I would have tested positive for the last 40 years.lol What about people on prescription drugs? They're far more dangerous on the road than cannabis patients. The effects of cannabis smoke wears off after a couple of hours. There's no legitimate reason why you can't drive. There's an interesting documentary called' Should I Smoke" where a journalist tried a scientific approach to the differences between drinking and driving and cannabis and driving. She wasn't much of a threat while high but she sure was on alcohol.lol