Southgate Road on Treasure Island


The Southgate Road Realignment will realign Southgate Road, the critical local connection between the I-80 westbound and eastbound on- and off-ramps, and reconstruct and reopen the I-80 eastbound off-ramp to Yerba Buena Island. 

This project is part of a larger 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.

Project Map

An aerial view of the new road configuration

Timeline & Status 

Environmental clearance, final design, and right of way certification are complete. Construction began in June 2020 and completion is expected in 2022.  


Cost & Funding 

The Southgate Road Realignment project will cost $63.7 million. Funding comes from the Federal Highway Bridge Program, State Prop 1B, the Bay Area Toll Authority, and the Treasure Island Development Authority.


Eric Cordoba, Deputy Director for Capital Projects

Key features

The Southgate Road Realignment project will: 

  • Add a new eastbound off-ramp to Yerba Buena Island from the slow lane of I-80
  • Separate traffic heading to westbound and eastbound I-80, eliminating vehicle queuing onto I-80
  • Provide direct access from Hillcrest Road to the westbound on-ramp
  • Widen and improve Hillcrest Road 
  • Ensure that all truck turning movements are accommodated 
  • Construct a bike and pedestrian path. 

The second major capital project delivered by the Transportation Authority, the project will provide vital infrastructure for the growing San Francisco neighborhood. (The first major capital project was the I-80 East Side Ramps Project.)

Disadvantaged Business Enterprise goal: The construction firm hired for the project, Ghilotti Construction Company Inc., has committed to direct almost 17 percent of the budget to disadvantaged business enterprises. Work for DBE firms may include demolition, excavation, erosion control, noise monitoring, landscaping, traffic control, and trucking. 

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.

The West Side Bridges Retrofit will seismically retrofit eight existing bridge structures along Treasure Island Road to meet current seismic safety standards.

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