Caltrans Completes Two-Thirds of SFOBB West Span; Phase 3 Starts March 8

Caltrans announced on March 5, 2026 that it had completed Phase 2 of the San Francisco–Oakland Bay Bridge West Span Expansion Joint Rehabilitation project, finishing about two-thirds of the lower-deck reconstruction, and that Phase 3 work was scheduled to begin March 8, 2026. The agency confirmed the program began in August 2025 and remains on a timeline that targets overall construction completion by June 2027.

Phase 2 delivered the bulk of the lower-deck joint reconstruction and included installation of temporary underdeck platforms that supported the repairs. Caltrans posted on Instagram, "Caltrans has officially wrapped up Phase 2 of the San Francisco Oakland Bay Bridge West Expansion Joint Rehabilitation Project." The temporary underdeck platforms now slated for removal will give way to a new set of temporary elements during Phase 3.

Phase 3, beginning March 8, will remove the temporary underdeck platforms installed during Phase 2 and install temporary deck plates on the west end of the bridge toward San Francisco. Bay Area Metro material specifies that the temporary deck plates will be placed between the W2 and W3 towers. Caltrans also will install a temporary mid-span platform in Span C–D, identified as W4–W5, with that mid‑span installation underway through May 2026. Bay Area Metro states the temporary deck plates will remain in place through May 2026.

Maritime and vertical clearance impacts differ by installation activity and source. Caltrans warned that a truck will be used for installation during Phase 3, "temporarily reducing vertical clearance by approximately 15 feet at the span location." Separately, Bay Area Metro notes that "prior to installing temporary deck plates, temporary platforms will be placed under the lower deck, reducing shipping channel clearance by 2 feet 8 inches once installed." Caltrans added, "Caltrans appreciates the cooperation of the maritime community during this essential safety and rehabilitation work."

Construction for the West Span joint rehabilitation occurs mostly during nighttime hours, according to project materials, limiting daytime traffic disruption. The West Span is described in Bay Area Metro and MTC context as more than 85 years old, handling over 3 million cars per month and carrying 1.5 times more vehicles per lane than any other Bay Area bridge. Bay Area Toll Authority oversight remains central: BATA manages maintenance of the region’s seven state-owned toll bridges and funds work with toll revenue tied to "more than 342,000 paid trips each day."

Caltrans is advising motorists to check the agency’s highway projects pages for the latest construction information, traffic impacts, and detour details as Phase 3 proceeds. For questions tied to toll-bridge program management, Bay Area Metro identifies Ray Woo, BATA Program Coordinator, at rwoo@bayareametro.gov and 415-778-5337. Temporary installations for Phase 3 are expected to remain in place through May 2026, with the broader rehabilitation work carried to the June 2027 completion target.