State Route 20 Temporary Closure Begins Next Week


California State Route 20

District: District 3 - Marysville
Amarjeet S. Benipal, District Director                        
Contact: Jeremy Linder
Phone: (530) 701-5209


Nevada County– Caltrans is reminding motorists State Route 20 (SR-20) will be closed 17 miles east of Nevada City in Nevada County starting next week, as construction continues work on the Omega Curves Project.

The Lowell Hill segment will be closed, between the Omega Overlook and Bear Valley, Sunday, September 24 at 7 p.m. through Sunday, October 1 at 7 p.m. The While Cloud segment will be closed, between the White Cloud U.S. Forest Service and Campground and Washington Road, Sunday, October 1 at 7 p.m. to Friday, October 6 at noon. 

The California Highway Patrol will be on site to enforce the closure with access for emergency vehicles only. In the event of an emergency CHP will communicate with crews on sight and take appropriate action.

Motorists looking to travel between Interstate 80 and Nevada City should use State Route 49 or State Route 174 as an alternate route. Large trucks are directed to only use State Route 49.

The schedule is subject to change or be delayed due to weather, availability of materials or other unexpected events.

During the closure, construction crews will perform grading and paving work to construct tie-in locations to divert the traveling public from the current roadway to the new alignment.

map of highway 80 state route 20 omega

The work is part of the $54.6 million Omega Curves project, which will improve safety and reduce collisions on SR-20 by realigning curves on two non-contiguous segments near White Cloud and Lowell Hill, widening shoulders, improving the highway’s sight distance, and adding designated left-turn lanes near Conservation Road and Washington Road. In addition, three turnouts will be added where slow-moving vehicles can allow motorists to safely pass, while also serving as traffic-enforcement locations for the CHP. 

map of route 20

Granite Construction, Inc. of Sacramento is the prime contractor for the Omega Curves safety project, which is expected to be completed this fall. For project updates, please visit

Caltrans District 3 is responsible for maintaining and operating 4,385 lane miles in 11 Sacramento Valley and Northern Sierra counties. Caltrans reminds motorists to “Be Work Zone Alert” and slow in construction zones for the safety of travelers and crews performing these improvements. 

The department will issue construction updates on @CaltransDist3 and on Facebook CaltransDistrict3. For real-time traffic, click on Caltrans’ QuickMap or download the QuickMap app from the App Store or Google Play.

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