here in california, it's illegal to ride a bike on the sidewalk. We have bike lanes along the roads, but even without those, you can not ride on the sidewalk.
They do seem to make an exception for young children riding their bikes on the sidewalks, but other than that, you get a ticket. The law is cars and bike have to share the road, the side walks are for people walking only.
That's just california anyway, and yes we are a weird state I know LOL