One of the nice things that happened at my supermarket (and many others I visited) during the pandemic was they switched to the single-line set-up. That was pretty nice while it lasted.

How about the opposite of the new line opening up? On my first visit to China in 2002, I was at PVG in line to exchange some money back into USD. There were two windows and two lines. Abruptly, one window decides to close with no warning and those of us in line were expected to fend for ourselves, which meant politely getting into the back of the other line. Some folks decided to forcibly get into the other line in the middle. It was a bit of a mess and something I had never seen in my life.