Phase 3A (2008 - 2014)
The third and final phase of the Golden Gate Bridge Seismic Retrofit Construction Project was separated into two sub-phases.
Phase 3A: Retrofit of the North Anchorage Housing and Pylon N1
Phase 3A cost $125 million and was funded using a combination of federal funds along with regional and state earmarks. A construction contract for Phase 3A was awarded in April 2008 and construction was completed in 2014.
Phase 3B (2026 - 2036)
Phase 3B: Retrofit of the Main Suspension Span, Main Towers, South Tower Pier and Fender
The final phase of the Golden Gate Bridge seismic retrofit, Phase 3B, includes strengthening the main span between the two towers and two side spans while reinforcing both towers and the south tower pier. The project will focus on the towers and side spans first because they are less flexible than the main span. That work includes strengthening the tower bases with large steel plates, strengthening the tower trusses, and replacing expansion joints where the roadway meets the towers and pylons to allow for three-dimensional movement in case of a large earthquake.
The project will strengthen the roadway by reinforcing lateral bracing, retrofitting 255 floor beams on the roadway, and installing 38 energy dissipation devices that greatly reduce the amount of seismic energy transferred to the Bridge. The project will also repaint the South tower above the roadway.
Due to the size of the project, Phase 3B will be completed under two consecutive construction contracts. The first construction contract for Phase 3B is $864 million and will be funded using a combination of federal, state, and District funds. The first construction contract for Phase 3B was awarded in October 2025 and will take approximately 6 years to complete. Construction is slated to begin in early 2026.