About LTBP

This research was conducted 

as part of the Federal Highway 

Administration’s Long-Term 

Bridge Performance (LTBP) 

Program. The LTBP Program is 

a minimum 20-year research 

effort to collect scientific performance field data, from 

a representative sample of 

bridges nationwide, that will 

help the bridge community 

better understand bridge 

deterioration and performance. 

The products from this program will be a collection of 

data-driven tools including 

predictive and forecasting 

models that will enhance the 

abilities of bridge owners to 

optimize their management 

of bridges.

Objective

The objective of this TechBrief is to describe the bridge 

performance issues that will be studied under the LTBP 

Program, including how they were identified and prioritized 

with the assistance of bridge owners and other key 

stakeholders in the bridge community. It is intended for 

bridge owners and the bridge community at large (i.e., bridge 

engineers, bridge inspectors, and bridge asset managers) 

interested in the activities of the LTBP Program. 

Introduction

The performance of any single bridge or component of a 

bridge is dependent on multiple factors, many of which are 

closely linked. They include the original design parameters 

and specifications (bridge type, materials, geometries, load 

capacities); initial quality of materials and quality of the asbuilt construction; varying conditions of climate, air quality, 

and soil properties; and corrosion and other deterioration 

processes. Other factors influencing performance include 

traffic volumes, counts and weights of truck loads and truck 

live load impacts, and damage sustained as a result of scour, 

seismic events, wind, etc. A final critical factor influencing 

performance is the type, timing, and effectiveness of preventive maintenance, of minor and major rehabilitation actions, 

and ultimately of replacement actions applied to the bridge. 

FHWA Publications No.: FHWA-HRT-14-043

FHWA Contact: Susan Lane, HRDI-60, (202) 493-3151, susan.lane@dot.gov

This document is a technical summary of the published Federal Highway Administration (FHWA) 

report Long-Term Bridge Performance High Priority Bridge Performance Issues (FHWA-HRT-14-052), 

available through the National Technical Information Service at www.ntis.gov.

NTIS Accession No. of the report covered in this TechBrief: PB2014-106340

Research, Development, and Technology | Turner-Fairbank Highway Research Center | 6300 Georgetown Pike, McLean, VA 22101-2296

http://www.fhwa.dot.gov/research/

Long-Term Bridge Performance High 

Priority Bridge Performance Issues

TECHBRIEF
2

All of these factors combine to affect the condition and operational capacity of the bridge and 

its various structural components at any point 

in the life of the bridge. Currently, some important aspects of bridge performance are not well 

understood, and some of the main performance 

factors are not well documented because crucial 

data are not available or are difficult and costly 

to collect and analyze. 

The LTBP Program is designed in part to collect critical performance data that are not 

available elsewhere and merge them with 

data gathered from available sources. The 

overall objective of the LTBP Program is to 

inspect, evaluate, and periodically monitor 

representative samples of bridges nationwide 

to collect, document, maintain, and manage 

high-quality quantitative performance data 

over an extended period of time. Much of the 

data collected under the LTBP Program will 

be from inspection and testing of in-service 

bridges. Collection of high-quality quantitative 

performance data over an extended period of 

time will require resources and commitment 

on the part of bridge owners to provide access 

to their bridges and allow lane closures. These 

factors magnify the importance of selecting 

study topics that have great potential for payoff in terms of better, long-term bridge performance on a widespread scale. 

To assist with the challenge of selecting high 

priority topics for the LTBP Program, the 

possible performance issues were first classified into four broad categories. This is the 

starting point for beginning to identify the 

performance issues that are most important 

to owners. As figure 1 shows, the four primary issues in bridge performance are the 

following: 

• Structural condition—durability and 

serviceability (including fatigue).

• Functionality—user safety and service.

• Costs (to State transportation departments 

and users).

• Structural integrity—safety and stability in 

failure modes.

Figure 1. Categories of bridge performance issues.

Stakeholder Input—State 

Transportation Department 

Focus Groups

At an early stage in the development phase, 

three issues were identified for which input 

from bridge owners was important to the 

development and implementation of the LTBP 

Program. First was the need to determine what 

aspects of bridge performance were most 

important to the owners and then to determine what gaps existed in owners’ understanding of these aspects. That information is the 

focus of this TechBrief. Second was the 

need to examine what information data 

owners currently had for use in their 

decisionmaking processes and to identify 

where there were critical gaps in available 

data and knowledge. That information will 

be the focus of the upcoming FHWA 

TechBrief Identifying Long-Term Bridge 

Performance Data Needs. Third was to understand bridge owners’ decisionmaking 

processes and business practices to help 

identify what products the LTBP Program 

could develop that would best assist them 

in managing their bridge programs. That 

information was used internally by FHWA. 

