NEV 20 Omega Curves Project

Project Description

This project proposes to improve two non-contiguous segments of the alignment of State Route (SR) 20 in Nevada County between post miles (PM) 29.7-30.9 (White Cloud) and 36.8-39.8 (Lowell Hill) by modifying the existing horizontal and vertical curves of the roadway and adding turnouts. This project will update the roadway to current standards by increasing the curve radii, widening shoulders to 8 feet, adding turnouts for both directions, and improving the vertical profile grade. Additionally, the project will widen an existing turnout to standard width on SR-20 from PM 36.8 to 37.0.



The purpose of this project is to improve safety and reduce the number and severity of collisions by increasing the curve radii, widening shoulders, adding turnouts, improving the vertical profile, and improving the clear recovery zone.


These two sections of roadway experienced a total of 39 collisions in a recent 3-year period (January 1, 2015 to December 31, 2017), including 19 collisions involving injuries. The resulting total accident rate is higher than the statewide average for a similar type of facility. In addition, this section of the existing two-lane conventional highway facility has no room to pass. Slow-moving traffic has the potential to delay traffic flow leading to unsafe passing movements.



This project is funded by the 2020 State Highway Operation and Protection Program (SHOPP) under the Operational Improvement program. 


Cost Estimate

Support Cost: $15,689,000
Capital Cost: $39,630,000
Total Project Cost: $55,319,000



Project Approval & Environmental Document: May 2020
Design Completed: April 2021
Advertise Project: August 2021
Begin Construction: October 2021
Complete Construction: November 2023


Project Contacts

Sam Vandell, Project Manager
(530) 741-4593


Raquel Borrayo, Public Information Officer