Originally Posted by B. Carfree

Hmm, the ambient speed may be 10 mph due to overcrowding by motorists. Under those conditions, the typical motorist is just fine with that speed even on roads posted for 65 mph maximums. However, let these same people find themselves behind a cyclist travelling at 15 mph for a few seconds and you don't think they can be trained to not go into a homicidal rage?

Sorry for the culture you find yourself living in. I've lived in regions of the US where people have been civilized enough that they could handle such things without risking people's lives, so I know it is possible. We don't need massive amounts of concrete for partial segregationist infrastructure (which still requires vigorous law enforcement to deal with those lousy intersections), we just need proper law enforcement or a large enough shock to change the culture. The student loan debt bomb may well be that shock and every thing else may just be details.