In the early stages of metropolitan growth, jobs tend to concentrate in downtown business districts, which are the focus of the metropolitan transportation system. Employers find it more profitable to locate at the urban center and bid up the price of land there. Residential uses move to the periphery of downtown where land is cheaper and eventually, if growth continues, to the suburbs. Initially, the suburbs are simply bedroom communities. But as growth continues, the commute from the suburbs to downtown becomes increasingly difficult.
Employment begins to move to the suburbs.
As a consequence, the ratio of jobs to housing tends to grow over time in the suburbs. This shift of jobs to the suburbs might be expected to reduce commute times. Many suburban workers are forced into long commutes because they are unable to find affordable housing near their jobs. Cervero identifies five forces that have contributed to these jobs-housing imbalances. Some suburban jurisdictions practice fiscal and exclusionary zoning .