Even though use of marijuana is legal in many states, driving under the influence of marijuana may be illegal. Find out why driving high is so dangerous, what the laws are in your state and how you can prevent marijuana impaired driving.

Why is driving high so dangerous?

According to SAMHSA, drivers who are high experience the following effects:

• Slower reaction time
• Trouble staying in one lane (lane weaving)
• Decreased coordination
• Difficulty reacting to signals and sounds

Any one of these effects make our share roadways a more dangerous place and can quickly lead to a motor vehicle crash. In fact, The National Institute on Drug Abuse notes “Several meta-analyses of multiple studies found that the risk of being involved in a crash significantly increased after marijuana use — in a few cases, the risk doubled or more than doubled.” Clearly, a high driver is a danger on the road.

Marijuana-Impaired Driving Laws by State

Laws regaring marijuana imparaired driving vary by state. For states that do have laws regarding marijuana impaired driving, they usually all involve tetrahydrocannabino or THC, since this is the main substance that can alter one’s mental state. The laws usually fall into one of the following categories:

• Zero tolerance for THC or a metabolite
• Zero tolerance for THC, but no metabolites restriction
• Specify a THC limit, anything above that is illegal

View the map at National Alliance to Stop Impaired Driving (NASID) for impaired driving laws in your state.

Prevent Marijuana Impaired Driving

Everyone knows that driving under the influence of alcohol is dangerous, but many people don’t think about the risk of driving high. Put into practice these tips:

• Never get into a vehicle with a driver who is high
• Don’t drive high – encourage friends and family to do the same
• Designate a driver or hire a rideshare service to get home safely

As marijuana becomes increasing popular, the effects on our roadways can be devastating if people choose to drive while high. Remember if you see a driver that is driving impaired, report it immediately to your local authorities. If you want to learn more about driving under the influence of drugs (DUID), check out our Safe Driving Module on Avoiding Impaired Driving.