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LTBP Data Collection


The Long-Term Bridge Performance (LTBP) Program is a long-term research effort to collect and make available high-quality bridge performance data on a nationwide basis that will help the bridge community better understand bridge performance. Products from this program include a suite of data-driven tools, including predictive and forecasting models that will enhance the ability of bridge owners to optimize their management of bridges.

The primary program objectives listed below are expected to improve the understanding of long-term bridge performance and result in more efficient bridge design, construction, rehabilitation, maintenance, preservation, and management.

Primary Objectives of the LTBP Program

The primary objectives of the LTBP Program are as follows:

  • To collect, manage, and provide easy access to data.
  • To perform in-depth data analysis.
  • To develop tools and products.

Since the initiation of the LTBP Program’s data collection efforts, many advances have been made in methods and automation for both collection and processing of various data types. With this in mind, the Federal Highway Administration’s (FHWA’s) LTBP Program managers conducted a data collection workshop in 2021 to receive input from bridge community subject matter experts who could assist with assessing the current and future LTBP Program’s data collection approaches. A summary report, Long-Term Bridge Performance Program Data Collection Workshop, describes the planning and conduct of the workshop (FHWA-HRT-22-015).

What Data is the LTBP Program Collecting?

The LTBP Program is collecting quantitative, research-quality bridge performance data on a national basis over time to help quantify the effects of external factors and internal attributes at the individual bridge and network level.

High Priority Bridge Performance Issues

Bridge performance is a multifaceted issue involving performance of: materials and protective systems, individual components of the bridge, and the structural system as a whole. The LTBP Program was initiated to collect, store, and analyze the data necessary to better understand high priority bridge performance issues. The success of the program depends on identifying the most important performance issues that bridge owners face. To identify these issues, feedback was sought from those bridge owners and other key stakeholders. As part of this outreach, bridge experts from 15 State transportation departments were interviewed and asked to name the performance issues in their bridge inventory that are most common and/or most difficult to solve. The findings of these interviews are included in report FHWA-HRT-14-052, LTBP High Priority Bridge Performance Issues, published in 2014.

To supplement these interviews and identify high priority issues related to bridge substructures, a workshop on substructure performance issues was held. The findings from the interviews and the substructure workshop were used to develop a list of 22 high priority performance issues. From this, a shorter list of six bridge performance issues was recommended as the first group of issues for study under the LTBP Program.

Based on input from stakeholders and considering current resources of the program, the following key topics in table 1 will be addressed initially:

Table 1. 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 the condition of embedded pretensioned strands and posttensioning tendons

Since 2014 when the high priority performance issues were identified, there have been many advances in data collection technologies and automation.  Therefore, in 2021 the LTBP Program conducted a data collection workshop to receive input from bridge community subject matter experts to assist FHWA in assessing the LTBP program’s future data collection approach (see report FHWA-HRT-22-015).  Analysis of the input received during the workshop as well as the lessons learned from past LTBP data collection efforts resulted in FHWA developing near-term and long-term data collection strategies.

Extensive resources and an optimized strategy are required to collect data to study the long-term performance of bridges. However, the strategy should not consist of gathering all desired data at any cost. It is imperative to determine the value of any data and how that data can be used when developing the LTBP’s future data collection approach. LTBP program staff continually assess the utility of all field and accelerated testing data that have been collected to date in order to guide the path forward for data collection.

Near-Term Data Collection

Three specific categories of near-term data collection activities were identified as potential areas for data collection.  The first category involves what is termed “desk audit” data collection which includes collecting data and documentation pertaining to:

  • Design and construction Data.
  • De-icing chemical application rates.
  • Inspection reports.
  • Maintenance/preservation/rehabilitation actions.
  • Chronological State policies (deicing chemical application, deck washing, deck/crack sealing, overlays, and other deck treatments).
  • New bridge construction/deck replacements.
  • Steel coatings.
  • Operational data.
  • Environmental data.
  • Joints and bearings.

The second category of near-term data collection identified was to collect field performance-related data through leveraging the efforts of external stakeholders with the use of LTBP protocols. The data provided to FHWA will be made available through InfoBridge™ (, the LTBP Program’s data and analysis portal.

The third category of near-term data collection-related activities identified was to complete the second phase of an accelerated bridge performance testing project which includes collecting performance data on bridge deck overlays.

Long-Term Data Collection

LTBP staff also identified three potential long-term data collection activities.  The first activity involves data collected by stakeholders and others with the use of LTBP protocols. The second activity involves conducting additional targeted accelerated testing of different bridge specimens. The third long-term data collection activity involves targeted and limited field data collection to be used primarily for validation purposes.

How is the LTBP Program Collecting Data?

To ensure that LTBP Program data are collected in a consistent manner over the duration of the program, data collection protocols are being developed by the Federal Highway Administration (FHWA) for use by practitioners, LTBP researchers, and decisionmakers involved with the research, design, construction, inspection, maintenance, and management of bridges. Report FHWA-HRT-16-007, Long-Term Bridge Performance (LTBP) Program Protocols, Version 1, was published in January 2016.

A set of approximately 185 LTBP Program data collection protocols have been developed covering visual inspection, material testing, and NDE.  The protocols address both the visual data collection and the manual data collection. Additional protocols will be developed to address desk audit-based data types identified above as well as potential revisions made to existing protocols to meet current needs.  

More information about the LTBP Program Protocols can be found on either the LTBP Research Projects and Products Page or on the LTBP Tools and Products Page.