Can you be arrested or charged with a marijuana DUI in San Diego? Yes — even though recreational cannabis is legal under Prop 64, you can still face marijuana DUI charges if an officer believes your driving was impaired. California DUI laws make it illegal to operate a vehicle under the influence of any drug — including marijuana — no matter how it was obtained or used.
If you’ve been pulled over for suspected marijuana DUI in San Diego, you could be facing serious legal consequences, even if you thought you were driving responsibly. Prop 64 may have legalized recreational cannabis, but it did not change how DUI laws are enforced. Officers across San Diego continue to make marijuana DUI arrests based on questionable indicators and testing methods that do not reliably prove impairment.
Call Sevens Legal now at (619) 430-2355 for a free legal consultation with a skilled San Diego criminal defense lawyer who knows how to fight marijuana DUI charges and protect your license, record, and future.
Key Takeaways
• You can be arrested for marijuana DUI in San Diego even without clear proof of impairment.
• California law doesn’t define a specific THC limit, unlike alcohol’s .08% benchmark.
• Police rely heavily on appearance, driving patterns, and officer discretion at the scene.
• THC can remain in your body long after any impairment has worn off.
• Field sobriety tests are not required, and often work against you.
• A San Diego defense attorney can challenge unreliable evidence and protect your record.
Marijuana DUIs operate in a legal gray area that’s still being debated in California courts. Unlike alcohol-related cases, there’s no reliable test or standard that clearly proves impairment, making it even more important to understand how police build these cases and how a defense attorney can break them down.
What Does Prop 64 Mean for Drivers in San Diego?
When it was passed in 2016, Proposition 64 made it legal for adults 21 and over to buy, possess, and use marijuana in California. You can now legally carry cannabis, visit dispensaries, and consume it in private. But when it comes to driving, the law draws a hard line.
Prop 64 does not, however, protect you from a DUI arrest in San Diego. Under California Vehicle Code § 23152(f), it remains illegal to operate a vehicle while impaired by any drug, including marijuana. If an officer believes you’re under the influence of marijuana, you can still be arrested.
THC doesn’t follow the same rules as alcohol when it comes to impairment. California has not set a universal standard for how much THC indicates someone is unfit to drive. Since cannabis can remain in your system long after the effects wear off, testing positive doesn’t always mean you were impaired behind the wheel.
The Realities of Being Stopped for Marijuana Impairment in San Diego
When you’re pulled over under suspicion of DUI in San Diego, the first few minutes matter. Officers often begin assessing impairment from the moment they approach your window. They’ll look for:
- Bloodshot eyes
- Delayed reactions
- Nervousness
- The smell of marijuana
- Slow speech
Even if you haven’t used marijuana in hours, these signs of impairment alone can lead an officer to suspect you of driving under the influence. If they do, you may be asked to step out of the car, perform field sobriety tests, or submit to a blood draw.
Without a measurable THC threshold, these encounters often come down to officer opinion. And that’s where a seasoned San Diego drug lawyer can begin building your defense.
What Evidence Do Police Use to Prove Marijuana DUI in San Diego?
Unlike breathalyzer results in alcohol DUIs, driving behavior alone isn’t enough to prove marijuana impairment in San Diego. Still, officers often point to minor swerving, rolling stops, or wide turns as justification for making an arrest.
While these infractions may raise suspicion, they don’t confirm impairment—especially in San Diego, where traffic flow and street design can naturally affect how drivers navigate the road. An experienced San Diego marijuana lawyer can challenge these assumptions and help undermine weak evidence in court.
Can You Refuse a Field Sobriety Test for Marijuana DUI in San Diego?
Field sobriety tests may seem routine, but they’re entirely optional under California law—and in marijuana-related stops, participating can work against you. These tests, like the walk-and-turn or one-leg stand, were originally developed to measure alcohol impairment. They weren’t designed to assess cannabis use, and their results often don’t reflect actual ability or sobriety.
Factors like anxiety, exhaustion, uneven pavement, or medical conditions can all cause someone to “fail,” even if they’re completely sober. Declining to take these tests isn’t just within your rights—it may be one of the smartest legal decisions you make.
How Reliable Is THC Blood Testing for Marijuana DUI in San Diego?
Blood tests are one of the most common tools police use to try to confirm marijuana use after a DUI stop, but they’re also one of the most misleading. Unlike alcohol, THC doesn’t metabolize in a predictable or consistent way. It can remain in the bloodstream for days—or even weeks—depending on the person’s metabolism, frequency of use, and product potency. That means someone could test “positive” long after any impairment has worn off.
Even more concerning, there’s no scientifically accepted THC threshold that reliably indicates when a driver is impaired. A regular cannabis user might show elevated THC levels while being completely sober, while a new user might be impaired with only trace amounts.
