Originally Posted by
noisebeam
And if not a vehicle or a horse, what else can legally use the roadway? (Pedestrians of course, but only for very specific non-vehicular cases.)
It's not clear, and the cops aren't sure either. The article suggests pedestrian.
Here's CA pedestrian law. It kind of assumes pedestrians walk on sidewalks. There are a few references to "walking," though the definition mentions wheelchairs. As long as he's yielding to cars, he may be completely legal.