Flatfrog said:
The second point is that there is a simple solution, which is to change the law to allow cycling on the pavement with the following provisos (which are also my own personal code of conduct when cycling on a pavement myself):
1) A speed limit of, say, 10mph on any pavements with doorways that open directly onto them.
2) An absolute right of way of pedestrians over cyclists. If people are in your way, you have to wait. And no furious ringing of bells either.
3) An assumption of liability in the case of accident. Any unintentional collision between a cyclist and a pedestrian is automatically assumed to be the cyclist's fault.
This works so much better if we have pictures. I'll post a picture, and what I think makes sense regarding bicycling.
For this:
The primary people riding bicycles are going to be kids, and they SHOULD ride on the sidewalk, as it's far safer than the road, though for older bicyclists it really doesn't matter much since car speed is low.
For this, which is the main road just outside my neighborhood:
The speed limit is 45 mph here, and 55 mph just beyond here in both directions, so riding on the sidewalk is far, far safer than on the road, and only 'pro' bicyclists would even consider riding on the road. In California, the equivalent type of road tends to have very wide shoulders or dedicated bicyclist lanes, but anywhere that doesn't should ride on the sidewalk for safety.
I can't find a picture that would fit your first point, but outside of cities, it doesn't fit at all. In general, if you're in a city, use the damn bike line if there is one, but it should hardly matter, since everyone is going slow to begin with. If it's a road with a decent speed, unless you're a 'pro' bicyclist, just use the sidewalk, it's safer.