Marijuana vs. Alcohol OWI in Wisconsin: What You Need to Know

by | May 8, 2025 | Blog, Criminal

Key Differences Between Marijuana and Alcohol OWI - A comparison table outlining legality, detection methods, impairment standards, field tests, and penalties for marijuana versus alcohol in Wisconsin.
Driving under the influence of any substance is a serious offense, but when it comes to marijuana and alcohol, Wisconsin handles each a bit differently. With marijuana still illegal in the state, an OWI (Operating While Intoxicated) charge for marijuana can carry unique consequences and legal challenges. In this guide, we break down everything you need to know about OWI for marijuana versus alcohol in Wisconsin.

Understanding OWI in Wisconsin

In Wisconsin, an OWI charge applies to anyone operating a motor vehicle under the influence of drugs or alcohol. Unlike alcohol, where impairment is measured by a specific blood alcohol concentration (BAC) level (0.08% or higher), marijuana OWIs are determined by any detectable amount of THC, the psychoactive component of marijuana, in your system. This is due to Wisconsin’s strict liability standard for controlled substances—meaning the state does not need to prove impairment, only the presence of the substance.

marijuana versus alcohol owi in Wisconsin

Testing Methods for OWI

  • Horizontal Gaze Nystagmus (HGN) – Eye movement tracking
  • Walk-and-Turn – Divided attention walking test
  • One-Leg Stand – Balance and coordination assessment

These tests are widely accepted for determining alcohol impairment. However, marijuana impairment requires different protocols. Officers are supposed to perform a Drug Recognition Evaluation (DRE)—a multi-step process that examines physiological signs of impairment, such as eye movement, muscle control, and cognitive response.

Legal Penalties for Marijuana OWI

  • First Offense: Traffic ticket with fines and license suspension
  • Second Offense: Misdemeanor with potential jail time, higher fines, and longer suspension
  • Third Offense and Beyond: Felony charges with significant legal consequences

One key difference: Wisconsin is the only state where a first-offense OWI is not a criminal charge, but rather a civil violation.

What to Do If Pulled Over for Marijuana OWI

  • Do not admit to recent use – Even saying you used marijuana days ago can be grounds for probable cause.
  • Avoid field sobriety tests if possible – Unlike alcohol, these tests are not as reliable for marijuana detection.
  • Consult a lawyer immediately – Early legal representation can challenge testing procedures, probable cause, and evidence collection.

Fighting a Marijuana OWI Charge

If charged with a marijuana OWI, the best defense is to challenge:

  • The validity of the traffic stop
  • Whether the officer followed DRE protocols
  • The accuracy of blood or urine tests

Contact Angela Olson Law

If you are facing OWI charges in Wisconsin, contact Angela Olson Law. With years of experience defending OWI cases, Angela can help you navigate the complexities of marijuana and alcohol-related charges.

Get the defense you need. Call Angela Olson Law today.

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