High Risk Series: 
An Update,[hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-07-310] 
(Washington, D.C.: Jan. 31, 2007). 

[3] GAO, Surface Transportation: Restructured Federal Approach Needed 
for More Focused, Performance-Based, and Sustainable Programs, 
[hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-08-400] (Washington, 
D.C.: Mar. 6, 2008). 

[4] 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. 

[5] The National Transportation Safety Board has an investigation under 
way to determine the cause of the I-35W bridge collapse. DOT's Office 
of Inspector General has a study under way to evaluate the National 
Bridge Inspection Program. 

[6] Routine bridge inspections are generally conducted every 24 months, 
but with FHWA approval, the inspection interval may be extended to 48 
months on certain bridges. 

[7] A sufficiency rating is a score from 0 to 100 assigned to each 
bridge, reflecting its structural adequacy, safety, serviceability, and 
essentiality for public use. A rating of 100 represents an entirely 
sufficient bridge, and 0 represents an entirely insufficient bridge. 

[8] 23 U.S.C. § 144(f) guarantees each state a minimum of 0.25 percent 
or a maximum of 10 percent of the total annual HBP apportionment. 

[9] State funds from other Federal-aid highway programs such as the 
Interstate Maintenance Program and Surface Transportation Program have 
also been 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. 

[10] See 23 U.S.C. § 144. 

[11] A bridge management system is a system of formal procedures and 
methods for gathering and analyzing bridge data to predict future 
bridge conditions, estimate maintenance and improvement needs, 
determine optimal policies, and recommend projects and schedules within 
budget and policy constraints. 

[12] The HBP was preceded by two other federal programs that assisted 
states in funding bridges. The first federal bridge program was the 
Special Bridge Replacement Program, which Congress established in 1970 
to provide federal funding to states to support replacement of unsafe 
bridges on the Federal-aid highway system. In 1978, this program was 
replaced by the Highway Bridge Replacement and Rehabilitation Program 
(HBRRP), which expanded the federal funding role to assist states in 
rehabilitating and replacing deficient bridges, both on and off the 
Federal-aid highway system. The HBRRP has been further expanded through 
subsequent legislation and is currently known as the HBP. 

[13] The 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. Just as HBP funds may be transferred to these other Federal- 
aid highway programs, funds from these programs may also be spent on 
bridges. 

[14] The federal share for bridge projects on the interstate system is 
90 percent. 

[15] The 52 FHWA division offices are located in each state, the 
District of Columbia, and Puerto Rico. 

[16] The 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. 

[17] The 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. 

[18] States are generally required to spend at least 15 percent of 
their HBP funds on non-Federal-aid highway bridges. 

[19] States may also use HBP funds on otherwise ineligible bridges for 
seismic retrofitting projects, systematic preventive maintenance, and 
installation of scour countermeasures. 

[20] Bridge condition ratings form the basis for assessing the 
structural condition of a bridge. Condition ratings use a rating 
system, where 9 indicates excellent, as-new condition, and 0 indicates 
a failed condition. Codes 7 through 9 indicate good to excellent 
conditions. Codes 5 and 6 indicate either fair or satisfactory 
conditions of the components. Codes 0 through 4 indicate failed 
conditions, conditions representing imminent failure of the component, 
critical conditions, serious, or poor conditions. 

[21] DOT, 2006 Status of the Nation's Highways, Bridges, and Transit: 
Conditions and Performance (Washington, D.C., Jan. 22, 2007). 

[22] The superstructure is the portion of a bridge structure that spans 
the obstacle the bridge is intended to cross. The substructure consists 
of all parts that support the superstructure. 

[23] The cause of the I-35W bridge collapse has not yet been 
determined; National Transportation Safety Board expects to release the 
results of its investigation by December 2008. Although the National 
Transportation Safety Board's investigation is ongoing and no 
determination of probable cause has been reached, investigators have 
raised concerns about certain elements of the bridge (gusset plates) 
and issued a safety recommendation to FHWA that bridge owners conduct 
load capacity calculations to verify that the stress levels in all 
structural elements, including gusset plates, remain within applicable 
requirements. 

[24] DOT, 2006 Status of the Nation's Highways, Bridges, and Transit: 
Conditions and Performance. 

[25] HBP also provides funds for bridge set-asides (or designated 
projects), historic bridges, and other projects. 

[26] The three exceptions include the following: (1) SAFETEA-LU 
requires that $100 million for fiscal year 2005 be set aside for bridge 
projects at the U.S. Department of Transportation Secretary's 
discretion; (2) SAFETEA-LU requires that $100 million for each of 
fiscal years 2006 through 2009 be set aside for nine bridge projects 
designated in SAFETEA-LU, see 23 U.S.C. § 144(g)(1); and (3) 1.25 
percent of authorized program funds are set aside for metropolitan 
planning, see 23 U.S.C. § 104(f)(1). 

