Research for AASHTO Standing Committee on Highways. Task 397. Characteristics of Decommissioned Bridges

Bridge preservation activities have focused on the service life extension of bridge components or protection systems that extend the useful life of bridges. National efforts are underway to look at materials, design and construction practices to extend the useful life of bridges toward an elusive 100 year mark. Informal research done by the Transportation Research Board Bridge Preservation Committee (AHD037) using 20 years of National Bridge Inventory (NBI) data for all states in the United States indicates that the majority of bridge replacements may not be driven by the condition of the bridge. If the majority of bridges are not being replaced due to condition, then what is driving bridges to be taken out of service? Are bridge preservation efforts appropriately focused on the true factors that are leading to the premature replacement of bridges? Understanding what is causing bridges to be decommissioned will allow bridge managers to better adapt practices to achieve the maximum possible service life. The objective of this research project was to determine the driving causes of bridge decommissioning in the United States. TASKS - Task 1. Perform a synthesis of similar and related research on the topic of causes of decommissioning of bridges. Task 2. Conduct a survey of State departments of transportation (DOTs) to capture the policies and justifications for replacement of bridges. This survey should relate condition, performance, vulnerabilities and functional replacement justifications to associated NBI data. Task 3. Utilize nationwide National Bridge Inventory databases to analyze the characteristics of bridges in their last year in the inventory prior to decommissioning. Determine the expected service life of bridges based on material, design types, traffic volumes, truck volumes, geography, environmental conditions, functional classifications, and others. For bridges that are not structurally deficient at the time of decommissioning, determine the probable cause of the replacement by looking at alternative drivers, including by not limited to scour vulnerabilities, load capacities, vertical and horizontal clearances, and adequacy of service (level of service) of the roadway carried on the bridge. Task 4. Utilize the results from Task 2 to select three to four State Departments of Transportation where project level records exist to positively confirm the characteristic drivers for bridge replacement. This task will involve a review of agencies replacements and project records to determine the causes of replacements.  The state level results should be correlated to the national level results. Task 5. Present the research findings to the American Association of State Highway and Transportation Officials (AASHTO) Subcommittee on Bridges and Structures, Technical Committees: T-9 Preservation. Task 6. Summarize the findings from both national and state level reviews and recommend needed research areas to help achieve extended bridge service lives. Task 7. Submit the final report describing the entire research. Following receipt of the draft final report, the remaining 2 months shall be for the National Cooperative Highway Research Program (NCHRP) review and comment and for research agency preparation of the revised final report.


  • English


  • Status: Completed
  • Funding: $100000
  • Contract Numbers:

    Project 20-07, Task 397

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Dekelbab, Waseem

  • Performing Organizations:

    Iowa State University

  • Principal Investigators:

    Bektas, Basak

  • Start Date: 20170221
  • Expected Completion Date: 20180630
  • Actual Completion Date: 0
  • Source Data: RiP Project 41542

Subject/Index Terms

Filing Info

  • Accession Number: 01631591
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 20-07, Task 397
  • Files: TRB, RiP
  • Created Date: Mar 31 2017 1:00AM