I’m in general agreement with those who believe sidewalk riding is not a good idea. My belief is that the dangers associated with intersecting cross streets and driveways from a sidewalk will almost always offset anything gained by removing oneself from the traffic lane. On-street bike lanes, whether they be striped or separated by some low physical barrier, are a better bet because they place the rider in a position where they can be clearly seen by motorists turning across their path from either direction.
There are occasional exceptions though. Last evening, I took one of my dirt path alternate routes and ended up being dumped on the wrong side of a 4-lane parkway with a wide center median. My options were to either ride a quarter mile in the opposite direction, which would have been fine and normally advised, or take a “sidewalk” in the direction I was headed. I opted for the sidewalk.
As you can see in the photo, this sidewalk is probably not what most people think of as a sidewalk. In fact, it looks an awful lot like a bike path. A number of these types of sidewalks line the parkways that criss-cross our city. These parkways typically have 4 lanes, a wide center median, and generous landscaped buffers between the road and the sidewalks. The surrounding neighborhoods are designed to feed onto smaller arterials, so there are minimal driveways and cross streets feeding onto these larger roads. These sidewalks are sorely underused by pedestrians, and it’s legal to ride bicycles on them. In a very real sense, they’re a type of hybrid sidewalk/bike path. They’re the closest thing to separated bike lanes that we have in our area.
Of course, bicyclists riding on these hybrid paths are well-advised to use extreme caution where they cross roads and driveways. It’s not good enough to only look ahead; it’s absolutely imperative to look for a right hook coming from the rear as well. As a regular thing, I’d just as soon ride out on the main road in the striped bike lane where motorists can see me coming and going, but in a pinch, these sidewalk/paths are a workable alternative as long as they’re approached with the proper care and an awareness of the potential dangers at road crossings.