Updated: Lane Reductions Begin State Route 37 – Petaluma River Bridge, Marin County Monday, Oct. 12 until morning of Saturday, Oct. 17

Construction Project Duration-October 2026-Tentative July 2028

Marin County - Caltrans will begin a structural rehabilitation project on State Route 37 (SR-37) at the Petaluma River Bridge, at the Marin-Sonoma County line. The initial work will require weekday and weeknight single-lane reductions.

SR-37 Petaluma River Bridge

Beginning Monday, Oct. 12, through Friday, Oct. 17, one of the two lanes on both eastbound and westbound directions on SR-37 will be closed from 6 p.m. to 5 a.m. the following mornings.

At least one lane in each direction will remain open at all times. The lane closures will allow crews to restripe and place temporary concrete barriers.

Caltrans will announce additional lane closure times and locations as soon as information becomes available.

The entire project is expected to take approximately 2 years, depending on weather and other field conditions.

Work will include rehabilitating the bridge deck and upgrading the bridge barriers and railings to meet current safety standards.

This project focuses on rehabilitating the SR-37 Petaluma River Bridge and does not directly address long-term efforts to protect SR-37 from sea level rise.

Separate projects to reconstruct the nearby SR-37 Tolay Creek Bridge and SR-37 Novato Creek Bridge are tentatively scheduled to begin in 2027.

In August 2026, the California Transportation Commission (CTC) approved more than $300 million to advance sea-level-rise resilience projects throughout the SR-37 Corridor. These efforts mark the first set of SR-37 Corridor resilience projects moving forward.

For the latest updates on work at the SR-37 Petaluma River Bridge, visit: State Route 37 Petaluma River Bridge Preservation Project

For updates on upcoming Resilient SR-37 projects addressing sea-level-rise improvements, visit: SR37 Corridor Projects