I stumbled across an interesting chart at the Governor's Highway Safety Association which purports to be an accurate compendium of drunk driving laws state by state. http://www.ghsa.org/html/stateinfo/laws/impaired_laws.html.
There can be little doubt that drunk driving routinely contributes to horrific crashes resulting in wrongful death and serious injury.
It is fascinating to scroll through state by state to see the variability. For example Virginia and the District of Columbia are among the most lenient states when it comes to license suspension on first dui offenses. How lenient? Where in Georgia the penalty can be a one year license suspension in the District it can be as little as two days! In Virginia its a week!
How about increased penalties for high blood alcohol levels? In Tennessee, Florida, Minnesota and Idaho, they don't kick in until .20. elsewhere it is typically .15.
The bottom-line efforts to curtail drunk driving crashes are ongoing but sporadic.