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Over the last few decades, the driving and general public have understood the inherent dangers of driving while under any influence of alcohol. As a result, new measures are in place to gauge the impairment of drivers, along with a host of improved car safety technologies to prevent harm. However, what about marijuana use? Is there such thing as “high driving,” and how much is too much?

With so many states moving to legalize the marijuana industry, more and more consumers are recreationally taking part. The question lies in whether or not those people are risking themselves or others when they climb behind the steering wheel. So, while there are clear car safety guidelines and benchmarks for what constitutes a legal limit for alcohol consumption, what are the rules about pot? Is driving high as dangerous as driving drunk?

The differences between driving drunk and driving high

A man suspected of drinking and driving taking a breathalyzer test
A man taking a breathalyzer | Michal Fludra/NurPhoto via Getty Images

It’s important to discuss car safety in terms of understanding impairment definitions. Because marijuana is legal in more and more jurisdictions and across more states, as The New York Times points out, consumers may be wondering about the legality of operating a vehicle while under the influence of pot. When you compare the usage and regulation model of how alcohol impairment is determined, you might wonder what metrics are in place to gauge the impairment of those using marijuana. How high is too high to drive? How can someone tell how much marijuana has been consumed? More importantly, is it just as or more dangerous than drunk driving?

Not a lot of data has yet been collected regarding high drivers or motorists being cited for impaired driving with pot as the primary substance. However, The Marshall Project suggests that “most [but not all] studies find that using pot impairs one’s ability to drive.” They go on to say it appears, however, that “overall impairment is modest,” citing it roughly equates to a blood alcohol content of .01 or .05, which falls under the legal limits of alcohol consumption in all 50 states.

Driving high still means impairment

Let’s be clear, ingesting any form of marijuana will affect users in very different ways. A marginal amount for one person might constitute a total high for someone else. Additionally, depending on which state you’re in, there still may be zero-tolerance policies. Still, car safety boils down to knowing your limits and avoiding any substances or distractions that could impair you as a driver. The Florida Highway Safety and Motor Vehicles website says, “driving high is driving impaired” and warns motorists that even the slightest pot-induced impairment can lead to injury to yourself or others.

It’s also important to also point out that while marijuana use isn’t always as impactful as drunk driving, combining pot with alcohol or other medications presents a much greater risk when driving. So, anyone recreationally and legally partaking in marijuana use should be mindful to identify when they are, in fact, too impaired to drive. Some self-diagnosing signs might include a slowed reaction time, decreased hand-eye coordination, limited short-term memory capacity, or weakened concentration. If you can’t stay focused or feel slightly off, it’s probably best to hand the keys over to someone else.

Pot may be legal in many states, but driving in an impaired state is illegal no matter what the cause. The IIHS reported recent data that points to marijuana-impaired driving as the catalyst behind surges in crashes. Those states with legalized marijuana have higher rates of roadway incidents. States including Washington, Nevada, Oregon, California, and Colorado presented 6% increases in injury crash rates and 4% increases in fatalities from crashes. In other studies, where ER patients were interviewed and prompted about their marijuana use, 13% of crash-involved motorists tested positive for pot.

So, is driving high as dangerous as driving drunk? The verdict is still out for official car safety determinations. Still, for many individuals, marijuana isn’t going to impair them as much as alcohol. It’s best for all drivers to self-regulate to know when to let someone else take the wheel. It’s still too dangerous of a risk to gamble with your life or the lives of others on the road.


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