I will say that ,I think Americans are a bit slow to catch on.... As a teenager in the late 60's, drinking and driving was, oddly enough, quite socially acceptable. Now, totally blitzed wasn't - but that is a fine line of course.
In the mid-70's while working for my Uncle (Sam) I got to visit a wireless site, near Scarborough, UK. That was a fun thing, for a Navy guy to leave the uniform behind and meet up with some civilians for a couple of weeks. Back to the story... Living miles form any US presence we had time to visit local pubs and sample the nightlife - and it was there, that I first became acquainted with the "designated driver" concept - in action. It seemed wherever there were 3 or four people, one was drinking water with lemons, or something.
Now I wasn't there long enough to understand the ramifications for breaking the law for drinking and driving - but I was duly impressed that (young) people would be that focused. Certainly, people I knew back home weren't doing that.
So - kudo's to y'all in the UK for being the example.