News

55-Hour Full Closure of SR37 Vallejo-Sonoma, Oct. 23, from 10PM to Oct. 26, 5AM

October 14, 2026

Date: October 12, 2026
Agency: 4 – Oakland
Contact:  Bart Ney
Phone:  (510) 715-7212
Email:  Bart.Ney@dot.ca.gov

 

55-Hour Full Closure of State Route 37 Between Vallejo and Sonoma Scheduled Friday, October 23, from 10:00 PM to Monday October 26, 5:00 AM

All work is weather dependent.

 

SOLANO, NAPA AND SONOMA COUNTIES  –

Caltrans District 4 will be implementing multiple closures on SR-37 in both Eastbound (EB) and Westbound (WB) directions as part of emergency preparedness for El Niño storm preparation. Crews are expediting work requiring full closures of the route

First, on Wednesday October 21st and Thursday October 22nd Caltrans will be closing SR-37 in the WB direction only from 7PM to 4AM the next day. Second, at 10 p.m. Friday, Oct. 23, until 5 a.m. Monday, Oct. 26, the Department will close both EB and WB Lanes on State Route 37 (SR-37) from Mare Island to Sears point in Solano/Napa County. Work will consist of median demolition and k-rail installation to shift both EB and WB traffic to the WB Lanes.

Once the shift is complete, crews will focus their efforts on the EB lanes to raise portions of the roadway by 3 feet to improve resiliency and address flooding concerns along this vital transportation corridor.

The 55 Hour closures will start Friday October 23, at 10:00 p.m. to the following Monday October 26, at 5:00 a.m.

Changeable Message Signs (CMS) have been deployed throughout the region to notify motorists of the upcoming closure and encourage travelers to plan ahead.

In addition, overnight secondary closures have been scheduled for Friday November 13 from 10:00 p.m. to 5:00 a.m., Sunday November 15. This work is to remove the temporary barrier installed on Westbound and shift traffic/install temporary barrier onto Eastbound.

Detours routes are as follows:

EB SR-37 DETOUR:
Motorists traveling eastbound on SR-37 will need to exit left onto northbound SR-121 in Sonoma; Make a right on SR-12/SR-12, 1(Carneros Hwy) and continue;Right on SR-12/SR-29; Enter left for the connector loop Off-ramp back to EB SR-37.

Please note that all work is weather dependent and additional weeknight work may need to be scheduled. Please Plan Ahead and stay tuned for more information to follow.

WB SR-37 DETOUR:
Motorists traveling Westbound on SR-37 will need to exit right onto northbound SR-29 in Napa, and follow SR 29 to WB SR 12 then to SB SR 121;

What Motorists Should Know

  • Westbound SR-37 will be closed nightly from 7 p.m. to 4 a.m. on Wednesday, Oct. 21, and Thursday, Oct. 22.
  • During 55 Hour Closure, SR-37 will be fully closed in both directions between Mare Island and Sears Point from;
  • Closure starts: Friday, Oct. 23, at 10 p.m.
  • Closure ends: Monday, Oct. 26, at 5 a.m.
  • Expect significant delays and increased travel times
  • Use alternate routes whenever possible
  • Follow posted detour signs and traffic control devices
  • All work is weather dependent

For 24/7 traffic updates, follow 511.org: https://twitter.com/511SFBay

For real-time traffic, download the QuickMap App available in your App store or click on Caltrans QuickMap: http://quickmap.dot.ca.gov/

Or follow Caltrans on
Instagram at: https://www.instagram.com/caltransdistrict4/




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