Traffic Information is updated weekly to describe impacts from construction in the City of Napa and surrounding areas. For general Bay Area traffic information, visit and for Caltrans highway information visit See current CHP activity at

Here's the latest news on traffic and construction impacts in and around the City of Napa.

Updated Dec 12, 2013

1. Caltrans, the Solano Transportation Authority (STA), and the Napa County Transportation and Planning Agency (NCTPA) are underway with work to widen Highway 12 through Jameson Canyon in Napa and Solano Counties. Drivers should anticipate ongoing construction activity. Changeable message signs will alert drivers to any lane closures or detours that may be needed, and information will be posted here as the work progresses. When closures occur, Highway 37 the recommended detour route between Highway 29 and I80. Additional project information is now posted on Caltrans’ new Highway 12-Jameson Canyon webpage at:

2. A major project to underground utilities and make improvements to Highway 29 is underway in the St. Helena area, from Mee Lane (south of the city) to Charter Oak Avenue (in the city). PG&E will build a trench, place the overhead utility and services lines underground, and remove the utility poles along the highway. Caltrans will follow with a project to build a continuous two-way left turn lane, and an overall safer highway for residents, visitors and bicyclists, with standard-width shoulders and a bicycle ‘fly around’ at the Whitehall Lane railroad crossing. Contractors are committed to keeping both lanes open whenever possible during construction. Private and public entities and the utilities are working together in a coordinated effort to mitigate the short-term impacts of construction. Detaile information on the project can be found at

3. Through January 2014, drivers will encounter construction traffic along both Airport Boulevard and Devlin Road while crews work to extend a segment of Devlin Road from Airport Boulevard south toward Aviation Way. The work will take place near the intersection of Airport Boulevard and Devlin Road in the Airport area of the County. Construction will occur between the hours of 7:00 a.m. and 5:00 p.m., Monday through Friday. Construction equipment and trucks will be moving in and out of the area during work hours to complete the construction project. Short term, single-lane closures along Airport Boulevard may be necessary to make necessary modifications to the existing traffic signal and alterations to the existing pavement. No long-term road closures are planned.


Drive safely while we’re building a safer Napa.