116 at Green Valley Road Intersection Improvement Project

Caltrans is studying a project to improve safety at the intersection of State Route 116 and Green Valley Road in Graton, located on the north side of Sebastopol in Sonoma County.  

The current intersection is controlled by two stop signs on each side of Green Valley Road.  Route 116 is not controlled by signs or signals at Green Valley Road. 

Caltrans traffic engineers have found the collision rate to be higher than similar intersections in California, particularly broadside collisions which have a high injury rate.   

To reduce the collision rate, Caltrans has explored two alternatives: Constructing a roundabout or installing traffic signals. 

For more information on the project, click on the links below: 

 

Explore the Project

Environmental Document

 

Public Meeting

Caltrans held a community meeting on November 19, 2025, from 6:30 PM to 8:30 PM at the Graton Fire Department, 3750 Gravenstein Highway N, Sebastopol.  Over 80 people attended the meeting.