Yet another driving study that confirms what we already know. This one specifically compared THC intoxication and alcohol intoxication.
THC primarily caused elevation in physical effort and physical discomfort during the drive while alcohol tended to affect sleepiness level. After THC administration, subjects drove significantly slower than in the control condition, while after alcohol ingestion, subjects drove significantly faster than in the control condition. No THC effects were observed after 24h on any of the measures.
No, it’s not good to drive while impaired in any way, including being tired, or talking on a cell phone, or under the effect of prescription drugs. But there is a dramatically different danger of driving drunk compared to driving under the influence of marijuana.
Those on marijuana, as a rule, drive more cautiously because they are aware of their impairment, while those on alcohol drive more recklessly. This is why the boogieman of roads full of drugged drivers from marijuana legalization is such nonsense.