Can You Get a DUI for Driving While High in California?

Last Updated on July 2, 2025

While recreational marijuana may be legal in California, driving under the influence of cannabis is still a crime. While most people associate DUIs with alcohol use, California Vehicle Code 23152(f) (VC) allows people to be charged with this crime after driving under the influence of any controlled substance, including marijuana. Even if you have a valid medical marijuana prescription in California, you may be charged with a DUI if police believe the drug impacted your driving ability. Fortunately, you can fight marijuana DUI charges with the help of a top driving while high attorney like Peter M. Liss.

What Happens if an Officer Suspects You of Driving While High in California?

If police suspect you have been driving under the influence of drugs, they will typically request you to perform a field sobriety test. These highly subjective examinations are optional, and refusing will not be used against you. However, anything you do wrong after agreeing to take a field sobriety test can be used as evidence against you.

Whether or not you take the field sobriety test, if an officer believes you to be driving while high, they may request you to take a chemical test to confirm if you have been using marijuana or another drug. Under state law, you must submit to a chemical DUI test when asked to do so. These tests will provide the core of the evidence in the prosecution’s DUI case in California. Still, if a driver does not admit to being under the influence, it can be difficult to show whether or not a driver was high while driving.

While a blood test can provide a fair evaluation of how much cannabis someone used, these tests need to be performed within 1.4 hours of when the person used a drug, and police officers rarely can arrest a suspect and bring them in to get tested within this timeframe. Meanwhile, the effects of marijuana can last beyond the time frame these tests can account for, particularly if a person consumed an edible.

Currently, no breath or urine tests can accurately measure how much marijuana someone uses before driving.

Note that police are not legally required to administer a chemical test for drugs at all, but you have the right to request one.

What About Cheek Swabs?

Sometimes, officers may ask a driver believed to be intoxicated with marijuana or other drugs to take a cheek swab test. The SDPD uses a device called the Dräger 5000, which uses a cheek swab to test for drugs. It can produce results within 8 minutes. The Dräger 5000 is promoted as being able to determine if someone is under the influence of:

• marijuana
• methamphetamine
• benzodiazepines (such as Valium, Xanax, and Klonopin)
• cocaine
• opiates
• methadone
• ketamine

Unfortunately, the Dräger 5000 has not been determined to be accurate in estimating whether a person is currently under the influence of these drugs, so it cannot legally be used in place of a blood test. These mouth swab tests closely resemble field sobriety tests because they are 100 percent voluntary and only benefit the police officer by providing them with more evidence against you if you are charged with a DUI.

While the cheek swab test is voluntary, if you refuse it and police have grounds to suspect you are under the influence of drugs, they can arrest you. However, if the police lead you to believe that the test is mandatory or arrest you merely for refusing the test without other probable cause, a marijuana DUI lawyer may be able to have the charges against you dropped.

What is the California Marijuana Driving Limit?

There is no legal limit for cannabis consumption in California. Instead, it is simply illegal to drive while “under the influence” of the drug, meaning if it affects your ability to drive, you should not be behind the wheel. Simply put, if you feel there is any chance you could be high after using marijuana, you should not drive.

Unfortunately, the ambiguity of the law makes DUI charges complicated, as an officer may believe someone it is illegal for someone to drive because they are high, while the driver feels they are not.

Why is there No Legal Limit for Driving While High on Marijuana?

The biggest problem with establishing a legal limit for marijuana consumption prior to driving is that people respond to the drug in drastically different manners, which makes even testing for intoxication nearly impossible. Age, weight, body composition, genetics, the type of marijuana, and how frequently a person uses the drug all play a part in how stoned a person will get after using it. Some people will take a puff of marijuana and be unable to get off the couch, while others can smoke all day and barely have any detectable level of impairment.

Unlike alcohol, which dissolves in water, THC dissolves in fat. For this reason, the speed of elimination of THC from the body varies from person to person. A Colorado study showed THC showed up in significant amounts 30 days after some people’s last usage, while some subjects showed no THC in their blood immediately after using marijuana. These results have led some scientists to try and develop a breath test for marijuana, although minimal THC shows up in breath, and it dissipates quickly.

A study by UCSD found that while driving on weed did significantly impact the driving ability of some users, others were not significantly impaired. The study also found that the amount of THC in the marijuana samples did not affect the driving skills of the users, nor did it increase the concentration of THC in the user’s blood. Overall, the effects seemed to wear off after about 3.5 hours.

Users who regularly used marijuana had higher THC blood concentrations than those who did not, yet they performed equally well on the driving simulator. All of this indicates that a “per se” law defining what level of marijuana blood concentration someone can have prior to driving is not useful from a scientific perspective.

What are the Penalties for a Marijuana DUI in California?

The consequences for a cannabis DUI are the same as those involving the use of alcohol. For first-time offenders, this means:

• up to 6 months of jail time
• up to 6 months of DUI school
• a fine of up to $1000
• a penalty assessment equal to 180% of the fine
• a 6-month license suspension

While drivers convicted of drunk driving in California can avoid the license suspension by installing an ignition interlock device, those convicted of a marijuana DUI do not have this option available to them.

How to Beat Marijuana DUI Charges

To secure a conviction for DUI, prosecutors must prove that you were under the influence of the drug while you were driving. Your defense lawyer is critical to helping you fight the evidence that indicates you used marijuana or that marijuana use affected your driving abilities, which could include:

• arguing that there is a lack of scientific evidence proving that marijuana negatively affects driving ability
• showing there is too little evidence to prove your guilt
• questioning the officer’s testimony
• challenging the chemical test results
• retesting the blood sample
• arguing that you were not under the influence while driving

If the prosecution cannot prove that you were under the influence of the drug when the police stopped you, you cannot be found guilty. Even if you were under the influence of cannabis while driving, the prosecutors must also show that it negatively impacted your driving, which is a relatively difficult standard to meet.

If you have been accused of driving under the influence of marijuana in San Diego, please call DUI lawyer Peter M. Liss at (760) 643-4050 to schedule a free consultation.