I don’t have any data on it, but I get the idea that checkstops are pretty effective—I’ve overheard quite a few times people saying stuff like, “Oh, I have to call a cab; the cops are probably out checking tonight.” I mean, kind of grim—you’d think the risk of killing someone would be enough to stop most people—but if it works, it works. Of course, the drinking age in Canada is 18 or 19 depending on the province, so I imagine our drunk driving stats are pretty bad anyway...?