This ties in rather closely with Chris Kulcyzski's diary on cars today, in so much as in America, at least, the same modernists who made it their mission to destroy livable architecture also made it their mission to destroy the density and diversity of the city.  Seeing such things as walking and street life as anachronisms of the past, they longed to create the perfect of world of complete residential/business/industrial segregation, of grid-like cities connected by highways with no sidewalks, where everything was in its place and everything was accessibly only by cars.

I've grew up in one of the earliest fruits of that vision, suburban Los Angeles, and am now live in a place that seems to have completely ignorged the urban-planning aspects of modernism, Japan.  I have to say, in a lot of ways Japan is a hell of a lot more liveable.