when I lived in western Ohio (very, very few road cyclists), I'd have a problem with drivers refusing to pass over the double yellow about 1-2 times a month. Never had that problem in PA.

There's a stretch of road near my parent's house that I have to ride in order to reach the surrounding rural areas. It's a one lane each way stretch that's very narrow, uphill (going outwards), and fairly heavily trafficked with no places to pull off. By the time the road widens again, I usually have 4-5 cars behind me. I wouldn't choose the route over any other viable alternative, but its at least usable.