This just goes to prove what I was talking about in my original post on sobriety checkpoints.  They are used by police as dragnets to look for minor offenses to raise revenue, while not helping public safety one bit.  Here is a story about police in DeForest using "fake checkpoints" to ticket people:

This weekend DeForest police will again be intentionally creating the false impression of a random checkpoint for drunken drivers.

Random checkpoints are illegal in Wisconsin and 11 other states.

About three weeks ago, police set up a fake checkpoint along Highway V. Officers wore bright reflective vests, set up cones and electronic road signs warning of a "OWI task force ahead."

But instead of pulling over drivers randomly, officers stopped motorists for any infractions they spotted, including a broken license plate light. That effort resulted in 10 citations, 30 warnings and one non-alcohol-related arrest.

Dane County has had 29 traffic fatalities so far this year, 15 of which were alcohol-related.

You'll notice that the last time they did this, there were no arrests for drunk driving.  They didn't find a single drunk driver.  Yet immediately after they talk about what they did find, they try to justify this with statistics about drunk driving, despite the fact that they didn't arrest any in this dragnet.  In fact, I would venture to guess that by putting up signs advertising an "OWI task force ahead", they are actually going to scare drunk drivers into finding other roads home, and avoiding the checkpoint.

I would guess that the actual purpose behind the signage is to lull drivers into a false sense of security.  Have a broken tail light?  You think you'll go through just fine because you haven't been drinking.  That is until, surprise, you get nailed with a ticket.  In the mean time, the guy who just slammed down a couple extra car bombs with his buddies before driving home turned onto a side road and crashed into your neighbor killing their child in the passenger seat.  But hey, at least they stopped your dangerous broken tail light.

Drunk driving is a problem.  The solution is to have stricter penalties for multiple offenders, and better roaving patrols which look for actual evidence of drunk driving, like swerving in your lane, stopping for green lights, driving unusally slow, etc.  Cops at checkpoints can't do that.  And there is no guarantee that a drunk driver has a broken tail light.