It is very dependent on the community and the school, but there’s plenty of schools that are absolutely deserted outside of school hours for a variety of reasons. Some schools have playgrounds or basketball hoops or the like but some don’t, or they’re locked up, so why would kids go that way instead of the park.

The risk has been identified as high population of children during certain hours crossing streets etc., and is mitigated by lowering speed limits during those hours. Whether it’s an accurate risk assessment is a good question though. Personally, I think the influx of drop-off traffic is worth mentioning, but who am I to say?