I've always suspected that one of the driving forces of the expolsion of the suburbs in post war america was due to atomic weapons. This picture, if true to scale, reminds me of that. Older cities could be easily wiped out in ww3. Atlanta, which saw a huge amount of growth in the second half of the twentieth century, would be harder to completely destroy.

I've never really seen evidence that there was a real effort to spread out cities due to the cold war. Most histories of suburbia focus on white flight and yhe automobile.