[27] 23 U.S.C. § 144(e). 

[28] The 3-year average of each state's bridge construction unit costs 
is used as that state's replacement cost. The rehabilitation cost is 
then calculated as 68 percent of that state's bridge replacement cost. 

[29] 23 U.S.C. § 144(e). In fiscal year 2006, three states (North 
Dakota, Nevada, and Wyoming) received the minimum apportionment amount, 
and one state (New York) received the maximum amount of HBP funds 
allowable. 

[30] Since SAFETEA-LU, the Equity Bonus Program has provided funding to 
states based upon equity considerations. The Equity Bonus Program 
guarantees that each state will receive (1) at least a statutorily 
specified percentage (referred to as the "relative rate of return") of 
its estimated contribution to the Highway Account of the Highway Trust 
Fund and (2) a minimum percentage of funding in excess of the average 
annual program apportionments the state received under prior 
authorizations. 

[31] SAFETEA-LU eliminated the 35 percent cap on non-Federal-aid bridge 
expenditures. 

[32] See 23 U.S.C. §144(g)(2)(B). 

[33] TxDOT's precise goal is to make 80 percent of Texas bridges in 
"good or better" condition by September 2011. To be classified in good 
or better condition, a bridge is not structurally deficient, 
functionally obsolete, or substandard for load only. A bridge is 
considered substandard for load only if it is not structurally 
deficient or functionally obsolete but has a load capacity less than 
the maximum load capacity permitted by state law. 

[34] GAO has a study under way examining other federal mobility 
programs designed to meet national and regional transportation 
priorities, which also include some large highway bridge projects. 

[35] Missouri has a total of 24,017 bridges, 43 percent of which are 
state-owned. 

[36] There 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. 

[37] According to MoDOT officials, Missouri has around 203 "major" 
bridges, 53 of which cross the Mississippi and Missouri Rivers. Major 
bridges comprise around 25 percent of Missouri's total bridge deck 
area. 

[38] Bridges are coded in the NBI by either a rural or urban 
classification. A bridge is coded as rural if it is not located inside 
a designated urban area. 

[39] Approximately 75 percent of the nation's bridges are rural, and 25 
percent are urban. 

[40] GAO, Federal-Aid Highways: Trends, Effect on State Spending, and 
Options For Future Program Design, [hyperlink, http://www.gao.gov/cgi-
bin/getrpt?GAO-04-802] (Washington, D.C.: Aug. 31, 2004). 

[41] The age of a bridge is based on the number of years since it was 
built or reconstructed. 

[42] GAO, Physical Infrastructure: Challenges and Investment Options 
for the Nation's Infrastructure, [hyperlink, http://www.gao.gov/cgi-
bin/getrpt?GAO-08-763T] (Washington, D.C.: May 8, 2008). 

[43] [hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-05-325SP]. 

[44] [hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-08-400]. 

[45] Also see GAO, Surface Transportation Programs: Proposals Highlight 
Key Issues and Challenges in Restructuring the Programs, [hyperlink, 
http://www.gao.gov/cgi-bin/getrpt?GAO-08-843R] (Washington, D.C.: July 
29, 2008). 

[46] [hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-08-400]. 

[47] [hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-08-400]. 

[48] GAO, Surface Transportation: Strategies Are Available for Making 
Existing Road Infrastructure Perform Better, [hyperlink, 
http://www.gao.gov/cgi-bin/getrpt?GAO-07-920] (Washington, D.C.: July 
26, 2007). 

[49] See GAO, Highway Finance: States' Expanding Use of Tolling 
Illustrates Diverse Challenges and Strategies, [hyperlink, 
http://www.gao.gov/cgi-bin/getrpt?GAO-06-554] (Washington, D.C.: June 
28, 2006). 

[50] DOT, Refocus, Reform, Renew: A New Transportation Approach for 
America (Washington, D.C.: July 29, 2008). 

[51] See [hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-08-400]. 

[52] The NHS consists of approximately 160,000 miles of roadway 
important to the nation's economy, defense, and mobility. It includes 
interstate highways and other principal arterials in rural and urban 
areas, the Strategic Highway Network that provides defense-related 
access, and intermodal connectors. 

[54] Bridge deck area data in this appendix does not include bridges 
classified as culverts where no deck width is required to be recorded 
in the NBI and a deck area can not be calculated. 

[End of section] 

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