It means heavy car dependence unless you expect people to change careers when they have a family. Hence the modern American cityscape, with most the population spread out amongst suburbs.
A lot of the jobs are in the suburbs (finance being something of an exception). A lot of the tech industry is in car-reliant suburbs. I live in Massachusetts and, until west coast firms established outposts in Boston/Cambridge and pharma basically took over Kendall Square, there was basically no tech industry in Boston for a couple decades.
And, yes, outside of Manhattan and young people essentially living like they did in college for a few years, car dependency is just what most people do.
