SR37/Fairgrounds Dr. Interchange, Vallejo: Temp Closure & Detour on NB Fairgrounds, July 7

June 30, 2026

Date: 30 June 2026
Agency: Solano Transportation Authority, Caltrans District 4-Bay Area
Contact:  Sean Person, Contact:  Sabrina Martinez
Phone: (707) 399-3217, Phone: (510) 934-5257

State Route 37 (SR 37)/Fairgrounds Drive Interchange in Vallejo:
Watch for Temporary Closure and Detour on Northbound Fairgrounds
On Tuesday, July 7

SOLANO COUNTY  – The Solano Transportation Authority (STA), in close coordination with its transportation partner, the California Department of Transportation (Caltrans), is in the process of completing construction work on the new State Route 37 (SR 37)/Fairgrounds Drive Diverging Diamond Interchange (DDI) project in Vallejo. This is the first-ever DDI constructed in the Bay Area and only the second constructed on a major highway in California. The DDI was implemented to enhance safety and improve bicycle and pedestrian access in the area.

What to Expect:
The new DDI opened to traffic on Saturday, May 16, and final construction is slated to for completion soon. A temporary roadway closure and detour are planned, as follows:

• A temporary traffic closure of northbound Fairgrounds Drive is scheduled for Tuesday, July 7, from 5 a.m. to 1 p.m. Southbound Fairgrounds Drive and all other SR 37 ramps will remain open.
• Northbound Fairgrounds Drive will be closed between Sage Street and SR 37. Northbound traffic will be detoured right onto Sage Street, left onto Gateway Drive, and back to Fairgrounds Drive.
• Drivers traveling northbound on Fairgrounds Drive who wish to access either direction of SR 37 should follow the posted detour signs to reach the freeway on ramps from southbound Fairgrounds Drive.

Please follow on-site signage for detours and see the embedded map for additional closure information.

We appreciate the public’s cooperation and patience as important work on this important project continues! Motorists should drive with caution in construction zones, slow down for worker safety and expect travel delays. All work is weather dependent.

Diverging Diamonds are Safer and Easier to Access
Navigating the DDI is easy, just follow the road! Watch the informational video available on the STA website or at the link below for more information.

To learn about how to use the DDI, please watch our informational YouTube video at https://youtu.be/L7QOoovsVuU?si=AOsSTF2hREcpQwhA.

For general questions, please email our project team at: SR37-FairgroundsPIO@portal3.pbid.com.

For more information about the project, please visit https://sta.ca.gov/project/redwood-parkway-fairgrounds-dr-improvement-project/

For media inquires, please view the project media bar at https://dot.ca.gov/caltrans-near-me/district-4/d4-projects/d4-37-corridor-projects/37-diverging-diamond-interchange-media-resources

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