Final Scope

A significant number of bridges on the national inventory are being replaced yearly by state departments of transportation (DOTs). Many of those replacement bridges are on critical arteries necessitating complex and, in some cases, costly strategies and construction techniques.  The resulting techniques for replacing the bridge need to balance the goals of maintaining mobility, work zone safety, construction quality and environmental impacts, along with budgetary and schedule constraints.

Typical bridge replacement construction strategies and techniques for complex scenarios may include:

• Staged construction;
• Construction of the new bridge off the existing alignment and shifting traffic;
• Accelerated Bridge Construction techniques minimizing disruption;
• Temporary bridges (diversions or runarounds); 
• Closure and full detour; and,
• Other strategies state DOTs use.

State DOTs will consider a variety of factors when deciding how to approach the bridge replacement project, such as:

• Existing and proposed bridge geometrics/properties, structure type;
• Average Annual Daily Traffic (e.g. percent truck traffic, pedestrian impact);
• Detour out-of-distance travel;
• Site characteristics (e.g. hydraulic, geotechnical, geometric requirements, archaeology);
• Environmental impacts (e.g. environmental justice, wildlife habitat, endangered species, water and soil contamination);
• Right-of-way procurement, temporary and permanent;
• Material type, availability, and quality;
• Construction season (weather), duration of project;
• Construction techniques and quality;
• Demolition constraints;
• Roadway safety;
• Asset life-cycle cost;
• Stakeholder input;
• Direct cost;
• Indirect cost;
• Funding constraints;
• Asset life-cycle cost;
• Contract period strategy (e.g. working days, calendar days, incentive/disincentive, A+B); and
• Project delivery method (e.g. design-bid-build, design-build, CMGC, P3).

The objective of this synthesis is to document practices and decision-making used by state DOTs for planned bridge replacements in complex scenarios.

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

• Construction strategies and techniques state DOTs use to construct bridge replacements;
• Factors and constraints state DOTs consider when choosing the appropriate bridge replacement construction strategies and techniques; and
• Written policies, rubrics, guidelines, metrics, and tools state DOTs use for bridge replacement decision-making in complex scenarios.

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.

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

Meeting Dates
First Panel: September 21, 2023, Washington, DC
Teleconference with Consultant: October 24, 2023, 11 am - Noon Eastern 
Second Panel: May 30, 2024, Washington, DC, Keck Center

Panel Members

Glenda Diaz, Florida Department of Transportation

Donn Digamon, Georgia Department of Transportation

Ernest Kuhs, Pennsylvania Department of Transportation

James Nelson, Iowa Department of Transportation

Michaela Petersen, Washington State Department of Transportation

Laura Shadewald, Wisconsin Department of Transportation

Tuong Linh Warren, Federal Highway Administration (FHWA)

Nelson Gibson, Transportation Research Board