Contact: Eric Young, Communications Director, (415) 306-4509 cell

The San Francisco County Transportation Authority, in partnership with FHWA, Caltrans, BATA, and the Treasure Island Development Authority, announced the start of construction on the I-80/Yerba Buena Island West Side Bridges Retrofit Project.

The $126 million project, expected to be completed in 2026, is funded by federal, state, regional and local grants and improves circulation and safety for motorists as well as people biking and taking transit.

The project features:

  • Seismic upgrades to retrofit eight existing bridge structures along Treasure Island Road on the west side of Yerba Buena Island and I-80 Bay Bridge ramp improvements to meet current operational safety standards;
  • Expanded bicycle access by creating a 6-foot wide bicycle lane with a striped safety buffer. The bikeway is the first step in the Bay Skyway Phase 1 project that will link both Treasure Island and Yerba Buena Island with the Transbay Bay Trail slated for the Bay Bridge;
  • Improved bus access to the Islands with a dedicated west-bound bus/HOV (high-occupancy vehicle) on-ramp to the Bay Bridge; and
  • Decorative retaining wall designed by Bay Area artist Muzae Sesay

The West Side Bridges Retrofit project is the third in a trio of ramp seismic safety projects led by the Transportation Authority designed to rebuild key roads and ramps linking the islands to the I-80 San Francisco-Oakland Bay Bridge. The first project was the I-80 East Side Ramps project, completed in 2016. The second was the Yerba Buena Island/I-80 Southgate Road and Interchange Project, completed in 2023.

The West Side Bridges Retrofit will take advantage of an alternative project delivery method known as the Construction Management/General Contractor process. Using the CM/CG process, the project’s owner (the Transportation Authority) hires a contractor to provide feedback during the design phase and before the start of construction. Early contractor involvement means the contractor’s perspective can be integrated into planning and design decisions, which can help improve project designs and delivery outcomes.

“The West Side Bridges Retrofit project will strengthen critical Bay Area connections, create good-paying construction jobs and expand public transit to Yerba Buena and Treasure islands,” Speaker Emerita Nancy Pelosi said. “With today’s groundbreaking, the Bay Area is one step closer to completing vital upgrades for bridges to Yerba Buena and Treasure islands – and it was my privilege to work with the U.S. Department of Transportation to secure more than $18 million in a RAISE grant for this important project. Thanks to Democrats’ Infrastructure Law, new investments will continue to provide federal funding needed to help communities across the country build stronger and more sustainable infrastructure.”

“I’d like to thank our federal delegation and project delivery and funding partners for their support in delivering this world class infrastructure for Treasure Island,” said Transportation Authority Board Chair Rafael Mandelman (District 8). “The seismic safety and multi-modal transportation benefits will greatly improve access for the planned 8,000 new units of housing on Treasure Island.”

“The completion of this project will not only bring the Bay Trail to Yerba Buena and Treasure Islands, but also better integrate the islands with the rest of the Bay Area,” said Andrew Fremier, Executive Director of the Metropolitan Transportation Commission. “The multimodal access the West Side Bridges project will deliver brings us a big step closer to achieving the connectivity and sustainability goals envisioned in Plan Bay Area 2050.”

“I applaud the Transportation Authority for supporting economic redevelopment and helping improve access to our vibrant neighborhood,” said V. Fei Tsen, President, Treasure Island Development Authority Board. “Constructing six new retaining walls will greatly improve the Islands’ resilience to natural events and multimodal accessibility.”

During the retrofit project, the left lane eastbound exit from the Bay Bridge to Treasure Island will be closed starting the early morning of Thursday, June 22. Drivers will be directed to use the newly-built right lane Bay Bridge Southgate Road off ramp to Yerba Buena Island which opened May 7, 2023 for alternate access to the Islands. Also, starting Monday, June 26, the existing westbound Bay Bridge on-ramp will close and drivers should use Macalla Road to access the Yerba Buena Island East Side on-ramp.

Learn more at the project website.

Project rendering

Rendering of the newWest Side Bridges, connecting Treasure Island Road to Hillcrest Road and the Bay Bridge



About the San Francisco County Transportation Authority (

The San Francisco County Transportation Authority’s mission is to make travel safer, healthier, and easier for all. We plan, fund, and deliver local and regional projects to improve travel choices for residents, commuters, and visitors throughout the city. The Transportation Authority Board consists of the 11 members of the San Francisco Board of Supervisors, who act as Transportation Authority Board Members. Board Member Rafael Mandelman is Chair of the Board. Tilly Chang is the Transportation Authority’s Executive Director.