State overcomes challenges by prioritizing historic bridges

Posted in: Bridges, Cultural Resources, Transportation

big-bridge_bodyHistoric bridges have a wide range of engineering challenges, including structural deterioration, inadequate load capacity and poor geometrics. Rehabilitating these bridges is difficult, as tight funding is a major limitation for owners and state transportation agencies. We’ve found success by helping owners prioritize and invest in historic bridges that can fill ongoing transportation needs which makes it easier to find funding. One such effort helped the Louisiana Department of Transportation and Development focus its limited resources on an important set of historic bridges that are now classified as Preservation Priority.

The state’s commitment to preserve certain historic bridges is a key term within the Section 106 Programmatic Agreement executed in September 2015. Louisiana’s newly adopted Management Plan for Historic Bridges Statewide sets forth the details of this effort, providing guidance to bridge owners on how to properly undertake preservation activities for historic bridges to support their continued transportation use.

Major components of the statewide management plan include:

  • Recommended treatments for historic bridges, applying the Secretary of the Interior’s Standards for the Treatment of Historic Properties and the collaborative team approach where an engineer and historian jointly prepare plans.
  • Technical guidance on preventative maintenance and rehabilitation activities, cost estimating and applicability of design exceptions.
  • Additional resources including guidelines, manuals, funding sources, historic bridge training and agency contacts to assist in historic bridge preservation projects.

small-bridge_bodySix workshops were offered in April through July where nearly 150 people were trained on the application of the Secretary of the Interior’s Standards to historic bridge rehabilitation projects. Other measures which support the program include preparation of individual bridge management plans for the 33 bridges identified as Preservation Priority Bridges and the preparation of Historic American Engineering Record documentation for each important bridge type in Louisiana.

Assistant State Bridge Engineer Ray Mumphrey provided his perspective on the advantages of the new program to the state:

In the past, navigating the individual 106 process to obtain environmental clearance was very time consuming and had many inefficiencies. The Programmatic Agreement (PA) allows us to begin the 106 process at the point where the eligibility of the structure has been determined and the importance (category) of the historic structure has been established. This can be a time savings of a few months.

Now that the PA is in place, the Department is able to focus on investing funds for rehabilitation and preservation activities on many of the preservation priority bridges. We plan on improving the condition of these structures while maintaining them for as long as possible.

By prioritizing and investing in historic bridges that are able to fulfill ongoing transportation needs, states like Louisiana are using limited resources to effectively focus their bridge preservation efforts. Through technical guidance and training, engineers and historians have the tools to work collaboratively to accomplish historic bridge projects in a manner that benefits both the regulatory and design process.

Amy Squitieri

About the Author

Amy Squitieri, an expert in historic bridges, helps states and bridge owners balance engineering needs for safety and good function with interests to preserve the legacy of the past. “Success is when an owner can reuse their existing infrastructure in a way that’s both functional and retains important aspects of engineering heritage,” says Amy. She leads Mead & Hunt’s Environment and Infrastructure Group.

Read more posts by Amy Squitieri

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