The 213 urban areas in 1960 were tentatively segregated into four population size groups and were subdivided, based on population density, into three density classes for each size group. Automobile availability and mode of transport used in the work trip were rated primarily as functions of population size and density. Population density, however, was found inadequate to explain urban area variations in most of the selected indicators of transportation and socioeconomic characteristics. The interrelation between 6 dependent transportation variables and 12 independent socioeconomic variables in each of the four population size groups was analysed using step-wise multiple regression regression procedure. Several of the equations developed may be used to estimate indicators of auto availability and travel characteristics. Urbanized areas were regrouped in terms of the ratio of available cars to employed persons. The resulting urban area types in each size group displayed transportation, socioeconomic, and geographical characteristics. Further testing of this typology as a basis for microanalysis of travel characteristics of an area type was recommended.
Abstract