Sonoma 121 Safety Improvements Project


SCH Number
Lead Agency
Caltrans 4 (Oakland) (California Department of Transportation, District 4)
Document Title
Sonoma 121 Safety Improvements Project
Document Type
NEG - Negative Declaration
Present Land Use
transportation corridor

Document Description
The purpose of this safety project is to reduce occurrences of cross-centerline collisions. The project is divided in 3 segments. Segments 1 and 3 both have drainage work, and segment 3 is proposed to have the MBGR upgraded to MGS. For segment 2, there are two proposed alternatives for roadway realignment. For alternative 1, the proposed alignment would shift slightly towards the eastern side of SR 121 and there would be two retaining walls on the eastern side and a two-way left turn lane after the entrance to a winery business. For alternative 2, the horizontal curve will be straightened towards the western side of SR 121, and then realigned to the eastern side of the highway; two retaining walls are proposed, one on the eastern side and one on the western side of SR 121. Segments 1 and 3 are identical in both build alternatives.

Contact Information
Arnica MacCarthy
California Department of Transportation, District 4
111 Grand Avenue
Oakland, CA 94623-0060

Phone : (510) 286-7195


Cross Streets
Arnold Dr (SON 121) and Bisso Rd
Parcel #
128-451-040, 142-122-001
State Highways
SR 121
Other Location Info

Notice of Completion

Review Period Start
Review Period End
Development Type
Transportation:Other (roadway safety improv)
Project Issues
Aesthetic/Visual Agricultural Land Archaeologic-Historic Biological Resources Noise Public Services Toxic/Hazardous Traffic/Circulation Vegetation Water Quality Wetland/Riparian Land Use
Reviewing Agencies
Air Resources Board, Transportation Projects California Department of Parks and Recreation California Highway Patrol Caltrans, Division of Aeronautics Department of Conservation Department of Fish and Wildlife, Region 3 Department of Water Resources Native American Heritage Commission Office of Historic Preservation Regional Water Quality Control Board, Region 2 Resources Agency State Lands Commission State Water Resources Control Board, Division of Water Quality State Water Resources Control Board, Division of Water Rights
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