Highway Bridge Program: Clearer Goals and Performance Measures Needed for a More Focused and Sustainable Program
Released: 2008-09-10T00:00:00

Letter

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. 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 federal standards, known as the National Bridge Inspection Standards, and program requirements for the proper safety inspection and evaluation of bridges. These standards establish by whom, with what frequency, and how bridge inspections are to be completed. For example, state departments of transportation (DOTs) carry out the federal- level policies, procedures, and requirements for inventory, inspection, bridge load ratings, quality assurance, and reports. 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 conditions, during the inspection and report that information to the NBI, maintained by FHWA headquarters.

Based on information gathered during bridge inspections and reported to the NBI, the HBP classifies bridge conditions as deficient or not; assigns each bridge a sufficiency rating reflecting its structural adequacy, safety, serviceability, and relative importance; and uses that information to provide funding for states to improve bridges. Deficient bridges include those that are structurally deficient, with one or more components in poor condition, and those that are functionally obsolete, with a poor configuration or design that may no longer be adequate for the traffic they serve. FHWA uses information in the NBI to annually apportion HBP funds to the states. While each state’s HBP apportionment amount is largely determined by bridge conditions and bridges generally must be below a certain condition threshold to qualify for HBP funding, other bridges are also eligible for HBP funds because states may use the funds for a broad array of other purposes, such as bridge preventive maintenance projects.

All bridges are grouped into one of two general categories: Federal-aid highway bridges and bridges not on Federal-aid highways. The NBIP and the HBP generally apply to both categories of bridges located on public roads. Federal-aid highway bridges are generally located on the National Highway System, a 160,000–mile network that carries over 40 percent of the nation’s highway traffic. Non-Federal-aid highway bridges are generally located on local or rural roads that carry lower volumes of traffic than state-owned bridges.

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. The HBP gives states three key flexibilities in determining how to use their HBP resources. First, the HBP has evolved to allow states to use program funds not only for bridge replacement and rehabilitation, but also for a broad array of purposes—including painting, seismic retrofitting, systematic preventive maintenance, installation of scour countermeasures (to address the effects of sediment erosion around bridge piers and abutments), and anti-icing or deicing applications— regardless of the bridge’s condition. In addition, FHWA has determined that the costs for personnel and equipment used in bridge inspections and for bridge management systems are consistent with the purpose of the HBP and therefore are also eligible uses for HBP funds. Thus, states have the flexibility to use HBP funds on bridge projects that may not immediately reduce their inventory of deficient bridges. Secondly, states have flexibility in determining how to split HBP resources between state and locally owned bridges. Aside from a requirement to distribute funds equitably, the only HBP requirement applicable to states’ allocation of program funds is that states must spend a minimum (15 percent) on non- Federal-aid highway bridges. Third, states may also spend program funds on other, nonbridge, transportation priorities by transferring up to 50 percent of their annual HBP funding to other core Federal-aid highway programs, though a penalty is invoked by reducing the state’s HBP funds in the succeeding year by the amount transferred. Many states have taken advantage of this provision over the years and transferred some of their HBP funding to other programs, although FHWA officials pointed out that some of the transferred HBP funds may still be spent on bridges and funds from other Federal-aid highway programs may also be spent on bridges. FHWA data show that significant funds have flowed toward bridges from other programs which, from a national perspective, exceed outflows from the HBP. Finally, planning for how HBP funds are spent is generally under the control of state DOTs; once states select bridge projects, they may apply to FHWA for the federal share of the costs, which is generally 80 percent of the project cost.

In part due to these flexibilities, state DOTs we visited have established a range of priorities for their HBP funds—from reducing the number of their deficient bridges to seismically retrofitting their bridges—and some opted to transfer their HBP funds to fund other transportation priorities. Although the key purpose of the HBP is to enable states to improve the condition of their deficient bridges, some state transportation officials we interviewed explained that they do not focus on reducing their inventories of deficient bridges for several reasons: Deficient bridges are not necessarily unsafe. Many state transportation officials we interviewed told us that some of the deficient bridges in their states are in at least reasonably good condition and are safe. In addition, FHWA reported in 2007 that classifying a bridge as deficient does not immediately imply that it is likely to collapse or that it is unsafe. According to the FHWA report, if proper vehicle weight restrictions are posted and enforced, deficient bridges can continue to serve most traffic conditions. FHWA requires that bridge owners close to traffic any bridges that they determine to be unsafe.

