Several years ago I had a brief stop at some airport-- maybe Atlanta? But they had an indoor smoking area. I smoked at the time so I followed the map, and you could see the smoking area from the balcony on the floor above.

It was a glass cube maybe 10 feet across, and it was crammed full of people. Completely full, like those Japanese trains. And there was a crowd of people outside waiting to get in.

I went outside. It was pretty nice, there was no one around.