New and Updated Statewide Historic Bridge Survey

Completed in 1995, the collaborative effort completed by the Iowa Department of Transportation (Iowa DOT), Federal Highway Administration (FHWA), and all Cities and Counties was the first statewide historic bridge study that inventoried all bridges in the state (with very few exceptions) that were built prior to 1942 (FraserDesign 1995). Prior to this effort LPAs and the Iowa DOT had to evaluate all bridges over 50 years old individually as part of the project development process under the National Historic Preservation Act. Under the premise that historical significance changes through time, historic preservation stakeholders such as the Iowa State Historic Preservation Office (Iowa SHPO) usually consider evaluations five years old or less valid. A substantial amount of grace was extended to the 1995 statewide bridge study. However, over the last several years it has become apparent that an update to the statewide bridge study is becoming increasingly necessary. Either funded with support from FHWA or permitted through the USACE, more and more LPAs are being asked to evaluate their historic bridges one by one (recent examples can be provided). We are likely entering a time were it will be much more effective (for both planning purposes and for costs) to complete an update to the statewide bridge survey whereby allowing LPAs to know if they are dealing with a historic bridge before they begin the project development process. Advancing the bridge inventory cut-off date to 1975 would maximize the long-term efficiencies that an update could provide. It’s recommended that LPAs and the Iowa DOT work to find a partnership that benefits all infrastructure owning agencies. Its important to note that the Iowa DOT did update its inventory of historic bridges in 2011, however, that effort only applied to primary system bridges. This effort will allow for submission to any federal agency requiring a historical review including Corps, FHWA, FEMA. All LPA's and Iowa DOT will benefit from this new updated study.


  • English


  • Status: Active
  • Funding: $1161941
  • Contract Numbers:


  • Sponsor Organizations:

    Iowa Department of Transportation

    800 Lincoln Way
    Ames, IA  United States  50010

    Iowa Highway Research Board

    Iowa Department of Transportation
    800 Lincoln Way
    Ames, IA  United States  50010
  • Managing Organizations:

    Bear Creek Archeology, Inc

    Cresco, Iowa   
  • Project Managers:

    Dolan, Brennan

  • Performing Organizations:

    Bear Creek Archeology, Inc

    Cresco, Iowa   
  • Start Date: 20230630
  • Expected Completion Date: 20250630
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01909014
  • Record Type: Research project
  • Source Agency: Iowa Department of Transportation
  • Contract Numbers: TR-819
  • Files: RIP, STATEDOT
  • Created Date: Feb 20 2024 7:03PM