Dude, if someone is drunk in a bar, it doesn't mean they will leave by car. Ever heard about the concept of taxi? Or better yet, walking!! Besides. Some people still retain their sanity (relatively speaking) even if they are totally drunk. A person can be totally wasted and still behave like a responsible (drunken) human being, and then ask the next morning if they did anything stupid 'cos they can't remember a thing.
30 people from 36 bars seems a pretty high number for me. What I consider to be too drunk, is when person is rolling over the floor and not being able to walk without causing harm to himself and others. Basically not able to take care of himself anymore. I don't know about texas. But around here, if I visit 5 bars, chances are that in one of them is a person who who qualifies as too drunk. But according to those numbers I should be seeing at least 4 of those cases. Then again, Finland and texas propably have different drinking habits and culture...