We certainly wouldn’t advise you to take the wheel of your car if impaired by alcohol or marijuana, but data from the National Highway Traffic Safety Administration shows that pot smokers don’t have that high a risk of crashing, as compared to drivers under the influence of alcohol.
The NHTSA’s analytical report shows that drivers impaired by marijuana use, as well as drivers using legal or illegal antidepressants, stimulants, or painkillers, are not that much more likely to crash their vehicles than if they were driving sober. However, those who drink alcoholic beverages and test for a blood alcohol concentration level of 0.05 or more are almost seven times more likely to be involved in a road accident.
Once again, we’re not telling you to go ahead and smoke your weed (as long as it’s legal where you live) before heading out of the house or driving back home, but the federal study does show statistical evidence that the presence of THC (weed’s active ingredient) in one’s system isn’t as dangerous as the presence of alcohol. According to the NHTSA, “specific drug concentration levels cannot be reliably equated with a specific degree of driver impairment.”
The study also notes that there are several variables that make the presence of drugs, marijuana included, less of an impairment than alcohol. “Most psychoactive drugs are chemically complex molecules, whose absorption, action and elimination from the body are difficult to predict, and considerable differences exist between individuals with regard to the rates with which these processes occur,” wrote the NHTSA. “Alcohol, in comparison, is more predictable.” It’s also worth mentioning that states that allow marijuana use for medical and/or recreational purposes have their own thresholds to determine whether a driver is under the influence – for example, Colorado’s blood THC threshold is set at 0.5 nanograms per milliliter.