Caltrans has announced that one-way traffic control will be in effect on State Route 121 south of Big Bend from Monday, November 3, 2025, through Saturday, February 28, 2026, to replace the bridge railings on the Yellow Creek Bridge in the Schellville area of Sonoma County.
The work zone is located several hundred feet south of the newly opened Highway 116/121 Roundabout at Big Bend. During construction, the two-lane roadway will be reduced to a single lane, with northbound and southbound traffic alternating through the area under signal control. Motorists are advised to expect minor delays and to allow additional travel time, especially during commute hours.
While the project area is outside the City of Sonoma, local residents and commuters may experience traffic impacts when traveling between Sonoma, Napa, and Petaluma. Travelers are encouraged to use caution in the work zone and to check Caltrans QuickMap for real-time traffic updates before driving: http://quickmap.dot.ca.gov.
The Yellow Creek Bridge, built in 1922, is receiving safety upgrades as part of a two-bridge improvement project. Caltrans recently completed similar work on the nearby Arroyo Seco Bridge near 8th Street East.