I know you all have thought of this already...

But one of the things that we have found is that "X marks the spot" actually works. For everyone. Even our most frustrating 15-16 year olds. If we put cones out on the sidewalk in the morning, each kid will stand by one.

Can you put out some extra benches, put Xs 1.5-2 meters apart, and tell the kids they can only sit on an X?

It is never going to be perfect--all of this is an exercise in cat-herding. Kids can't do social distancing--they don't mean to do it wrong, they just can't get their heads around it. But anything you can do to help will actually help.