I pass several K-12 schools on my commute, so most of them are children on the sidewalk. Probably 5-10 on a nice day. I've only seen one of them actually in the bike lane--I'm not sure if the "no sidewalk riding" rule should apply to these kids? They are definitely not steady in their riding or completely spatially aware, but some of the sidewalk paths are pretty treacherous too.

Concerning adults, most of them in the residential areas seem more like recreational riders, mostly because they are of retirement age and don't seem like they're in a hurry. The only adult commuters I see on a regular basis (maybe 1-3 a day) is in the last bit of industrial stretch of my commute, and most of them are in casual clothes on mountain or hybrid bikes.