Navigating California DMV Rules for Cannabis and Driving in 2025
In the 1960's Jefferson Airplane lead singer Grace Slick warned against methamphetamine telling her audiences “Speed Kills”. On the other hand, California has been at the forefront of cannabis legalization since - well its seems like forever. Despite federal law, in California recreational use became legal for adults 21 and older in 2018 (via Proposition 64). California even has its own Cannabis Department.
But when it comes to hitting the road, the rules are crystal clear: cannabis in any amount that affects driving is unlawful. The California Department of Motor Vehicles (DMV) treats cannabis impairment similarly to alcohol under DUI laws, with strict prohibitions on use, possession, and open containers in vehicles.
Whether you're a recreational user or medical patient, here's a breakdown of the key DMV rules based on the latest California Driver's Handbook (Section on Alcohol and Drugs), Vehicle Code §23222(b), and related statutes as of late 2025. No major changes to these core rules occurred in 2025.
Driving Under the Influence of Cannabis (DUI)
It's illegal to drive while impaired by any drug, including cannabis, that affects your ability to operate a vehicle safely. This falls under Vehicle Code §23152(f) (driving under the influence of drugs) or §23152(g) (combined with alcohol).
As with all drugs except alcohol, there is no specific THC limit: Unlike alcohol's 0.08% BAC threshold, California has no "per se" limit for THC (the primary psychoactive compound in cannabis).
What Must Prosecutors Prove for a Cannabis DUI?
Prosecutors must prove actual impairment through observed behavior, field sobriety tests, or Drug Recognition Expert (DRE) evaluations. That is the same rule as for prescription drugs.
Impairment can come from smoking, edibles, vaping, or any cannabis product. How you ingested the marijuana is irrelevant to the impairment assessment. Combining cannabis with alcohol or other drugs in some cases (but not all) worsens impairment but the issue is not what drugs you took as much as whether you are impaired. There is a CHP commercial that reminds people “If you’re buzzed, you’re impaired”. As lawyers we then aske the question - “How Impaired?”. All (relevant to this discussion) drugs alter your perceptions and reactions but what level of drug effects translates into driving impairment. It is much more complex than “If you’re buzzed, you’re impaired”.
The marijuana penalties are the same as alcohol DUI: fines, license suspension, DUI classes and possible jail time. As far as we know there is no ignition interlock devices that detect marijuana. California's "open container" laws extend to cannabis under Vehicle Code §23222(b):
You cannot drive with an open container of cannabis or cannabis products (e.g., broken seal on a dispensary package, partially used edibles, or loose flower not in a sealed container).
"Open" includes any receptacle with a broken seal, partially removed contents, or loose cannabis flower (buds, leaves) not in a container. Open or unsealed items must be stored in the trunk or an area inaccessible to the driver/passengers (not glove box, center console, or on your person).
Fully sealed, unopened containers (or resealed/closed ones) are allowed in the passenger compartment. We can certainly argue about what constitutes an “open container” and the courts seem to be “all over the place” in defining an “open container” of marijuana. We advise our clients to be safe and treat marijuana like a gun. Keep in your trunk. We have argued that medical marijuana can be kept in a pill container just like any medicine but again, rather than pay a lawyer to make new law - using the trunk is a safe bet.
There are many other issues that are relevant in cannabis cases. Officers may use roadside saliva tests or call DREs for cannabis-specific signs of impairment. However the reliability of these tests and their accuracy in determining when marijuana was consumed are often litigated successfully by DUI lawyers.
Call A Criminal Law Expert
If you are arrested for any type of DUI case whether it involves alcohol, marijuana or a combination of substances, call Criminal Defense Lawyer Daniel Horowitz at (925) 283-1863.
