I wouldn't agree with lining up all the bar patrons, but if someone comes out of the bar tipsy, can't we pull them over within seconds of them driving? It seems to be a good location to watch for drunk driving behaviour.
I saw an interesting tactic. The police had a Checkstop on a major road and it caused serious gridlock. Far down the road at an intersection, they had a sign indicating to have patience thanks to the Checkstop ahead. I was NOT drinking, but sure didn't feel like waiting 30-45 minutes in line, either, so I bailed at the intersection. Suddenly, I had a cruiser in front of me. They figured the people bailing were the most likely to be drunk, not just impatient.