Driving Under the Influence of Marijuana
To some extent, marijuana and the use of cannabis has become legal in many states. But what if it is in your system when you are behind the wheel? Here’s what you need to know about driving under the influence of marijuana.
Driving While High Isn’t Legal
Even in places where cannabis is legal for recreational use (such as California and Nevada), and even if you have been approved for medical marijuana, it is still illegal to drive while you’re under the influence of marijuana. You get can arrested for a DUI while driving under the influence of marijuana.
How Do I Know When I’m OK To Drive?
You may have seen infographics that provide you a ratio based on your height, weight, sex, and age, but these are not reliable. With alcohol, it is much easier to track the way the body reacts, absorbs, eliminates alcohol, and the resulting effects it has on you. It is much harder to track the effects of cannabis. NORML suggests that cannabis users wait a minimum of three to four hours after use before driving. and that users not drive while they feel impaired (which includes feeling “a little high” or “buzzed).
How Does Marijuana Impact My Driving?
Does consuming cannabis impair your driving ability? Does it contribute to car crashes? Though it’s generally agreed upon that you shouldn’t drive if you feel even “a little high,” as suggested by NORML, NHTSA’s report to Congress on “marijuana-impaired driving” points out that currently, no one has figured out how to measure how stoned someone is, or developed a tool similar to the breathalyzer, that can quickly and accurately be used roadside by law enforcement. NORML also offers some research on crash culpability and on-road performance.
From driving simulation research we know that using cannabis has been shown impair key driving-related skills including:
- Reaction time
- Tracking ability and target detection
- Cognitive skills (judgment, anticipation, and divided attention)
- Executive functions (route planning and risk taking)
Driving Under the Influence of Drugs (DUID) Laws and Marijuana
Five states (Montana, Nevada, Ohio, Pennsylvania, and Washington) have per se DUID laws which work the same way as alcohol per se laws. If a blood test shows that you have more than a specified amount of THC in your blood (generally 5 nanograms of THC per milliliter of blood), you don’t have to fail a Field Sobriety Test to be considered in violation of DUID law. (Colorado law also imposes a 5ng/ml THC in blood threshold but this threshold is not per se; a defendant may successfully argue that they were unimpaired despite having more than 5ng/ml THC in their system.)
There are also “zero tolerance” per se laws in 11 states (Arizona, Delaware, Georgia, Illinois, Indiana, Iowa, Michigan, Oklahoma, Rhode Island, Utah, and Wisconsin) which take things even further. In these states, anyone found with any measurable level of THC or one of its metabolites in their blood will be considered to be in violation of DUID law.
What Should I Do?
If you’re worried about getting a DUI or DUID while using marijuana (even if you’re approved for medicinal), the best advice is to avoid getting behind the wheel while you’re under the influence or impairment of cannabis. If you do, you’ll risk injuring yourself and others. DUIs can have lasting consequences. Learn more about DUI penalties here.