With Uber and Lyft there should be zero DUI's now.This is why its cheaper to call a Taxi than to do any of the other things.
However, it also depends on the private property. If you were at a friends house, had too much, and slept it off in your car, you probably wouldn't get hit for it. However, the guy was drunk, in the drive through lane, at an establishment that doesn't sell alcohol. Its kinda obvious he was drunk before he got there, so easy to say he was DUI.
We use them all the time when going out if we anticipate having alcohol. That $20 or so plus tip is cheaper than a 20 grand expense for a DUI.