I've been riding on the right side of a rather narrow road that has one lane in each direction plus cars parked along the edges (but not enough room to pass a bike safely). Sometimes cars passing me make dangerous swerves into the other lane and almost hit oncoming cars -- I think they don't realize I'm going 17-20mph and that they really need to gun it and cover some ground before they're past me. It's kind of a no-win situation for me and the cars. I want them to be able to pass me and get back up to 35mph, but I ain't gonna get doored for their convenience. The good thing is, I can avoid that road on my route, so I usually do.