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.


  • 2017

    Environmental clearance; final design and right of way certification

  • 2023

    Construction start

  • 2026

    Construction complete

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 $116 million. Funding comes from a combination of federal, state and Treasure Island Development Authority funds.



Public engagement
An aerial image of the bridges on Yerba Buena Island

See the Transportation Authority's Feb. 8, 2021 presentation to the Civic Design Review Committee of the SF Arts Commission. The Transportation Authority is proposing an aesthetic treatment for the new retaining walls to be built during the West Side Bridges Retrofit.


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.