Napa County, CA Parking Rules: Commercial Vehicle Restrictions (2026)

California Vehicle Code Section 22507.5 authorizes local agencies to prohibit or restrict the parking of commercial vehicles on residential streets between 2:00 a.m. and 6:00 a.m. (or 10:00 p.m. and 6:00 a.m. with additional findings), provided proper signage is posted. Napa County and the cities within it have used this authority to restrict commercial-vehicle parking on residential streets, with enforcement by the Napa County Sheriff or municipal police as applicable. 'Commercial vehicle' is defined in Cal. Veh. Code Section 260 to include vehicles used or maintained for the transportation of property for hire or profit or designed primarily for transporting property; pickup trucks and other dual-use vehicles generally are not 'commercial' unless registered as such. On private property, Napa County Code Title 18 (Zoning) controls the parking and storage of commercial vehicles by use. In residential zones (RC, RS, RM, RR), the typical rule is that one commercial vehicle used by the resident in their employment may be parked at the residence (often with a size cap such as 10,000 pounds gross vehicle weight or 25 feet in length), but commercial vehicle fleets, trucking yards, or contractor staging are not permitted accessory uses and would require a use permit. In agricultural zones (AP, AW), parking of agricultural equipment - tractors, harvesters, gondola trucks, sprayers, vineyard ATVs - is a permitted accessory use to bona fide agricultural operations and is not treated as 'commercial' for parking purposes. Wineries and wine-related businesses operate under separate use permits that authorize commercial truck traffic associated with winery operations. Commercial vehicles must comply with California Vehicle Code requirements for licensing (often a commercial driver's license), weight limits on local roads, and the Federal Motor Carrier Safety Regulations where applicable. Trucks over 10,000 pounds may be restricted to designated truck routes; bypass routes around Yountville, St. Helena, and Calistoga have historically been points of contention given Hwy 29 truck traffic and downtown character. Truck idling restrictions under California Code of Regulations Title 13 Section 2485 (the heavy-duty diesel vehicle idling rule) apply to commercial vehicles statewide - a five-minute limit with exceptions.