The relationship between motorists and bicyclists in major American cities is, er, “complicated,” as the euphemism has it. Most U.S. cities lack any real bike infrastructure—think distinct, separated lanes, like in Amsterdam and Copenhagen—which means that cars and cyclists are forced in most cases to share the road. (No, painting the image of a bicycle on the pavement—a so called “sharrow“—does not a true bike lane make.) Couple that with many bikers’ well-documented tendency to flout the rules of the road, at least when it suits them, and you have a combustible mix.