There is not a lot of road rage among stoners, or likely the kind of behavior that provokes road rage in others. The British study concluded that fatigue was a much more serious problem than drug taking. Don t hold your breath waiting for the government to put a curb on, or start regulating worker's overtime, or to put other restrictions on automobile commuters. People who take illicit drugs are trying to escape from reality, we are told. But the real escape from reality is lies.
Drugs merely alleviate some of the pain from unpleasant truths.
Lies hide the truth, and hide the unpleasant consequences of the truth for a while. Hence, the War Against Reality waged by those on the business end of the War On Drugs. We don't need any more studies. What fuels the drug war is lies not studies. Studies are a hindrance.