I admit, I'm not a great designated driver. The thing is, I don't go into bars. I was designated driver once, for my brother Erik's bachelor party. I was the first to conk out for the night. The reason was that I can't handle cigarette smoke. At all. The plan was that Erik, me, and a couple of his friends would bar-hop around town over the course of the night. The first bar they picked was filled with smoke. There was a visible haze in the place. After half an hour, I needed to go outside for air. The second bar wasn't nearly as smoke-filled, but I was so out of it from the smoke of the first bar that, after a grand total of one hour, I had to go home and lie down for the rest of the night.
That's right, I wasn't even drinking and I still tapped out before anyone else in the group. (They walked the rest of the night and I believe they called a cab to get home.)
But I had two jobs that night. To drive everyone else around, and to not drink. I flunked out at driving, because, well, I had to take the car to get myself home to lie down. But I fulfilled my other job: to not drink.
In that respect, I appear to have outperformed some people. Let's first note that the study we're about to quote here, published in the Journal of Studies on Alcohol and Drugs, had a sample size of only about 1,100 people and that most of the subjects were students in an unnamed Southeastern college town. The college students will skew things high, but the Southeastern location, taken broadly, will actually skew things low depending on where exactly we're talking about (the north central, Big Sky region of the country, that's where things skew high). On the whole, we're probably talking a high skew. But given that sample set, they had 40% of designated drivers as having had a drink on their night to drive, and 20% of the drivers drinking enough to get themselves to at least a .05%.
However far the number overshot (or undershot) reality, though, what is beyond dispute is that this means the number is not zero, which is the entire point of having designated drivers in the first place.
The funny thing is that we're assuming people in the process of receiving a higher education to be MORE likely to be this particular brand of stupid.