The HBP apportionment formula may create a disincentive to improve deficient bridges. Many federal and state officials we met with noted this potential disincentive that occurs because reducing the number and deck area of deficient bridges reduces a state’s HBP funding eligibility.

Some deficient bridge projects can be cost-prohibitive. Some state officials explained that certain large-scale bridge projects—often the most traveled, urban bridges on interstate corridors—are too expensive to be implemented with HBP funds alone, especially costly “mega” projects that have an estimated total cost greater than $500 million.

State DOTs use a variety of criteria, tools, and methods to select among potential bridge projects. Officials in the six states we visited use criteria such as bridge condition ratings, average daily traffic over bridges, local transportation priorities, or funding availability when prioritizing and selecting among potential bridge projects. Some states have also developed tools and approaches beyond those required by the HBP—such as bridge management systems, element-level inspections, state-specific condition ratings, and various prioritization approaches—to help them gauge bridge conditions and further inform their selection of bridge projects for funding. For example, all of the states we visited have adopted, or are considering, some form of bridge management system for gathering and analyzing bridge data to help manage their bridge assets and more efficiently allocate limited HBP resources among competing bridge priorities. States use these systems to predict future bridge conditions, estimate bridge maintenance and improvement needs, determine optimal policies for rehabilitation and replacement, and recommend projects and schedules within budget and policy constraints. FHWA has actively encouraged, but has not required, states to use bridge management systems, in part, by providing state transportation officials with relevant training and technical support. In addition, all of the states we visited required bridge inspectors to gather more detailed “element-level” bridge condition data, thereby exceeding the federal inspection requirements that require inspection of only the three major bridge components (superstructure, substructure, and deck). Furthermore, some state DOTs use their own bridge rating systems to better gauge bridge conditions and to inform their selection of bridge projects for funding. For example, the New York State DOT uses its own condition rating scale, which is based on an assessment of 47 individual bridge elements, to prioritize bridge projects. Finally, state DOTs use different methods to prioritize and select bridge projects for funding. Whereas some states we visited had highly centralized prioritization processes, others allowed the process to vary across the state.

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

Bridge conditions, as measured by the number of deficient bridges and average sufficiency rating, improved from 1998 through 2007. According to NBI data, the total number of deficient bridges—including both structurally deficient and functionally obsolete bridges—has decreased over the last 10 years, even as the total number of bridges has increased. From 1998 through 2007, the number of deficient bridges declined by nearly 12 percent, from 172,683 to 152,317, even with the addition of more than 16,000 new bridges to the NBI (see fig. 1).

The decline in the overall number of deficient bridges over the past decade reflects a reduction in the number of structurally deficient bridges. From 1998 through 2007, the number of structurally deficient bridges decreased by 22 percent, from 93,118 to 72,519 (see fig. 2). During that same period, the number of functionally obsolete bridges increased slightly from 79,565 to 79,798, an increase of 233 bridges. The reduction in the number of structurally deficient bridges, rather than functionally obsolete bridges, over this time period may reflect bridge owners’ efforts to address the deterioration or damage that are characteristic of structurally deficient bridges. Although reducing or eliminating structurally deficient bridges may not always be a state’s highest priority, structurally deficient bridges often require maintenance and repair to remain in service. By contrast, functionally obsolete bridges do not necessarily require repair to remain in service and, therefore, are unlikely to be transportation officials’ top priority for rehabilitation or replacement.

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.

Improvements were most notable in bridges owned by local agencies and on rural routes, which may be attributable, in part, to the federal bridge program requirement—under HBP and some of its predecessor programs—that states spend a minimum amount of their apportionment 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. 3).

With respect to urban and rural bridges, the number of deficient rural bridges declined from 1998 through 2007 and the number of deficient urban bridges increased. From 1998 through 2007, the number of deficient rural bridges decreased by about 19 percent, from 130,910 to 106,209. During that same period, the number of deficient urban bridges increased by about 11 percent, from 41,659 to 46,086 (see fig. 4). The average sufficiency rating for both rural and urban bridges improved slightly from 1998 through 2007; for rural bridges, the average rating increased from 74 to 78, and for urban bridges, the average rating increased from 79 to 82.

