I live in a high density area and don't consider sidewalks very safe. Mainly because the many apartment/condo complexes have underground parking lots. When cars come out of the subterranean lots, not only are they completely blind on both sides, but the driveways' steep incline flattens out at the sidewalk. Since drivers don't like to stop on an incline, they come roaring out and 'hang' on the apex before looking around - in the case, right in the middle of the sidewalk. I know a few complexes have bubble mirrors, but 90% of them don't. It's an accident just waiting to happen.