Thomson* notes an inverse relation between the number of center city jobs and the number commuting by car. The implications of Thomson's data are significant because of it's age. Most of it is drawn from 1963 and 1973. Detroit had only 80 thousand jobs (Thomson 35). That makes some of the 'center cities' of Thomson's age are equivalent in size to Garreau's 'Edge Cities' of today. Automotive sprawl had become the dominant land use pattern by 1970, and the public tram-ways were long since replaced by buses. Yet the relationship remained...the question remains--is it a matter of share of total regional jobs, or merely the geographic concentration of jobs?
*Thomson, Michael, J. Great Cities and Their Traffic. London: Victor Gollancz ltd. 1977