Some support that driving while under the influence of marijuana is safer than driving when drunk, saying that people who drive high always drive at slower speeds so even if they cause an accident, it's a much safer one.

Has any research been done on this?

This article states:

Evidence suggests we may not have as much to fear from stoned driving as from drunken driving. Some researchers say that limited resources are better applied to continuing to reduce drunken driving. Stoned driving, they say, is simply less dangerous.

How much of this is true? What evidence exists?

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    I read some government statistics (in the USA, I think) that tentatively supported this claim, but because statistics on marijuana usage was not reliably gathered by all law enforcement agencies, it was hard to draw firm conclusions. As I recall, the most reliable data available for pot-related accidents were for accidents where both pot and alcohol were involved, obviously skewing the data.
    – Flimzy
    Commented Jan 15, 2015 at 4:56
  • Highly related question, where the answers mostly answer this question: Does marijuana impair driving? Commented Nov 22, 2022 at 17:46

1 Answer 1


Marijuana, alcohol and actual driving performance found that a 0.04 g/dL alcohol concentration resulted in minor impairment, while 200 mg/kg THC resulted in moderate impairment, and the two combined even at lower doses resulted in the most severe impairment.

It really depends on what dose you're trying to compare.

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    Well let's say one weed cigarette vs the slightly above the legal ratio of alcohol consuming Commented Jan 18, 2015 at 7:38
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    @JohnDemetriou because marijuana is still largely illegal, its growth is unregulatted, making it impossible to say what the exact dose for any given joint is. Different subspecies of cannabis have different concentrations of THC and there is no organization around (yet) to organize that kind of information. That's going to make it hard to put solid numbers behind your question.
    – KutuluMike
    Commented Jan 18, 2015 at 13:39
  • Hopefully the Google link will change over time and new information will be reflected there.
    – jmabs
    Commented Jan 18, 2015 at 16:20
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    @jferr: If it changes, your answer should be updated too.
    – Oddthinking
    Commented Jan 18, 2015 at 16:36
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    @Oddthinking, yes, someone should probably go through every StackExchange question that has ever been asked and update them as new research is published, but that is never going to happen.
    – jmabs
    Commented Jan 18, 2015 at 16:45

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