Welcome to the Solano County Caltrans Newsletter!

The 18 mile stretch on I-80 running from Fairfield to Vacaville opened in December 16, 2025, as Express Lanes. Express Lanes help commuters get to where they want to go faster.

Express Lanes still offer HOV benefits for those who want to Carpool. Passengers need a FasTrak Transponder set to the appropriate number of passengers to receive the discount. 3+ ride for free and 2+ get half off. Lanes run from 5 am to 8 pm 7 days a week.

For more info visit: Solano I-80 Express Lanes Project

SR 37/Fairground Diverging Diamond Interchange Project

I n the background chugging along like the little engine that cold is the first of its kind in the Bay Area. The Solano Transportation Authority, along with Caltrans, is building the Diverging Diamond Interchange (DDI) in Vallejo to relieve congestion and make commute through this intersection more efficient.

What is a Diverging Diamond?

A DDI is a highway intersection that temporarily shifts traffic to the left side of the road to allow for free-flowing,, unprotected left turns onto highways. It increases capacity, reduces collision points by over 50%, and improves safety by eliminating the need to cross in front of oncoming traffic.

If you would like to see this in action head to this amazing video—Fairgrounds DDI Vallejo

It may look intimidating at first, but once you are in the interchange it is as easy to navigate as Dorthy and Toto navigated the yellow brick road.

This is the beginning of many improvement projects coming to State Route 37.

To read more about it head here, https://sta.ca.gov/project/redwood-parkway-fairgrounds-drimprovement-project/

And if you want extra credit read about SR-37- State Route 37 Corridor Project

State Route-29 Pavement Rehabilitation and Complete Street

State Route 29, also known as Sonoma Boulevard, in Vallejo is having a new year new me kind of year. Work has started with this highly anticipated project. Crews are currently working in Segment 2 and they have been updating alley ways and curb ramps for smoother transitions from the alley to the street. Also making the curbs in the area ADA compliant.

The paving will be the cherry on top, meaning the paving occurs closer to the end of the time line. In the interim Caltrans Maintenance has gone out and patched some of the major pot holes.

In addition to this project there is a secondary project, Enhanced Traffic Safety at Uncontrolled Intersections, that is working through out Solano. Currently working in Vallejo and on State Route-29. Work consists of installation of new electrical equipment to improve pedestrian safety at unsignalized crosswalks and includes new ADA curb ramps and restriping the cross walks additional location are on I– 80 and I-780 in Vallejo, Benicia, and Fairfield.

For more information on this project please go to our website - Caltrans State Route 29 Webpage

Expected to complete Late Fall 2026

Interstate Highway 80 Cordelia Truck Scales

August 15, 2025, ground breaking was held for the new truck scales near Fairfield on Westbound I-80. Shortly after construction began a lot of earth has been moved since then to make way for the future of highway safety and efficiency.

This project has stayed on schedule, but with spring around the corner bird nesting season is close behind. Caltrans is aware of ecological impacts that may occur with construction. A part of building a Cleaner California, Caltrans is trying to integrate ecosystem protection into transportation planning by making it a goal to minimize impacts to the environment or animal habitats. In the I-80 Cordelia project crews are on the look out for any birds that may nest in the tress along the I-80 Corridor. Some of the birds that like to nest in the area are Red-tailed Hawks, White-tailed Kites and the American Kestrels. If these birds decide to nest in the area of constructs crews will attempt to miti-gate impact to their nest, like putting a pause on construction until nesting season is over.

For more on this project please go to the following— Cordelia Truck Scales Improvement Project

The Solano County newsletter will be distributed on a regular schedule.