A bridge is classified as rural in the NBI database if it is not located inside a designated urban area. state and local bridge spending, the expansion of bridge project eligibility, and limitations in the NBI data. First, the impact of the federal investment in the HBP is difficult to measure in part because there are no comprehensive data for state and local spending on bridges. FHWA does track a portion of each state’s capital spending on bridges, and the agency has generated a single, national level estimate for total bridge expenditures by all government levels; however, there are significant gaps in this information, and neither source is comprehensive or detailed enough to be used to determine the impact of the HBP. The state transportation officials we spoke with during our site visits estimated that state and local spending on bridges ranged from the minimum match amount (generally 20 percent of the HBP apportionment amount) to more than four times the state’s apportioned HBP funds. Our previous work has shown that although federal investment in HBP and other Federal-aid highway programs has increased over time, this investment has not resulted in commensurate increases in the nation’s total government spending (federal, state, and local) on its highway system. In particular, as the level of federal funding has increased since the mid-1990s, states have not maintained their level of effort in highway spending, and federal funds have increasingly been substituted for state funds. This suggests that increased federal highway funding influences states and localities to substitute federal funds for state and local funds they otherwise would have spent on highways and bridges.

Second, the impact of the HBP is also difficult to measure because HBP funds can, in some cases, be used for a variety of bridge projects without regard to a bridge’s deficiency status or sufficiency rating. Therefore, simply measuring changes in the number of structurally deficient or functionally obsolete bridges does not reflect the full impact of the program since these measures do not capture the impact of the HBP investment in the other eligible activities that do not necessarily result in an immediate reduction in the number of deficient bridges. Without quantifiable performance measures to track the full range of desired outcomes for the HBP, it is difficult to measure the program’s impact and determine the extent to which the program is serving its stated purpose.

Finally, another difficulty in determining the impact of HBP funding occurs because the NBI does not readily permit changes in the condition of a group of bridges to be tracked across time. Each bridge in the NBI is assigned an identifying number by the relevant state DOT. However, the identifying number for a bridge at a specific location may change over the life of that bridge. Such a change may occur when a state renumbers, replaces, or closes and subsequently reopens a bridge. As a result, it is difficult to track changes in the condition of any specific bridge or group of bridges to determine if, for example, the same bridges that were deficient in 1998 are still deficient today, to see how many bridges have been replaced, or to determine the impact of new bridges added to the inventory (which may not be funded by the HBP) on the overall condition of the nation’s bridges.

Evaluating the impact of the HBP is important not only to understand the outcomes of past spending but also to determine how to sensibly invest future federal resources. The number of HBP-eligible bridges is expected to increase as a large share of the nation’s bridges built in the 1960s and early 1970s age and become eligible for rehabilitation and replacement as a group; as a result, states and local agencies may see a spike in their need for bridge rehabilitation and replacement funding. In this environment of increasing demand for limited resources, it is especially important for FHWA and Congress to be able to evaluate the impact of the HBP in order to ensure that the program is providing an acceptable return on investment and addressing national transportation priorities.

The HBP Lacks Focus, Performance Measures, and Sustainability

The HBP, while generally helping to improve bridge conditions, does not fully align with our principles for re-examining surface transportation programs in that the bridge program lacks focus, performance measures, and sustainability. Our principles, which are based on our prior work and federal laws and regulations, include: (1) ensuring program goals are well defined and focused on the federal or national interest, (2) incorporating performance and accountability into funding decisions, (3) employing the best tools and approaches to emphasize return on targeted federal investment, and (4) ensuring fiscal sustainability.

