I had never even considered the blood test as a means of eradicating an impairment conviction. That is a good point. It is still unfortunate that things would have to go soooo far and people win lawsuits for being detained and getting towed before someone sees that this is not actually much of an improvement in methodology for preventing drunk driving. A better approach would be to limit liquor licenses and not allow service vehicles out certain hours such as 12-5am which are the main problem hours of people leaving a bar drunk driving. Of course just as you said some people are determined to drive around drunk and people have even been caught driving drunk within days of getting out of prison for DUI nearby so I'm not surprised at the lack of responsibility shown by many people these days. Let's not forget about historic laws such as prohibition which didn't work to prevent drunk driving deaths either when trying to solve problems. Drunk driving will most likely continue to happen unless everyone has to use a breathalyzer lock to start their ignition but we don't want to wake up in a society that extreme do we?