Three drivers, plenty of pot, a driving course and a drug recognition expert from the local Sheriff's department. You know where this is going.
Three drivers from Washington state — where, last November, citizens voted to legalize recreational marijuana use — were recently asked to smoke up to (and, in one case, significantly more than) a gram of pot to provide insight on the drug's effects on driving abilities. The smokers were on a closed course, accompanied by a driving instructor, and observed by a member of the local law enforcement trained to spot drivers operating vehicles while under the influence.
The exercise is far from scientific (employing just three "test subjects" who varied in age and pot-smoking habits) but it's interesting and relevant — not just because of Washington's newly passed legislation, but also in light of several recently published studies on the effects of driving while high.
A 2009 review published in the American Journal of Addiction concluded that driving high is likely less dangerous than driving drunk, and a recent investigation by the Institue for the Study of Labor found that the legalization of medical marijuana in the United States has been linked to a dramatic decrease in traffic fatalities. That said, a study published last year in the British Medical Journal concluded that smoking pot within few hours of driving is still associated with a nearly two-fold risk of being involved in a serious car crash; as the video up top makes perfectly clear: driving stoned is still driving impaired.
We'd love to see this experiment repeated on a larger scale, with control (i.e. non pot-smoking) groups and blind assessments from the trained law enforcement (it's easy to say you'd pull someone over when you know the point of the exercise is to have habitual pot smokers get ripped out of their minds and have a go at a technical driving course).