An aerial image of the bridges on Yerba Buena Island


The West Side Bridges Retrofit will seismically retrofit eight existing bridge structures along Treasure Island Road to meet current seismic safety standards. One of the structures will be seismically retrofitted, while the remaining bridges will be demolished and replaced. These bridge structures are a critical connection between Yerba Buena Island, Treasure Island, and the Bay Bridge.

This project is part of the I-80 Interchange Improvement Project, an effort to replace and retrofit key roads and on- and off-ramps that connect the I-80 (the highway on the Bay Bridge) and Yerba Buena Island. The Transportation Authority is working jointly with the Treasure Island Development Authority and the Office of Economic and Workforce Development on this effort. These upgrades will support the Treasure Island Transportation Program.

Timeline & Status 

The Transportation Authority completed the environmental clearance in fall of 2017 and has been continuing with preliminary engineering. Final design and right of way certification activities are targeted for completion in 2021. The project is currently anticipated to start construction in 2021, with completion targeted by 2024.

Project Partners

The Transportation Authority is leading the design and construction of this project in collaboration with the Treasure Island Development Authority.

Cost & Funding 

The total cost of the West Side Bridges Retrofit is $82,900,000. Funding comes from $73,400,000 in federal funds, $7,200,000 in state funds, and $2,300,000 from the Treasure Island Development Authority.


Eric Cordoba, Deputy Director for Capital Projects

Related programs

The Treasure Island Transportation Program will address the island's growing transportation needs with a goal to have at least 50 percent of trips made by transit instead of private vehicles.

The new westbound I-80 on- and off-ramps that connect Yerba Buena Island and Treasure Island to the eastern span of the Bay Bridge are open.

Vista Point is a scenic rest stop on Yerba Buena Island near the Bay Bridge east span bicycle/pedestrian path.

The Southgate Road Realignment will realign Southgate Road, the critical local road connection between the I-80 westbound and eastbound on- and off-ramps.