California Motor Vehicle Code 23222
Open Containers While Driving
Working alongside code 23220, vehicle code 23222 prohibits any driver from operating a vehicle with an open container of alcohol. An open container is considered any bottle, can, or receptacle containing an alcoholic beverage that has a broken seal or the contents of which have been even partially removed.
Drivers must take specific care when transporting open containers, or alcoholic containers where the seal has been broken, even if the driver is not drinking from the container while driving. Keeping containers of this variety out of arm's reach and in the trunk is the best option, though a police officer may be suspicious of any open container in the the vehicle.
This law is extended to marijuana. Any driver found to be operating a vehicle with less than one avoirdupois ounce of marijuana in his possession, will be punished with an infraction and fine. Larger amounts of marijuana, or larger concentrations of cannabis, will be punished with more serious consequences.