First, HBP’s goals are not focused on a clearly identified federal interest. Over the years, the program’s statutory goals have expanded from improving deficient bridges to supporting seismic retrofitting, preventive maintenance, and many other activities, thus expanding the federal interest to potentially include almost any bridge in the country. Our previous work has emphasized the importance of identifying clear areas of federal interest as a first step in determining program goals. For example, if mobility is determined to be a key federal interest and a primary goal, the HBP could be targeted toward bridges whose conditions have the most impact on congestion and economic competitiveness and that carry higher levels of traffic or freight than those bridges in remote areas that may serve only a few people each day. If rehabilitating and reducing deficient bridges is determined to be a key federal interest, then the program could be further targeted toward that goal. The federal interest may also be greater in bridge projects that are too expensive for states to undertake without additional federal assistance or in projects that extend beyond the borders of a single state. Once the federal interest has been determined, our principles call for basing the federal share of the cost of bridge projects on the level of federal interest.

Second, there is no clear tie between HBP funding and performance. HBP funds are apportioned to states without regard to program performance because the HBP formula is based on a calculation of needed repairs to deficient bridges but does not consider a state’s efforts or effectiveness in reducing its inventory of deficient bridges or controlling costs. Because the formula does not factor in other eligible program activities, such as systematic preventive maintenance, there is no link between the apportionment formula and the states’ performance of these activities. Without performance measures to link funding to performance, states lack an incentive to improve the return on the federal investment and are not held accountable for the results of their investments. Our work has shown that an increased focus on performance and accountability for results can help the federal government better target limited federal resources.

Third, the HBP generally lacks sufficient tools to determine the effects of the federal investment in bridges. In this regard, bridge management systems, which are currently used by many states but not required by the program’s authorizing legislation, may be useful for prioritizing projects and making funding decisions to improve results and emphasize return on investment.

Finally, the HBP’s fiscal sustainability remains a challenge in light of aging bridge infrastructure, coupled with the declining purchasing power of funding currently available for bridge maintenance, rehabilitation, replacement and the recent growth in construction costs. Based on our prior work, two tools that could possibly improve the sustainability of the HBP are a maintenance-of-effort requirement and tolling. A maintenance- of-effort requirement, whereby state or local grantees would be required to maintain their own level of funding in order to receive HBP funds, could reduce the potential substitution of federal funds for state and local funds under the program. In addition, our prior work has shown that removing barriers to, or even promoting, tolling can lead to more efficient management of existing infrastructure and capacity. Addressing the HBP’s future fiscal sustainability is critical, given the overall fiscal imbalance facing the nation and the lack of assurance that HBP funding is allocated to projects that are in the federal interest and provide the best return on investment.

Observations on Proposed Bridge Legislation

Our work on the HBP can provide some perspective on several provisions in the proposed legislation under review by this committee, the National Highway Bridge Reconstruction and Inspection Act of 2008 (S. 3338). The legislation proposes, among other things, to authorize an additional $1 billion for fiscal year 2009 from the U.S. Treasury’s general fund to address bridge infrastructure. The legislation would also require DOT to strengthen bridge inspection standards, adopt a risk-based process for prioritizing certain bridge rehabilitation and replacement projects, and require that states develop 5-year performance plans for bridge inspections and for the rehabilitation or replacement of deficient bridges.

As summarized below, our work on the HBP is related to several provisions in the proposal: For example, the legislation calls for DOT to apply a risk-based prioritization process to every structurally deficient or functionally obsolete bridge in the nation. While such a process could potentially help target scarce federal resources to bridges that are most critical to safety and mobility, many state transportation officials we interviewed during our work raised questions about the appropriateness of focusing on all deficient bridges, noting that all deficient bridges are not necessarily unsafe and some large-scale deficient bridge projects can be too cost- prohibitive to be implemented with HBP funds alone. Also, the legislation is unclear about how, if at all, the new risk-based prioritization process will differ from or relate to DOT’s established sufficiency rating process. FHWA uses sufficiency ratings primarily to determine HBP eligibility and apportion funds. We found that states may consider sufficiency ratings in their prioritization processes but generally do not rely on these to prioritize bridge projects.