The approach selected to collect this information was to hold a series of focus groups across 

a number of geographically distributed States. 

The best source of the required information was 

deemed to be the State transportation departments. Therefore, focus group meetings were 

designed to allow interviews with a group of 

bridge inspectors, engineers, and managers 
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from each of the selected States. As a result 

of the meetings, valuable information was 

obtained on performance issues of concern, 

data needs, performance measures that the 

departments of transportation currently use, 

and what those departments saw as desired 

outcomes of the program. 

To facilitate discussions, each group of State 

transportation department bridge personnel 

was asked to come to the meetings ready to 

discuss the following:

1. Organizational structure and processes 

within the department of transportation 

relative to bridge funding, design, 

management, inspection, and maintenance 

programming.

2. The 5 to 10 most common forms of deterioration, damage, or functional issues faced 

in maintaining, repairing, or rehabilitating 

highway bridges.

3. The 5 to 10 most common bridge maintenance, repair, or rehabilitation activities 

on which the department of transportation 

expends the most resources, with estimates 

of man-hours and funds spent on each 

annually. 

Figure 2 shows the States where focus group 

meetings were held in 2008 and 2009.

Figure 2. Participating State transportation departments.

Participating State transpor ticipating State transportation depa tation departments
4

Other Stakeholder Solicitation

During the development phase of the LTBP 

Program and even prior to its start, FHWA 

and the research team sought input on 

critical aspects of bridge performance from 

key stakeholders and strived to maintain 

a continuing dialogue with members of the 

bridge community. An important element 

of that dialogue was the discussion of the 

bridge performance issues that the program could and should study. This dialogue 

was carried on in workshops and technical 

conference sessions devoted to LTBP, in 

briefings and discussions with bridge-related 

technical committees from the American 

Association of State Highway and Transportation Officials (AASHTO) and the Transportation Research Board (TRB), and in informal 

meetings with State transportation department 

bridge personnel. 

In January 2007, FHWA, the National Science 

Foundation, and the University of Nevada—

Reno cosponsored a workshop in Las Vegas 

to develop initial strategies and recommendations for implementing the LTBP Program. 

The workshop was attended by 46 professionals from State transportation departments, 

FHWA, industry, and academia. The purpose 

of the workshop was to gather the collective 

advice of these experts on how to implement 

the program and, most important, what they 

would suggest for the priorities for collection 

of bridge data. The workshop did not produce 

recommendations on performance issues 

to study but did generate a comprehensive 

list of data that could be collected on the 

priorities and conditions of bridge elements 

and materials. See the upcoming report 

Identifying Long-Term Bridge Performance 

Data Needs to learn more about the data 

identified. However, the lists of data 

recommended for collection clearly indicate 

an emphasis on the condition of the major 

elements of the bridge as a focal point of key 

bridge performance issues. 

Based on the input received at the focus group 

meetings, several issues where geotechnical factors 

were of potential importance were identified:

• Direct, reliable, timely methods to measure 

scour. 

• Scour countermeasures. 

• Structure foundation types. 

• Unknown foundation types.

• Bridge bearings (all types).

• Jointless structures (integral, semi-integral, 

continuous for live load).

Within this range of topics, FHWA research 

and management personnel were concerned 

that geotechnical, foundation, and substructure issues had not been adequately captured. 

Therefore, the FHWA hosted the Workshop 

to Identify Bridge Substructure Performance 

Issues in Orlando, FL, during March 2010. FHWA 

personnel, LTBP Program research team, and 

approximately 30 invited attendees representing State transportation departments; FHWA 

headquarters, Federal aid, Federal lands, and 

research; academia; and consultants met to 

consider overall bridge performance and identify geotechnical performance metrics that may 

correspond to good and poor performance. 

The core of the workshop comprised breakout 

sessions to discuss three key elements of the 

program: bridge performance issues (affected 

by geotechnical factors); data needs and gaps 

(related to the issues identified); and tools, 

technology development, and monitoring 

(related to the data gaps). 

Based on the brainstorming of the three groups 

and the post-workshop discussions, the following short-term bridge performance priorities 

emerged (not in ranked order):

1. Approach and bridge interface issues.

2. Material degradation, corrosion, and deterioration issues. 

3. Mechanically stabilized earth (MSE) wall 

material degradation and assessment of 

wall integrity.

