My road is narrow, yet two cars can still pass quite easily.. There is no center line, speed limit is 35mph (not one person follows it, even I have trouble), some areas are slightly uneven (but it's still completely paved).
I got pretty freaked out when I had to pass a cement truck in my 7ft wide van. I could feel the tires slipping on the road edge (and there is a ditch with trees on either side of the road).