Not surprisingly, a new study from the National Highway Traffic Safety Administration states that drivers who are under the influence of marijuana have much less of a chance of getting in an accident when compared to drivers who are under the influence of alcohol.
It even goes as far to say drivers who used marijuana before driving are no more likely to get in any type of accident than someone who had no drugs or alcohol before driving. Alcohol increases your risks of a crash by almost 600 percent. This does not prove that marijuana has no effects on drivers, because it can impair important driving skills, but mostly with drivers who have either just recently toked, or only occasionally light up. It does suggest that the driver has about the same amount of probability of something happening to them than a regular driver, who is completely sober.
There is no perfect way to measure how much THC is in a driver’s system, and how greatly it affects driving skills. Colorado sets its limit to .5 nano-grams per milliliter. At that point, you are subject to a DUI. But, it’s hard to tell if that limit really affects the driver that greatly. There is even a pot breathalyzer in the works that will be for states that have marijuana legalized.
Here is a chart from the NHTSA that shows the odds of a wreck under certain influences.