I feel like the schools could tap the stay-at-home parent, whether that's Mom or Dad, to volunteer to stay outside the school boundaries but still just kind of police the playground from afar ... keep an eye on things. Recess is probably 2 - 3 hours each school day. Parents could coordinate so that they'd only have 1 day per week to cover during "lunch" hours. I could do that in my school district easily. Like a neighborhood watch type of thing.