In addition, the legislation calls for DOT to require states to develop 5-year performance plans covering the inspection and rehabilitation or replacement of all structurally deficient or functionally obsolete bridges. We support the use of performance plans to articulate program goals that are in the federal interest, encourage accountability for results, and help ensure that the federal government targets resources to programs that best achieve intended outcomes and national priorities. Our work has shown that the current HBP funding formula is not linked to a state’s performance in reducing its inventories of deficient bridges and we are recommending in our report being issued today that DOT work with Congress to define specific national goals and performance measures for the HBP. This legislative provision might be strengthened by requiring states to report on their progress in achieving their goals as part of each annual update to their performance plan. Also, the legislation requires that the performance plans be focused on all deficient bridges, and the same issue that I raised earlier about the appropriateness of this focus applies here as well.

The legislation also calls for DOT to require the states to develop and implement a bridge management system. In our work on the HBP, all six states we visited had adopted, or were considering, some form of bridge management system to help manage their bridge assets and more efficiently allocate limited HBP resources among competing bridge priorities. In the report we are releasing today, we are recommending that DOT evaluate and incorporate into the HBP best tools and practices, such as bridge management systems.

Conclusions and Recommendations

Although many aspects of the HBP are carried out at the state level—with ultimate responsibility for bridge inspection and project selection residing with the states—the federal government bears responsibility for ensuring that the program achieves results that are in the federal interest and that the program’s resources are allocated efficiently. The purpose of the HBP has greatly expanded over the years, making nearly any bridge potentially eligible for federal funding, and as a result, the federal interest in bridges lacks focus. Additionally, many state officials told us that measures used by the HBP to apportion federal funds—bridge deficiency status and sufficiency ratings—are not necessarily good proxies for the safety or risk associated with specific bridges. Even though data indicate that the number of structurally deficient bridges has declined over the last 10 years, most of this improvement has been in locally owned and rural bridges. Oftentimes, the largest and most critical bridges carrying more interstate commerce are too expensive to be funded by the HBP and so require other funding sources to be replaced or rehabilitated. Moreover, without comprehensive data on state and local spending on bridges, it is impossible either to distinguish the impact of HBP funding from the impact of state and local bridge funding or to determine the extent to which states are substituting HBP funding for state and local funds that would otherwise have been spent on bridges. Absent clear goals and related performance measures for the HBP, it is difficult to determine the overall effectiveness of the program’s investment in bridges.

Our principles have suggested several ways to improve the HBP to ensure that it is more focused and performance-based in the future. For example, tools such as bridge management systems provide bridge managers with a more systematic approach to prioritizing projects and making funding decisions. Our work has shown that some states are using bridge management systems and other tools that generally exceed federal standards. Additionally, linking program goals to performance measures to determine whether goals are met and using that information to select projects and make funding decisions, can create incentives for state and local governments to improve the performance of their bridge programs, as well as the overall transportation system. As the projected revenue shortfall in the Highway Trust fund rapidly approaches and as bridge costs rise and infrastructure continues to age, incorporating strategies to better ensure the fiscal sustainability of the HBP is also critical.

To improve the focus, performance, and sustainability of the HBP, the report we are releasing at this hearing recommends that the Secretary of Transportation work with Congress to take the following actions: identify and define specific national goals for the HBP; determine the performance of the program by developing and implementing performance measures related to the goals for the HBP; identify and evaluate best tools and practices that can potentially be incorporated into the HBP, such as bridge management systems; and review and evaluate HBP funding mechanisms to align funding with performance and support a targeted and sustainable federal bridge program.

In reviewing a draft of the report, DOT officials said that they generally agreed with our findings and recommendations, and they provided technical comments which we incorporated in the report and this testimony, as appropriate. DOT officials also commented that they thought our re-examination principles had broader applicability than just the HBP—noting that DOT had incorporated our principles into the Department’s recent proposal for reforming surface transportation programs. DOT’s reform proposal, released in July 2008, recommends consolidating the existing network of over 100 surface transportation programs into eight broad, intermodal programs. 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.

Chairman Boxer, this concludes my prepared statement. I would be happy to respond to any questions that you or members of the committee may have.

GAO Contact and Staff Acknowledgments

For further information on this statement, please contact Katherine Siggerud at (202) 512-2834 or siggerudk@gao.gov. Individuals making key contributions to this testimony were Rita Grieco, Assistant Director; Claudia Becker; Stephanie Fain; Carol Henn; Bert Japikse; Delwen Jones; Leslie Locke; and Sara Ann Moessbauer.

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