CONTACT: Stephen Chun, SFCTA; 415-522-4816 office; 415-306-4509 mobile,

The California Transportation Foundation yesterday awarded the Transportation Authority the Interchange Project of the Year Award for the Yerba Buena Island / I-80 Southgate Road and Interchange Project. This project reconstructed the I-80 eastbound off- and on-ramps to and from Yerba Buena Island and features an innovative design that enhances safety and multi-modal traffic circulation.

The project is part of a larger effort to replace and retrofit key roads and ramps that connect the I-80 (the San Francisco-Oakland Bay Bridge) and Yerba Buena Island.

Developed in collaboration with the Treasure Island Development Authority, Caltrans and Bay Area Toll Authority (BATA), the Southgate project features an intricate design that has improved traveler safety for motorists, cyclists and pedestrians and enhanced traffic circulation on a challenging site by:

  • Upgrading the I-80 Bay Bridge eastbound off-ramp to seismic standards and building connections to the Transportation Authority’s award-winning YBI East Side Ramps Project that provided new westbound Bay Bridge access to the Islands in 2016;
  • Separating local vehicle traffic heading to westbound and eastbound I-80/Bay Bridge lanes and minimizing conflicts with cyclists and pedestrians; 
  • Creating dedicated bicycle and pedestrian facilities that connect East Bay travelers arriving to Yerba Buena Island Vista Point (from the Bay Bridge East Span Bike/Pedestrian path) to Treasure Island via Macalla Road; and
  • Managing vehicular speed while ensuring that all motor vehicle and truck movements are accommodated in the area.

“We thank CTF for recognizing the innovative design and outstanding delivery of the I-80 Yerba Buena Island Southgate Road and Interchange project,” said Transportation Authority Chair Rafael Mandelman. “We are grateful to our design and construction team, including HDR (design), MNS Engineers (construction management) and Ghilotti Construction Company (construction), and funding partners at Caltrans, BATA and the California Transportation Commission, for collaborating with us on this world class multimodal infrastructure that will benefit the growing communities on Treasure Island and Yerba Buena Island, and regional visitors, for years to come.”

Partner agencies also included the U.S. Coast Guard and city departments including the Treasure Island Development Authority, San Francisco Public Works, San Francisco Municipal Transportation Agency, and the San Francisco Public Utilities Commission.

The $63.7 million project was funded by the Federal Highway Bridge Program and State Prop 1B program, facilitated by Caltrans, with local matching funds provided by the Bay Area Toll Authority, and the Treasure Island Development Authority.

The project is the second of three projects led by the Transportation Authority designed to replace and retrofit key ramps linking the islands to I-80. The first project was the I-80 East Side Ramps project, completed in 2016. The Transportation Authority is currently leading the West Side Bridges Seismic Retrofit which began construction in June 2023.

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.