Traffic Detour for Mendocino Ave Overcrossing Project

In late April 2025, Caltrans will begin a $10 million project to replace railings on four Highway 101 overcrossings in Sonoma County: Mendocino Avenue, Shiloh Road, Fulton Road, and Limerick Lane.

Ghilotti Construction Company is the contractor on the project, which is estimated to take a year to complete. The contractor will stage the project so work will be ongoing simultaneously at the four overcrossings.

Caltrans will replace the bridge railings that line these overcrossings because they are decades old, show wear and tear from the weather, and fall short of current safety standards.

Westbound Closure on Mendocino Avenue

For safety reasons and to provide room to work, westbound Mendocino Avenue will be closed at the overcrossing for one year. Traffic will detour south and cross Highway 101 at Bicentennial Way.

Eastbound traffic will remain open during the entire project.

Old and New Railings and Barriers

The current railing on the south side of Mendocino Avenue is a banister-style railing, while the tubular barrier runs along the north side. Caltrans will replace both railings with a concrete barrier that will be safer and easier for work crews to maintain. (See photos below)

Caltrans will affix a banister-style railing to the top of the concrete barriers as an architectural element. (See example on Baker Avenue Overcrossing)

Detour maps and additional project details will be shared as they become available from Caltrans.