[Endama]

A lot of it seems to exacerbated by limited access to quality public transport. As jobs become more consolidated in city centers, the middle and lower class are more likely to get priced out of living near their work places. High insurance and other private vehicle costs (tickets, maintenance, traffic) make car ownership impossible for mid/lower class citizens.

So you end up with a bunch of people, living in poor housing conditions, with poor access to quality transportation, which means the amount of time they are spending in transit, or the jobs that they can reasonably have access to, is constrained.

America should have spent more time trying to shift demand away from private car ownership and more towards effective public transportation. Doing so would make areas outside of major metropolitan areas available for middle/lower class people and allow smaller/mid sized cities benefit from the tax revenue.