Performance Enhancement or DUI? Why Science Says You Might Drive Better High (But the Law Disagrees)

By: John Guidry

Professional athletes are always trying to optimize their performance. That’s their job. Training helps. Diet helps. And yes, drugs help. For every honest athlete, there is a Lance Armstrong waiting to be caught. The simple fact is: Some drugs enhance performance.

So, if athletes use marijuana to help them focus or relax without diminishing their physical skills, why is it automatically a crime to drive with it in your system? The Science says one thing. Florida Law says another.

Did you get a DUI for smoking weed days before you drove?

Presence is not Impairment. Call John today at (407) 423-1117.

The “Vast Majority” Reality (Alcohol vs. Weed)

You’ve heard my rant before, so I’ll spare you the 1,000 words.

• Alcohol: The vast majority of domestic violence, bar fights, and deadly crashes come from alcohol.
• Marijuana: Rarely do we hear of a wife calling 911 because her husband smoked too much weed and got violent.

Yet, Florida law treats driving with THC in your blood just like driving drunk.

The Shocking Studies (Cocaine & Weed)

I hate to use the cliché, “Recent studies have shown,” but I have no choice. Stimulants: Some studies suggest that stimulants (like cocaine or amphetamines) can actually lower crash risk compared to driving sober because they increase alertness.

• Disclaimer: Do NOT drive on cocaine. Traffic judges are not going to prescribe stimulants to sleepy drivers. It is still a crime.

Marijuana: The most common way to study safety is to examine raw crash statistics.

• NHTSA Study (2015): The National Highway Traffic Safety Administration found “no increased risk of crash involvement for those drivers testing positive for THC” once you adjust for demographics (age/gender).
• The Conclusion: They found no evidence of a causal relationship between having detectable THC and crashing.

The “Per Se” Limit Myth (5ng/mL)

Everyone knows the .08 limit for alcohol. It is a scientifically accepted number for impairment. Governments are desperate to set a similar number for weed (like 5ng/mL). The Problem: Science says that number doesn’t exist.

A landmark study by the AAA Foundation for Traffic Safety (2016) examined this exact question.

• The Finding: “There is no evidence… that any objective threshold exists that establishes impairment based on THC concentrations.”
• Translation: You can have high THC levels and be a safe driver, or low levels and be impaired. A number in your blood cannot scientifically prove you are unsafe.

And there you have it. Science is siding with the weed smokers. Do you think the government will listen? Don’t hold your breath.

John’s 2026 Update: Saliva Tests & The “DRE” Scam

Note: In 2016, we argued about blood tests. In 2026, the police are trying to test your spit on the side of the road.

1. The “Roadside Saliva” Trap In 2026, Florida police are rolling out portable Oral Fluid Test Kits (like the Dräger DrugTest 5000).

• The Pitch: They claim it detects “active” use within the last few hours.
• The Defense: These machines are notoriously finicky. They have high false-positive rates for legal medications and can be contaminated by food or drink. We fight to suppress these results as “junk science” that hasn’t met the Daubert standard for reliability in court.

2. The Rise of the DRE (Drug Recognition Expert) Because they can’t rely on a “number” (like .08) for weed, the State relies on Drug Recognition Experts.

• What they are: Officers with extra training who supposedly can look at your eyes and tell you are high.
• The Strategy: We expose the subjectivity. We cross-examine them on the AAA Study mentioned above. If science says there is no physiological correlation between THC levels and impairment, how can a cop with a flashlight determine it better than a toxicologist?

3. “Actual Physical Control” & Medical Cards In 2026, many of my clients have Medical Marijuana cards.

• The Warning: Your card protects you from a Possession charge, but it offers ZERO protection against a DUI charge.
• The Scenario: If you decide to “sleep it off” in your car with the keys in your pocket, you can still be arrested for DUI (Actual Physical Control), even if you weren’t driving.

Science is on Your Side. Is Your Lawyer?

The government wants to convict you based on bad science and fear. We use the actual data—from the NHTSA and AAA—to show the jury that “THC Presence” does not mean “Bad Driver.”

Call me at (407) 423-1117. Let’s look at the data.

About John Guidry II

John Guidry II is a seasoned criminal defense attorney and founder of the Law Firm of John P. Guidry II, P.A., located in downtown Orlando next to the Orange County Courthouse, where he has practiced for over 30 years. With more than three decades of experience defending clients throughout Central Florida since 1993, Guidry has successfully defended thousands of cases in Orange, Seminole, Osceola, Brevard, Lake, and Volusia counties. He has built a reputation for his strategic approach to criminal defense, focusing on pretrial motions and case dismissals rather than jury trials.

Guidry earned both his Juris Doctorate and Master of Business Administration from St. Louis University in 1993. He is a member of the Florida Bar and the Florida Association of Criminal Defense Lawyers. His practice encompasses the full spectrum of Florida state criminal charges, with a particular emphasis on achieving favorable outcomes through thorough pretrial preparation and motion practice.

Beyond the courtroom, Guidry is a prolific legal educator who has authored over 400 articles on criminal defense topics. He shares his legal expertise through his popular YouTube channel, Instagram, and TikTok accounts, where he has built a substantial following of people eager to learn about the law. His educational content breaks down complex legal concepts into accessible information for the general public.

When not practicing law, Guidry enjoys tennis and pickleball, and loves to travel. Drawing from his background as a former recording studio owner and music video producer in the Orlando area, he brings a creative perspective to his legal practice and continues to apply his passion for video production to his educational content.