Rigid zoning requirements

A particular kind of "residential" zoning category rewards developers of large, economically segregated, monolithic residential subdivisions. It keeps their investments (and the homeowner's) stable. It unfortunately excludes the types of commercial developments that are needed by the average householder (e.g. food and convenience stores), so requiring the ownership and frequent use of motor vehicles for daily needs.

In the 1980s the number of vehicle miles travelled in the United States grew four times faster than the population did, largely due to the separation of residential and commercial areas making it impossible for most people to walk from their homes to their workplaces or to shops.