If you have a road outside the city that actually has something resembling a sidewalk, yeah, might be best to ride on there. I was thinking more of towns or suburbs that have the road and then the sidewalk alongside it, though. And of course it depends on what the speed limit on the road is, and what kind of traffic there is - only a madman would go biking on a road with a speed limit of, say, 50 (I'm not much of an expert in speed limits, especially in mph in the US ).