West Mission Bay Drive Bridge

The West Mission Bay Drive Bridge over the San Diego River project is the largest transportation infrastructure project executed by the City of San Diego. This vital transportation link connects Interstate 8 and Downtown San Diego to the south with Mission Bay Park, SeaWorld, and the beach communities to the north. 

The USD 148 million bridge replacement project, which included USD 80 million from the Bipartisan Infrastructure Law, replaced a structurally deficient bridge. The new crossing consists of parallel 1,300-foot-long structures that cross the San Diego River at a 45-degree skew. These structures carry three lanes of traffic, with standard shoulders and 12-foot-wide, barrier-separated shared-use paths in each direction. Two 14-inch-diameter sewer lines, a 20-inch-diameter water line, San Diego Gas & Electric distribution lines, and telecommunication lines are also supported within the bridge deck. All services remained operational throughout construction. 

The project was located within two miles of the Pacific Ocean and fell within Mission Bay Park, the Southwest Wildlife Preserve, and the city’s Multiple-Species Conservation Program. Numerous sensitive and endangered species were identified near the project limits area, requiring our significant coordination with regulatory agencies to resolve the many and often conflicting requirements.

Over 70 feet of soft saturated soils underlay the project and are subject to liquefaction or seismic softening during a seismic event. Drilled to depths of up to 175 feet, the large-diameter concrete piles are designed to resist forces from hazards such as earthquakes, liquefaction, floods, sea level rise, and tsunamis. 

Project Highlights:

• This project demonstrates how TYLin assists public agencies to improve mobility and achieve safety in a coastal environment while protecting environmental resources and enhancing scenic beauty.

• As Prime Consultant, we led the design team through all project phases, including completing the Plans, Specifications, and Estimates, all supporting studies, and gaining approvals for all deliverables to allow construction to proceed.

• Scope of work included close coordination with multiple agencies, including the City of San Diego, California Department of Transportation, U.S. Army Corps of Engineers, California Coastal Commission, U.S. Fish and Wildlife, California Department of Fish and Wildlife, and Regional Water Quality Control Board.

• Context-sensitive architectural features include earth-toned colors, visually permeable railings, deck and pathway lighting, and scenic overlooks with benches to create a beautiful bridge from all vantage points. 

• Advanced materials such as polymer fiber concrete, epoxy-coated and stainless-steel reinforcement, substitute cementitious materials, and powder-coated aluminum were used to minimize corrosion and extend the service life.