Final Scope

State departments of transportation (DOTs) recognize that management and maintenance practices for existing roadway and embankment culverts fundamentally influence culvert performance and have subsequent impacts on adjacent assets and overall transportation system performance. State DOTs actively research and implement methods to reduce costs, identify and reduce risk, minimize maintenance, improve performance, and ultimately increase the longevity of culverts.

The needs of state DOTs to reduce culvert degradation impacts and improve resilience are common, yet the approaches may be diverse. Variability in climate, climate events, seismic susceptibility, slope and embankment stability, watershed characteristics, and urban development and land uses create system challenges. Although the demands that state DOTs face vary significantly, commonalities exist, and practices used to enhance the resiliency of culverts can be broadly employed. This synthesis will provide awareness of management and maintenance practices used by other state DOTs to address and improve the performance and resiliency of their existing culverts.

Culverts were frequently identified and assessed as vulnerable components to extreme events and climate change during a 2013-2015 pilot study (FHWA-HEP-16-079). Documenting practices and remedial measures for culvert management and maintenance is an important step in planning for improved system operations, performance, and resilience.

The objective of this synthesis is to document management and maintenance practices used by state DOTs to enhance resiliency of existing roadway and embankment culverts.

Information to be gathered includes (but is not limited to):

• Assessment methodologies to evaluate cost/benefit and lifecycle cost for resiliency improvements;
• Identification and prioritization process and practice of culvert maintenance (e.g. practices to protect inlet and outlet basins from erosion);
• Remedial maintenance measures employed to improve culvert resilience, such as culvert liners, invert repairs, joint repairs, cathodic protection;
• Proactive culvert maintenance practices;
• Existing risk-management strategies to assess and prioritize the criticality and vulnerability of culverts;
• Identification of resilience issues related to culvert types (e.g. circular/box/arch) and materials (flexible/rigid);
• Practices that mitigate against piping at outlets and soil loss through joints due to pressure heads induced by storm event flooding and inundation;
• Practices addressing embankment overtopping;
• Practices addressing coastal impacts, including inundation and storm surge; and
• Existing post-event response practices and repair strategies for damaged culverts.

For the purpose of this scope, culvert is defined as a drainage conduit under a roadway or embankment that is open at both ends for the conveyance of water, excluding enclosed drainage systems. Resilience is defined as the ability to anticipate, prepare for, or adapt to conditions or withstand, respond to, or recover rapidly from disruptions, from FHWA-HIF-23-010.

Information will be gathered through a literature review, a survey of state DOTs, and follow-up interviews with selected DOTs for the development of case examples. Information gaps and suggestions for research to address those gaps will be identified.

Information Sources (Partial):

• NCHRP Report 473: Recommended Specifications for Large-Span Culverts (2002).
• NCHRP Synthesis 472: FEMA and FHWA Emergency Relief Funds Reimbursements to State Departments of Transportation (2015).
• NCHRP Synthesis 474: Service Life of Culverts (2015).
• NCHRP Synthesis 581: Rehabilitation of Culverts and Buried Storm Drain Pipes (2022).
• NCHRP Web-Only Document 190: Structural Design of Culvert Joints (2016).
• FHWA-HEP-16-079 - 2013-2015 Climate Resilience Pilot Program: Outcomes, Lessons Learned, and Recommendations (2016-2017).

TRB Staff (Consultant)
Sandra Larson
Phone: 515-971-6329
Email: slarson@nas.edu

Meeting Dates
First Panel: October 4, 2023, Washington, DC
Teleconference with Consultant: October 24, 2023, 3-4 pm Eastern 
Second Panel: June 25, 2024, Washington, DC, Keck Center

Panel Members

Luke Assink, Washington State Department of Transportation

Shunyi Chen, North Carolina Department of Transportation

Jeffrey DeGraff, Vermont Department of Transportation

Jimmy Duong, California Department of Transportation

Lindsey Merrifield, Maine Department of Transportation

Michelle O'Neill, Michigan Department of Transportation

Mary Lou Ralls Newman, Ralls Newman, LLC

David R. Claman, Federal Highway Administration (FHWA)

Nelson Gibson, Transportation Research Board