Napa County Quarterly Caltrans Update

Safety first – Cultivate excellence – Enhance and connect the multimodal transportation network – Strengthen stewardship and drive efficiency – Lead climate action – Advance equity and livability in all communities


Welcome to the second Napa County Caltrans E-Newsletter!

Our goal is to provide you with the status, resources, content, data and links to various information related to Caltrans work in Napa County.

Napa County is nestled in one of the most picturesque settings in Northern California known for its rolling hills, vast wineries, spectacular views, and the BottleRock music festival.


Visit our project website for additional updates.

For project questions & to sign up for our weekly newsletter, please contact us at EMAIL.

Project Highlight: Soscol Junction Roundabout Project

The State Route 29/ State Route 221 (SR- 29/SR-221) Soscol Junction Roundabout Project is currently in construction in phase 3 of 6 total phases. The Project is 63% complete with completion scheduled for Fall 2024.

Northbound SR-29 traffic has been shifted to the new alignment traveling over the new bridge overcrossing the future SR-221 alignment.

Map showing the location of the Soscol Junction interchange where State Route 29, State Route 221 and Soscol Ferry Road intersect in south Napa County.

In mid April 2024, the Southbound traffic lanes of SR-29 were aligned to join the Northbound traffic SR-29 lanes as part of the roundabout construction.

When completed, this project will replace the signalized intersection of SR-29, SR- 221 and Soscol Ferry Road with an interchange comprised of a new overcrossing carrying SR-29 traffic over SR-221/Soscol Ferry Road and two multi-lane roundabouts on either side of the new overcrossing.

Photograph of one of the new ramps that has been constructed as part of the Soscol Junction project.New on- and off-ramps will also be constructed to provide the connection of SR-221 and Soscol Ferry Road traffic traveling through the two roundabouts to SR-29. This configuration will smooth out traffic flow, reduce congestion and enhance bicycle and pedestrian connectivity.

In partnership with the Napa Valley Transportation Authority (NVTA), construction continues on the new southbound lanes of SR-29 and the two roundabouts of SR-221/Soscol Ferry Road traffic with completion scheduled as early as Fall 2024.

The project also includes a new 1,200-foot Class I bicycle and pedestrian path. Eventually, the path will connect to the Napa Valley Vine Trail - a 47-mile multi-use path that will stretch from Calistoga to the Vallejo ferry terminal.

In addition to funding from the Road Repair and Accountability Act of 2017 (SB-1) $19.3 million in state and regional funds and $3.7 million in local funds will be used in the total approximate project cost of $ 54 million for the Soscol Junction Project.

Here is a sneak peek video visualization of what the new roundabouts will look like when construction is completed!

Soscol Junction Animation

Overview of Completed Project

An overhead rendering of what is being built at Soscol Junction which features an interchange comprised of a new overcrossing carrying SR-29 traffic over SR-221/Soscol Ferry Road and two multi-lane roundabouts on either side of the new overcrossing. There is an insert image showing a close-up view of the two roundabouts.

State Route 37-Pavement Repairs Now and Plans for The Future

Caltrans is always working to improve the driving experience for motorists on State Route 37. (SR-37), which connects to Napa County and is a major route across the North Bay.  

Trucks and a roller vehicle are on State Route 37 as part of a Caltrans paving project.Recently, Caltrans completed four weekends of 55-hour closures to repave both travel directions of SR-37 between Solano and Sonoma counties. The paving work was needed due to high traffic use which caused wear and tear on the roadway pavement. 

Currently, the East-West highway is one of the most heavily travelled in Solano and Sonoma County and is a major connector route to Napa County.

In addition to routine maintenance and major pavement repairs, SR-37 needs new infrastructure to handle the high volume of traffic and also the low-level marsh that is close to the roadway. 

Caltrans is working with multiple transportation agencies in the North Bay on short term and long-term projects focusing on SR-37 and keeping the vital link safe and accessible for all motorists. 

For more information on the future plans for SR-37, go to our Resilient 37 project website.

Cones are used to close westbound State Route 37 in Vallejo as part of a Caltrans paving project.


SR-29 Intersection Improvements at Rutherford Road and Oakville Cross Road in Napa’s Up Valley 

Caltrans as an oversight agency in close cooperation with the Napa Valley Transportation Authority (NVTA) and the Metropolitan Transportation Commission (MTC) are currently working together on multi-modal safety and operational improvements on State Route 29 (SR-29) between Oakville Road and Rutherford Road. (State Route 128). 

Rendering of the proposed traffic signal that will be constructed at Rutherford Road and State Route 29.

SR-29 is the primary route that connects Napa to nearby Lake and Solano counties. It is a critical route used for evacuation during wildfires and other emergencies.

Rendering of a car entering the proposed roundabout at the intersection of State Route 29 and Oakville Road.

The project will improve safety for the intersection at these two key locations.

Pending Caltrans approval, a traffic signal will be constructed at Rutherford Road in Winter 2025. 

For Oakville Road, a roundabout is to be completed. 

Caltrans is currently reviewing the plans and will make a determination whether to move forward with the plans in the next year or two. Watch for our next Caltrans Napa Newsletter for updates! 

The Napa County newsletter will be distributed on a quarterly schedule.

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Napa County Public Information Officer

Ryan Leong 

General Information
(510) 286-4444

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