There is no other place the kids could ride those bikes in such a tiny town. There are no sidewalks, all the streets are one-lane, most with no shoulders.
Riding our bicycles was play behavior when I was a kid. Having said that, we realized we were sharing the roads with cars, so we did not do too many dumb things. Of course, we didn’t play checkers in the middle of the street. I think the story is about kids riding bikes in Charlotte, not about them setting up doll houses.