If you actually believe its about driving drunk, where they already can do a Breathalyzer or blood sample? i have a bridge you might be interested in. Its about getting as many citizens in as they can into their DB, specifically the poor. they know the person driving that Lexus is gonna tell them to get bent while the mother of 3 in that 94 Dodge? Not so much.
I never thought I'd say this but I'm glad my beloved grandfather and great uncles are gone, they fought against fascism in WWII and this kind of gestapo shit would disgust the hell out of them. I could probably wrap his body in some copper wire and run my entire neighborhood from all the revolutions he's turning in his grave.
I urge everybody who hasn't seen it to watch Naomi Wolf's lecture which shows how shit like this and the TSA intimidation fits into the bigger picture, because its fucking SCARY folks. This is the same plays that have been run since the time of Lenin and El Duce, get the population used to being confronted, cowed down and intimidated, makes things easier when they inevitably clamp down. Never forget that in 1930 Germany was a democracy and the NSDAP was a fringe bunch of kooks. Countries don't go from free to non free slowly, the shift is VERY fast but there is warning signs that a shift is occurring. I'd say shit like this and the NSA watching everything you do would be good indicators.
For those that think this kind of shit doesn't have a chilling effect? remember that when the wall fell it was found that the STASI had less than 7% of the population on their lists yet the entire population lived like they were always under the boot because everyone thought that they were one of the 7%. It really doesn't take much to break the will of a populace, just intimidation and fear used in the right places.