I believe that all the drinking laws actually contribute to drunken driving. This is because these laws create a climate where one wants to "drink as much as possible when one can". Thus we have underage teens drinking unsupervised in places that they usually have to drive out to. Or adults on their way to a place where drinks are either limited or not allowed will tend to drink heavily before going to these places.
Here most people will drink and drive because you are just as likely to get a public intox ticket if you decide to walk home. Most people figure you might as well limit your exposure and just drive home from the bar instead of walking. Either way you could land in the drunk tank.
Interesting point. And I mostly agree with you. Laws generally do not take into consideration all the cultural, psychological, cultural factors that determine behavior patterns resulting from alcohol consumption.
What our society needs to get to is a way to allow people to drink without the resulting/accompanying mayhem. And certainly prohibiting the selling of "cold ones" does nothing to solve the problem.