Author: Neil Quintanilla

Date: January 20, 2026
Agency: 4 – Oakland
Contact: Sean Person, Geoffrey Johnson
Phone:  (707) 399-3217, (510) 421-7348

State Route 37/SR-37- Fairgrounds Drive Interchange- Vallejo
Solano Transportation Authority and Caltrans Begin the
Next Phase of Construction
Expect Delays on Fairgrounds Drive; See Map with Alternate Routes!

SOLANO COUNTY  – The Solano Transportation Authority (STA), in close coordination with its transportation partner, the California Department of Transportation (Caltrans), is continuing construction work on the new State Route 37 (SR 37)/Fairgrounds Drive Interchange Project in Vallejo. The interchange improvement project will enhance motorist safety and improve bicycle and pedestrian access with construction of a new divergent diamond interchange. This is the first-ever divergent diamond interchange (DDI) constructed in the Bay Area and only the second-ever constructed on a major highway in California.

What to Expect During Initial Construction Work
Construction at SR 37 and Fairgrounds Drive started construction in April 2025. The site is near the Six Flags Discovery Kingdom Theme Park and the Solano County Fairgrounds. In May traffic in both directions were shifted to the west side of SR 37 and a temporary pedestrian walkway was constructed. Now, STA and Caltrans are moving forward with work to reconstruct the existing Fairgrounds Dr and widen the roadway to accommodate the upcoming Diverging Diamond Interchange.

The following construction-related activities are slated for Monday – Friday during the weeks of January 26, 2026, and February 2, 2026.

Community members and motorists are advised to expect delays and are encouraged to use alternate routes during this time. (Please see map)

• Contractor to reduce northbound Fairgrounds Dr. from SR37 to Gateway Dr. down to one lane, day and night

• During this period, weather-permitting, Fairgrounds Drive will be restriped utilizing single lane closures during daytime hours, 7:00am to 4:00pm.

Motorists should drive with caution in construction zones and expect travel delays. All work is weather dependent.

We appreciate the community’s and motorists’ cooperation and patience as important work to improve the safety and accessibility of this important project continues!

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

For more information about the project and to view a video explaining the DDI design, please visit https://sta.ca.gov/project/redwood-parkway-fairgrounds-dr-improvement-project/.

 

 

Date: January 15, 2026
Agency: 4 – Oakland
Contact:  Sabrina Martinez
Phone:  (510) 934-5257
Email:  sabrina.martinez@dot.ca.gov

 

One Way Traffic Control on Miner Slough Bridge (PM 12.1)

Schedule: From 7 a.m. to 4 p.m.

 

SOLANO COUNTY  – Caltrans will start repair work to the deck of Minor Slough Bridge, which includes a repaving of the deck.

There will be daytime lane closures with one way traffic control from the entrance of Holland Rd to the other end of the bridge on Ryer Rd. Work will be conducted from 7 a.m. to 4 p.m. All work is dependent on weather.

Large trucks are advised to attempt to make tight turns and use cation when approaching the Miner Slough Bridge for your safety and the safety of people on the road.

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

For real-time traffic, click on Caltrans QuickMap: http://quickmap.dot.ca.gov/

Date: January 08, 2026
Agency: 4 – Oakland
Contact:  Sabrina Martinez
Phone:  (510) 934-5257
Email:  sabrina.martinez@dot.ca.gov

 

Nighttime Single Lane Closure Scheduled on State Route 29 (SR-29) at or near Redwood Street for Pavement Rehabilitation Project in Vallejo

Schedule: Lane closure scheduled from 4 p.m to 6 a.m. on Sunday and 9 p.m. to 6 a.m. the next morning for Monday through Thursday

SOLANO COUNTY  – Caltrans is continuing its pavement rehabilitation and Complete Street work on State Route 29 (SR-29), also known as Sonoma Boulevard, in January. Electrical-boring operations will be conducted in the areas of Redwood Street and SR-29.

Lane closures are scheduled from Sunday, Jan. 11 to Thursday, Jan. 15. With Sunday from 4 p.m. to 6 a.m. and Monday through Thursday from 4 p.m. to 11 a.m. the next morning. One lane in each direction will remain open to traffic at all times.

All work is dependent on weather.

For more information, see this site: https://dot.ca.gov/caltrans-near-me/district-4/d4-projects/d4-sr29-vallejo

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

Date: December 12, 2025
District: 4 – Oakland
Contact:  Sabrina Martinez
Phone:  (510) 934-5257
Email: sabrina.martinez@dot.ca.gov

Daytime Single Lane Closure on State Route-29 from Curtola Parkway to
Valley Vista Ave.(PM 1.92 /3.49)

Schedule: Lane Closure from 9 AM to 4 PM

SOLANO COUNTY  – Caltrans is continuing its pavement rehabilitation and complete street work on State Route 29, also known as Sonoma Blvd. The coming weeks will have multiple locations working on the deconstruction and repaving of various driveways and curb ramps.

