Back when I was into partying I collected keys as people arrived. If I noted anyone drinking or drugging, I put their keys into a lock box. All owners of lock box keys had to stay. Plain and simple. I drove tractor/trailer trucks for years and I have seen the results of many drunk drivers. It is something I can't stand - when someone allows a drunk to drive. Yes I am aware that the fault is the drunk, but I also am aware that it is far safer to be the "bad guy" and not allow the drunk to drive.
I went to OKC a few years. back to attend my parent's 50th wedding anniversary. The party was at a lovely country club and the alcohol was plentiful. My Dad got enough liquor in himself that he was not able to walk in a straight line. I had my Princess with me for the trip, she was 4. I quit all alcohol May 16, 2001 (not keeping track, lol) Anyway, I asked my Dad for the keys, he said No that he was fine. My sister said that he drives drunk a lot. I didn't make a scene at the party and my Sister brought us back to my Parents house. My Dad was ******, but he didn't remember that part the next morning. Ahem . . .