Public WorksRoads




Welcome to the Napa County Roads Division. We are committed to maintaining and preserving the Napa County road system so that it is safe, reliable and accessible for all users.
The Roads division is responsible for maintaining approximately 450 miles of public roads, 79 bridges and 50 major drainage structures within the unincorporated area of the County. The division is active in other road-related safety efforts such as vegetation management and maintenance of structure, drainage facilities, guardrails, traffic signs, signals and pavement markings.
We invite you to visit our links page for useful road and safety links.


Special Events on County Roads

More information about these events, which include marathons, bicycling events, triathlons and more -- including application information and how to submit concerns to County staff.


Major Road Construction in Napa County 2017-2020 


New Development - Traffic Impacts


Traffic Impact Studies

Requirements for preparation of traffic impact studies

Evaluation of cumulative impacts

Left Turn Lane Warrant Graph


Traffic Mitigation Fees -- Napa Valley Business Park

All new development, or improvements to existing development that will generate additional traffic, in the Napa Valley Business Park (area surrounding Napa County Airport) are subject to a Traffic Mitigation Fee


Call Before You Dig

For projects which include underground excavation, information about Underground Service Alert (USA) requirements.

Partnering for Safety


The County has partnered with Cal Fire and various fire safe councils to remove and reduce the fire fuel load along our roadways.  County crews provide traffic control, equipment and some tools.  Cal Fire supplies an inmate crew with tools, and the Fire Safe Councils handle public outreach, coordination with landowners and identifying priority areas.


Removing and reducing vegetation along roadsides improves both fire safety and traffic safety, and is the biggest part of the Roads budget.  This partnership helps get much more work done for much less cost.


Videographer/drone operator Evan Kilkus filmed this partnership work in progress along Lake Berryessa Road in March, 2015, and has made this video footage available to the County.  The music has been provided courtesy of local musician Bill Scholer.