SR128 Conn Creek Bridge Replacement Project

SR 128 Conn Creek Bridge Replacement Project Map

Project Overview

Caltrans will replace the Conn Creek Bridge on State Route 128 (SR-128) in Napa County near Saint Helena.  The bridge which is located on Silverado Trail will be replaced with a wider bridge to accommodate trucks turning right from eastbound SR-128 (Conn Creek Road) onto southbound Silverado Trail.

Project construction limits on Silverado Trail are from approximately 500’ north and south of Conn Creek Road.  Construction on Conn Creek Road extends to approximately 150’ west of Silverado Trail.

Please note: SR-128, travels east-west from Conn Creek Road to Sage Canyon Road, and traverses on Silverado Trail for approximately 400’, only; Silverado Trail is otherwise a County of Napa roadway.

Traffic Delays & Handling

Traffic delays should be expected during construction of the bridge due to construction staging.  It is required to close the shoulders. There will be occasional short-term (5-10 minutes) lane or highway closures and a reduction to one lane for use by traffic in both directions of travel during off peak hours.

One lane in each direction of travel will be provided at all times other than the aforementioned occasional closures.

Only one lane will be provided in the westbound SR-128 direction to share for through traffic traveling north on Silverado Trail and traffic turning left to westbound Conn Creek Road.  

A separate left turning lane in the eastbound SR 128 direction, from southbound Silverado Trail to Sage Canyon Road will be provided in addition to the through lane for traffic continuing south on Silverado Trail.

Bicycle traffic will be sharing the main traffic lanes within the project limits.

Construction Staging

Currently, the southern portion of the new bridge, constructed in 2019 is being used to pass traffic through the project site, as the northern portion of the new bridge is constructed.

In 2019, Caltrans removed the southern portion of the old bridge and constructed the southern portion of the new bridge.

Please note: Caltrans contractor may propose to construct the bridge using different staging scheme(s).

Project Timeline

Construction work has begun.  The new bridge is expected to be completed by Winter 2020.

Contact Information:

Pedro Quintana
Caltrans Bay Area Public Information Officer
Phone: (510) 286-5620