Drinking and driving is a common activity for millions of Americans and that is unlikely to change in our lifetimes. I think harsh penalties and public awareness have certainly helped curtail it, but there is a limit to what we can do.
Look at recreational drugs. We've spent untold billions over decades, curtailed civil liberties, enacted extreme penalties, ruined countless lives and what has it gotten us? You can still easily buy coke, meth, heroin, whatever you'd like in every city and town in America.
People should not be drinking and driving... but they will. So what do we do with this reality?