4. Hydraulics, scour, and erosion.

Further information on the Workshop to Identify 

Bridge Substructure Performance Issues and 
5

the findings from the workshop can be found 

in the report Summary Report on the FHWA 

LTBP Workshop to Identify Bridge Substructure 

Performance Issues (FHWA-HRT-11-037) and 

the TechBrief Summary Report on the FHWA 

LTBP Workshop to Identify Bridge Substructure 

Performance Issues (FHWA-HRT-13-049) held 

March 4-6, 2010, in Orlando FL.(1,2)

FHWA has established an LTBP State 

Coordinators Group with one key bridge representative from each of the States and Puerto 

Rico and the District of Columbia. The inaugural meeting of the LTBP State Coordinators 

was held in September 2011 to familiarize them 

with the scope and goals of the program and 

solicit their ideas and feedback on the conduct 

of the program. The list of high priority performance issues that was current at the time was 

presented to the group, and the coordinators 

provided input.

The AASHTO Subcommittee on Bridges and 

Structures (SCOBS) is an important stakeholder 

of the LTBP Program. Findings of the program 

that result in potential changes to specifications, inspection methods, bridge management 

practices, etc. will need to be endorsed by the 

relevant technical committees as well as the 

full SCOBS. Each year, FHWA has provided a 

briefing on the program to the full subcommittee. Also, briefings are frequently given to the 

relevant technical committees (i.e., T-5, Loads 

and Load Distribution; T-9, Bridge Preservation; 

T-11, Research; and T-18, Bridge Management, 

Evaluation, and Rehabilitation). During these 

briefings and discussions, the FHWA has 

received feedback about performance issues of 

interest or methods for pursuing the research 

objectives. These groups agreed that the performance issues presented were high priorities to 

study.

Under a contract with the National Academy 

of Sciences, FHWA has coordinated with TRB 

to organize and facilitate a TRB LTBP Advisory 

Committee, comprising members from government, industry, consultants, and academia, to 

provide feedback annually on the progress of 

the LTBP Program and recommendations on 

strategies for the program. At the first meeting 

of the TRB LTBP Committee in November 

2011, the members reviewed the high priority 

performance issues being recommended for 

study and subsequently informed FHWA of their 

concurrence on the proposed list.(3,4)

Conclusions and 

Recommendations

The LTBP Program is intended to be a longterm program to collect comprehensive information on bridge performance issues that will 

support improvements to bridge management 

practice and lead to improvements in bridge 

performance.

Bridge performance is a multifaceted issue 

involving performance of materials and 

protective systems, performance of individual 

components of the bridge, and performance 

of the structural system as a whole. Bridge 

performance is influenced by many factors; 

some are static or fixed (e.g., design type), and 

others are variable (e.g., live loadings). The 

LTBP Program’s resources may be inadequate 

to study every aspect of bridge performance. 

A basic principle governing the program is 

that it should serve the needs of bridge owners across the Nation as identified by those 

bridge owners. Thus, considerable effort was 

undertaken to solicit input from bridge owners 

as well as from the bridge community at large 

on what high priority bridge performance issues 

should be addressed by the LTBP Program. The 

State transportation departments, bridge technical committees, and other individuals interviewed also provided input on the types of data 

that should be collected by the program and 

on the types of decision support tools that the 

program should deliver.

The result of the focus group meetings and 

other interviews is a list of 22 high priority 

bridge performance issues recommended 

for study under the LTBP Program. Table 1 

presents the comprehensive list of topics 

after considering all input from stakeholders.
6

After discussions among the research team, 

FHWA, State coordinators, and the TRB LTBP 

Committee, it was recognized that all topics 

could not be addressed immediately and the 

number of topics to be addressed would be 

constrained by program resources. Therefore, 

a short list of top priority topics was developed. 

Table 2 presents the initial six top priority topics recommended for study under the program.

As time and resources permit, additional topics 

may be incorporated into the program. These 6 

issues and the majority of the other issues in the 

Table 1. Long-term bridge performance suggested study topics.