There will be daytime closures for the deconstruction and repaving of the various driveways, approaches and curb ramps along State Route 29. Work will be conducted on both Southbound and Northbound sides of State Route-29 (Sonoma Blvd) from Curtola Parkway Drive to Valley Vista Ave. Starting 12/15/2025 to 01/02/2026 there will be intermittent single lane closures (depending on where the work occurs) one city street will remain open in the direction of travel during the day from 9 am to 4 pm. All work is dependent on weather.

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

For real-time traffic, click on Caltrans QuickMap: http://quickmap.dot.ca.gov/

Date: November 24, 2025
Agency: Solano Transportation Authority, Caltrans District 4-Bay Area
Contact:  Contact: Sean Person, Geoffrey Johnson
Phone:  (707) 399-3217, (510) 421-7348

State Route 37/SR-37- Fairgrounds Drive Interchange- Vallejo
Construction Shifts into Gear- December 2025
Watch for Traffic Lane Shifts/Overnight Ramp Closures

SOLANO COUNTY  – The Solano Transportation Authority (STA), in close coordination with its transportation partner, the California Department of Transportation (Caltrans), has started construction work on the new State Route 37 (SR 37)/Fairgrounds Drive Interchange Project in Vallejo. The interchange improvement project will enhance motorist safety and improve bicycle and pedestrian access with construction of a new divergent diamond interchange. This is the first-ever divergent diamond interchange (DDI) constructed in the Bay Area and only the second-ever constructed on a major highway in California.

What to Expect During Initial Construction Work
Construction at SR 37 and Fairgrounds Drive started construction in April 2025. The site is near the Six Flags Discovery Kingdom Theme Park and the Solano County Fairgrounds. In May traffic in both directions was shifted to the west side of SR 37 and a temporary pedestrian walkway was constructed. Beginning mid-December, traffic will be shifted to the east side of SR 37, under the freeway.

Weather permitting, the following construction-related activities are scheduled to happen in mid-December, 2025.

• Motorists on Fairgrounds Drive at SR 37 should watch for temporary traffic lane shifts and follow all on-site signage.
• The eastbound off-ramp at SR 37/Fairgrounds Drive will be closed overnight with detours. Closures are scheduled from 10:00 PM until 6:00 AM.
• The eastbound on-ramp from Fairgrounds Drive to SR 37 will be closed nightly from 10:00 PM – 5:00 AM.
• The westbound off ramp from SR 37 to Fairgrounds Drive will be closed nightly from 11:00 PM – 5:00 AM.
• The westbound on-ramp from Fairgrounds Drive to SR 37 will be closed nightly from 8:00 PM – 6:00 AM.

Motorists should drive with caution in construction zones and expect travel delays. All work is weather dependent.

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

For more information about the project and to view a video explaining the DDI design, please visit https://sta.ca.gov/project/redwood-parkway-fairgrounds-dr-improvement-project/.

STA and Caltrans thank the motoring public for its patience and understanding as we work to improve and maintain our state’s highways.

Date: November 13, 2025
District: District 3 – Marysville
Sergio Aceves, District 3 Director
Contact:  Dennis Keaton dennis.keaton@dot.ca.gov
Phone:  (916) 825-5252

UPDATE – 55 Hour Closure Friday, November 14 through 4 a.m. Monday, November 17 for the Rio Vista Bridge is Postponed due to Weather

RIO VISTA – Caltrans is advising motorists that this weekend’s 55-hour closure for repair work on the ongoing $27.2 million State Route 12 (SR 12) Rio Vista Bridge (Helen Madere Memorial Bridge) Rehabilitation Project has been postponed due to weather. The bridge will remain open to motorists.

A rescheduled weekend has not yet been determined.

All construction schedules are subject to change due to weather conditions, equipment and/or material availability, or other unexpected events.

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 X @CaltransDist3 and on Facebook at CaltransDistrict3. For real-time traffic, click on Caltrans’ QuickMap or download the QuickMap app from the App Store or Google Play.

For real-time traffic, click on Caltrans QuickMap: http://quickmap.dot.ca.gov/

Date: October 29, 2025
District: 4
Contact:  Sabrina Martinez
Phone:  (510) 934-5257
Email: sabrina.martinez@dot.ca.gov

Daytime Single Lane Closure on State Route-29 between Ryder St and Arkansas St. (PM 1.45 and 3.02)

Schedule: Lane Closure from 9 AM to 3 PM

 

SOLANO COUNTY  – Caltrans is continuing to work on installation of new electrical equipment to improve pedestrian safety at unsignalized crosswalks around Solano County. This includes new ADA curb ramps and restriping the cross walks around the intersection.

Work will continue on Ryder St. and Arkansas St. along SR-29. Installation of foundations for new electrical poles will require a lane closure. Starting Monday, November 3 to November 14 a single lane will be closed with one city street open in the direction of travel during the day from 9 am to 3 pm. All work is dependent on weather.

Pedestrians are directed to utilize the crosswalk on the other side of the road via signage barricades on the sidewalk.

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

For real-time traffic, click on Caltrans QuickMap: http://quickmap.dot.ca.gov/