It seems extremely plausible that American society fell in love with the automobile and went on a nation-wide car-friendly infrastructure building binge after WW2 before many of the downsides were well understood. Were the people selling suburban homes to people with G.I. Bill loans doing environmental impact assessments, calculating emergency services response times, and giving their customers projections for what the commute times would be in 10 years after all the houses were built and occupied? We didn't even know the right questions to be asking back then, let alone have quality data to answer them.