State Route 29/California Roundabouts

Project Description/Background

The State Route 29 (SR 29) Northbound First Street Ramps and California Boulevard Roundabouts Project (Project) involves the reconfiguration and construction of three modern roundabouts at First Street and California Boulevard, Second Street and California Boulevard, and SR 29 northbound on and off ramps at First Street.

The purpose of the Project is to relieve existing and future traffic congestion, improve traffic safety and traffic operations, and minimize queues and delay for all three intersections within the Project limits.  Furthermore, the Project includes bicycle and pedestrian facilities to encourage multi-modal forms of transportation.

The Project will accommodate bicycle and pedestrian traffic through a combination of sidewalks, shared use paths and bicycle lanes. Other features of the project include street lighting, landscaping, irrigation and storm drain systems, new side mounted and overhead signs to assist in navigating the roundabouts, the construction of retaining walls, and re-grading to accommodate street design grades and cross-slopes.

The Project will also increase mobility into and out of Downtown Napa through the reversal of First Street and Second Street between California Boulevard and Jefferson Street. Currently, First and Second Streets, between California Boulevard and Jefferson Street operate as a one-way couplet (with east and west-bound traffic separated onto two two-lane streets, rather than allowing two-way traffic on both streets). As part of the Project these streets will be reversed: First Street would become east-bound only, while Second Street would become west bound only, each from the California Boulevard roundabouts to Jefferson Street.

CA Roundabouts Concept

Construction Activities

November 22, 2019

Our first roundabout is now open! Remember, drive with caution and be safe on the roadways. Slow and steady wins the race.
Now, up next – crews will continue work on the second and third roundabouts, as well as all the other associated improvements such as landscaping, curbs, bike lanes and more. By Christmas, we should see the next roundabout up and running! In the meantime, you can check out this video to see a simulation of how all three roundabouts will work together when completed in early 2020.

Please remember to drive safely and take your time – we appreciate everyone’s patience!

November 15, 2019

The first of the three roundabouts, as well as the northbound SR-29 offramp, is slated to open on Thursday, November 21. Motorists will be able to use this first roundabout to get on and off the freeway at First Street, as well as to navigate between First Street and California Boulevard.

California Boulevard will remain closed between Clay Street and Second Street, and there will still be detours in place as construction crews continue working on the remaining two roundabouts.

This is exciting news, as this first roundabout is opening far ahead of schedule. What was expected to be at least an 18-month job has reduced considerably, with the next roundabout possibly in use just before Christmas and the third begin to carry traffic in early 2020 depending on weather.

Additional information will be shared on social media at the beginning of next week on how to travel through a roundabout whether in a car, on a bike or on foot.

Please remember to drive safely and take your time – we appreciate everyone’s patience!

October 10, 2019

As you can see from the cool photos to the right, a lot of progress has been made on the project. The first of the three roundabouts is beginning to emerge! We are excited to say that the first of the three roundabouts will be open before Thanksgiving, and the second will be open by Christmas! The project contractor, O.C. Jones, took these great photos and has been working diligently to keep this work moving as quickly as possible. We realize the inconvenience this much construction creates, but appreciate our community’s patience as we move closer to finished roundabouts even more quickly than anticipated.

Detours will remain in place, along with previously announced detours currently in place due to the construction. Motorists are encouraged to use alternative routes and allow more time to get to their destinations. Delays are expected in the construction area and drivers should exercise caution.

For more information from Caltrans, visit the Napa Roundabout Webpage at

Work on the three roundabouts is expected to conclude in 2020.

Project Simulation

The design consultant for the Project, Omni-Means (A GHD Company), prepared a traffic simulation to illustrate how the Project will operate after completion.


Comments and questions may be directed to the Engineering Division email address: