I think there’s now going to be more focus on impaired, specifically weed-impaired, driving in Canada. People have been driving high forever, but very little noise has been made about it until recently. Now we’re going to get roadside piss tests, and I expect a lot more highway stops in general. If you want to be really paranoid about it (pot paranoia, whee!), government sales records could be a handy resource for police looking for people who need a roadside spot check.
As for people who think they drive better high: there might be a few such people, but they tend to be gigantic assholes because they tend to assume their own response to the drug is the same as everyone else’s, so they make a lot of noise about how driving high is just great, dude. Meanwhile, many people can barely open a bag of chips while baked, yet these bozos expect us to believe that people are not only good to drive but better drivers?