Law enforcement agencies are experimenting with nanogram-based testing devices, like one developed at Stanford, but these tools are still in the early stages and haven’t been validated in court. Until there’s a reliable, legally accepted standard for marijuana impairment, prosecutors often rely on flawed, unproven, or circumstantial evidence, and that opens the door for a strong legal defense.
What San Diego Criminal Defense Attorney Kerry Steigerwalt Wants Drivers to Understand
In the video above, San Diego criminal defense attorney Kerry Steigerwalt explains why marijuana DUI cases are some of the most legally uncertain and heavily contested charges in California. Without a clear scientific standard for THC impairment, these cases often come down to officer opinion, not objective proof. That leaves room for mistakes, assumptions, and overreach by law enforcement.
Kerry emphasizes a critical truth: legal cannabis use does not protect you from a DUI arrest. In San Diego, officers may base their decision on how you look, how you speak, or how you choose to respond, not on any actual evidence of impairment.
That’s exactly why having an experienced criminal defense attorney is essential from the moment you’re accused. A skilled lawyer can step in quickly to challenge faulty observations, suppress unreliable test results, and protect your rights in a system that still lacks clarity around cannabis laws.
If you’ve been arrested for driving high, watching this video is just the beginning—your next step should be calling a San Diego marijuana DUI attorney who knows how to fight these cases and win.
What Are the Best Legal Defense Strategies for a Marijuana DUI in San Diego?
If you’ve been charged with a cannabis DUI, you still have options. A San Diego DUI defense lawyer can challenge:
- The legality of the traffic stop
- The officer’s field assessments
- The accuracy and timing of your blood test
- The reliability of DRE (Drug Recognition Expert) evaluations
- Gaps or inconsistencies in the police report
Sevens Legal builds strong defenses by exposing weak evidence, cross-examining officer training, and presenting expert analysis to counter unreliable testing.
What Happens After a Marijuana DUI Arrest in San Diego?
Getting arrested for a marijuana DUI in San Diego is only the start of a complicated legal process. From the moment you’re released, two urgent timelines begin: a DMV hearing that could suspend your license, and a criminal case that can lead to probation, mandatory classes, steep fines, or even jail.
These charges carry more than legal penalties—they can damage your job prospects, housing applications, and long-term record. But here’s the good news: an experienced San Diego marijuana lawyer can intervene early, build a strong defense, and help you avoid the worst outcomes. The faster you act, the more control you have over what happens next.
Free San Diego Marijuana DUI Consultation
Sevens Legal offers free consultations to help you understand your charges, your options, and how to fight back. Whether this is your first offense or you’ve faced charges before, we will assess your case with urgency and strategy. We don’t just handle court appearances—we fight to protect your license, your record, and your reputation.
How to Contact Our Criminal Defense Attorneys
If you or someone you love is facing a marijuana DUI charge in San Diego, time is critical. Call Sevens Legal at (619) 430-2355 for a free consultation with our seasoned criminal defense attorneys. We have the experience, knowledge, and expertise you need. Let us help you take the first step toward protecting your future.
FAQs About Driving High in San Diego: How Prop 64 Affects DUI Arrests?
What is considered driving high in San Diego?
Driving high means operating a vehicle while mentally or physically impaired by any drug, including marijuana. This includes slower reaction time, poor coordination, or difficulty concentrating. Even if marijuana is used legally, if your ability to drive is compromised, you can be charged with a DUI in San Diego.
How do police test for driving high in California?
Police may use a combination of field sobriety tests, observations, and blood tests to judge potential marijuana impairment. They often call in a Drug Recognition Expert (DRE) to check for signs of drug impairment. However, none of these tests are foolproof, and many can be challenged in court.
What is Prop 64 in San Diego?
Prop 64, or the Adult Use of Marijuana Act, legalized recreational cannabis for adults in California, including San Diego. It allows possession and private use but does not legalize driving under the influence of marijuana. DUI laws still apply under Vehicle Code § 23152(f).
Can I get a DUI even if I used marijuana legally?
Yes. Legal use of marijuana does not protect you from DUI charges in San Diego. If an officer believes your driving is impaired, you can be arrested—even without a measurable THC limit. That’s why defending marijuana DUI charges requires experienced legal guidance.
Do I have to take a field sobriety test in San Diego?
No. Field sobriety tests are optional under California law. You can politely refuse them. These tests are highly subjective, and your performance may be misinterpreted. Consulting a lawyer as soon as possible is critical after any DUI stop in San Diego.
Disclaimer: The information provided in this blog is for informational purposes only and does not constitute legal advice. Every legal situation is unique, and the laws referenced may not apply to your specific circumstances. You should not act or rely on any information in this article without first consulting a qualified criminal defense attorney. To receive legal guidance tailored to your case, contact Sevens Legal for a confidential consultation.