Classic suburbia was desirable because it promised living in a newer house with a private yard and a garage, on a low-traffic street, in an ethnically and socio

Classic suburbia was desirable because it promised living in a newer house with a private yard and a garage, on a low-traffic street, in an ethnically and socioeconomically homogenous neighborhood zoned to a well-performing school. Automobile dependence was a feature to empower the car-owning suburbanite and to restrict the casual exfiltration of people from the city into the suburbs. (These fears, that good-for-nothings will take public transit to cause trouble in the suburbs crop up to this day.) As suburbs age, their advantages decline. The houses are no longer new, traffic (on all but the leaf-node cul-de-sacs) has increased. When one suburb is built out, the urban area spreads outward, and newer suburbs and exurbs are created. Those that can afford to move do so, slowly decreasing the average income of the neighborhood, which correlates strongly with school performance. Desirability keeps declining in turn. Some suburbs can avoid this fate by becoming large employment centers, and then we call them edge cities instead (e.g. Irvine, Tysons, Bloomington).