Category LTBP Bridge Performance Topic

Decks

Performance of Untreated Concrete Bridge Decks

Performance of Bridge Deck Treatments

Performance of Precast Reinforced Concrete Deck Systems

Performance of Alternative Reinforcing Steels

Influence of Cracking on the Performance of High-Performance Concrete 

Decks

Joints

Performance of Bridge Deck Joints

Performance of Jointless Structures

Bearings Performance of Bridge Bearings

Concrete Bridges

Performance of Bare/Coated Concrete Super- and Substructures

Performance of Embedded Prestressing Wires and Tendons

Performance of Prestressed Concrete Girders 

Performance of Impact-Damaged Concrete and Prestressed Concrete Beams

Steel Bridges

Performance of Coatings for Steel Superstructure Elements

Performance of Weathering Steels

Performance of Impact-Damaged Steel Beams

New Construction Performance of Innovative Bridge Designs and Materials

Foundations & Scour

Performance of Scour Countermeasures

Performance Issues at the Bridge Approach-Abutment Interface 

Performance of Substructure Components

Performance of MSE Walls

Risk Risk and Reliability Evaluation for Structural Safety Performance

Functional Performance of Functionally Obsolete Bridges
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list of 22 are all related primarily to the physical 

condition and the structural integrity of bridges. 

They represent issues that bridge owners most 

commonly face in maintaining, repairing, or 

rehabilitating their bridges and involve the most 

common maintenance, repair, or rehabilitation activities they need to perform. These performance issues may arise because of certain 

design and/or construction details or may be the 

result of or be aggravated by service conditions 

and loadings.

The identification of the high priority issues is 

the basis of other major elements of the LTBP 

Program, including the following:

• Determining what knowledge and data 

related to these issues are readily available 

from other sources.

• Determining what critical knowledge and 

data gaps exist and what types of testing 

and investigation are needed to fill those 

gaps.

• Selecting representative samples of bridges 

that will be the source of the missing 

knowledge and data.

• Designing experiments for collection, 

storage, and analysis of the data.

• Designing the data infrastructure to store 

and manage the data. 

Each of the high priority performance issues 

will be examined in detail, and the specific data 

necessary to study the issues will be identified. The results will be published in the 

upcoming report Identifying Long-Term Bridge 

Performance Data Needs.

Additional Information

For additional information, contact: Susan Lane, 

HRDI-60, (202) 493-3151, susan.lane@dot.gov. 

Table 2. Initial study topics for the LTBP Program.

Category Issue

Decks Untreated Concrete Bridge Decks

Decks Treated Concrete Bridge Decks

Joints Bridge Deck Joints

Bearings Bridge Bearings

Steel Bridges Coatings for Steel Superstructure Elements

Prestressed Concrete 

Bridges Detection of Condition of Embedded Pretensioned Strands and Post-Tensioning Tendons
Researchers—This study was performed by Rutgers, the State University of New Jersey; 

the Virginia Center for Transportation Innovation and Research; Virginia Tech; and Parsons 

Brinckerhoff. 

Distribution—This TechBrief is being distributed according to a standard distribution. Direct 

distribution is being made to the Divisions and Resource Center.

Availability—This TechBrief may be obtained from the FHWA Product Distribution Center by 

e-mail to report.center@fhwa.dot.gov, by fax to (301) 577-1421, by phone to (301) 577-0818, or 

online at http://www.fhwa.dot.gov/research/tfhrc/programs/infrastructure/structures/

ltbp/pubs.cfm.

Key Words—LTBP Program, bridge performance, bridge testing, bridge inspection

Notice—This document is disseminated under the sponsorship of the U.S. Department of 

Transportation in the interest of information exchange. The U.S. Government assumes no 

liability for the use of the information contained in this document. The U.S. Government does 

not endorse products or manufacturers. Trademarks or manufacturers’ names appear in this 

report only because they are considered essential to the objective of the document.

Quality Assurance Statement—The Federal Highway Administration provides high-quality 

information to serve Government, industry, and the public in a manner that promotes public 

understanding. Standards and policies are used to ensure and maximize the quality, objectivity, 

utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its 

programs and processes to ensure continuous quality improvement.

JUNE 2014 FHWA-HRT-14-043

HRDI-60/06-14(750)E

8

References

1. Schaefer, V, Maher, A., Hooks, J., and 

Foden, A. (2013). Summary Report on the 

FHWA LTBP Workshop to Identify Bridge 

Substructure Performance Issues: March 

4–6, 2010, in Orlando, FL, Report No. FHWAHRT-11-037, Federal Highway Administration, 

Department of Transportation, McLean, VA.

2. Hooks, J. (2013). TechBrief: Summary Report 

on the FHWA LTBP Workshop to Identify 

Bridge Substructure Performance Issues: 

March 4–6, 2010, in Orlando, FL, Report 

No. FHWA-HRT-13-049, Federal Highway 

Administration, McLean, VA

3. First Letter Report of the TRB Long-Term 

Bridge Performance (LTBP) Committee, 

March 16, 2012.

4. FHWA Response to First Letter Report of the 

TRB Long-Term Bridge Performance (LTBP) 

Committee, May 30, 2012.