Starting November 3, 2025, Caltrans will begin one-way traffic control on State Route 121 south of Big Bend in Sonoma County. This is to replace the railings on the Yellow Creek Bridge. The work area is just south of the Highway 116/121 Roundabout. The project will last until February 28, 2026. During this time, the two-lane road will be reduced to one lane. Traffic will alternate under signal control.
Drivers traveling between Sonoma, Napa, and Petaluma may experience delays. Extra travel time is recommended, especially during busy hours. The Yellow Creek Bridge was built in 1922 and is being improved for safety. This project follows recent work on the Arroyo Seco Bridge. Drivers should use caution in the area and check Caltrans QuickMap for updates…