State Route 20 Salt Creek Canyon
Project Description:
The California Department of Transportation proposes a safety improvements project in Colusa County on State Route 20 extending from the Colusa/Lake County line, Post Mile 0.0 to Interstate 5 Intersection, Post Mile R22.1.
Project Map Location:
Purpose:
The project aims to enhance safety for the traveling public and reduce the severity of collisions along this corridor.
Segments of SR 20 within the project limits have non-standard vertical and horizontal curves that limit sight distance. Existing clear recovery zones do not meet current Highway Design Manual (HDM) guidelines. The existing shoulder widths do not provide sufficient space to accommodate pedestrians, bicyclists, disabled vehicles, emergency, and enforcement activities.
Most existing flexible pavement is projected to be in fair conditions by the construction year. However, the pavement condition is anticipated to further deteriorate over time requiring prompt and continuous maintenance.
This route provides necessary freight access to the Clear Lake areas extending north to many smaller isolated communities. The State Highway System (SHS) needs to provide a lifeline for this area to essential services in both Clear Lake and Colusa areas like hospitals, airports, goods, and services. It also provides access to local commerce who rely on the SHS to access local commodities and services.
Justification
A Road Safety Audit was conducted along SR 20 corridor from the Lake County line PM 0.0 to I-5 PM 22.1 in November 2021, with the final report issued in April 2022. The audit identified major safety concerns within the Salt Creek Canyon segment PM 10.4 to 11.8, which experienced 23 collisions, including 4 fatalities, 2 serious injuries, and 7 minor injuries between January 1, 2025, and December 31, 2019. These findings were the primary reason for initiating this safety project.
The Actual Fatal Collisions Rate and Fatal plus Injury Collison Rate are higher than the Average Fatal Collision Rate and the Average Fatal plus Injury Collision Rate for other similar State facilities. The remainder for the corridor had undesirable conditions identified, some of which are being addressed via this project.
Cost Estimate:
The project is programmed in the 2024 State Highway Operation and Protection Program (SHOPP) and is funded under the 20.XX.201.010 Safety Improvements Program.
| Support Cost | $12,080,000 |
| Capital Cost | $34,540,000 |
| Total Project Cost | $46,620,000 |
Schedule:
| Draft Environmental Documents | April 2027 |
| Project Approval & Environmental Document | November 2027 |
| Design Completed |
February 2029 |
| Advertise Project | April 2029 |
| Begin Construction | June 2029 |
| Complete Construction | February 2030 |
Project Contacts:
Mary Fesliyan, Project Manager, (530) 821-8265; Mary.Fesliyan@dot.ca.gov
Megan Reese, Public Information Officer, (530) 682-6145 megan.reese@dot.ca.gov