Extended and Internal Commuting in the Transformation of the Intermetropolitan Periphery

Abstract

This paper assesses the roles played by extended and internal commuting in urbanizing the intermetropolitan periphery by studying 4 standard metropolitan statistical areas (SMSAs) in northeast Georgia (GA) and adjacent South Carolina (SC). Extended commuting is worker movements across county boundaries from nonmetropolitan areas to metropolitan areas. Internal commuting is worker movements such that origin and destination counties both lie within the intermetropolitan periphery. In the US, nonmetropolitan population growth rates now exceed those of metropolitan areas. 2 frequent interpretations of this trend are that nonmetropolitan growth is 1) decentralized resulting from metropolitan spread and 2) partially independent of metropolitian influence. The study uses commuting destinations from the 4 SMSAs (Atlanta, Macon, and Augusta, GA, and Greenville, SC), their respective central cities, and selected internal or intervening opportunity centers within the intermetropolitan periphery. Extended commuting fields were identified for both 1960 and 1970 using 0, 5, and 10% isolines; this paper only includes 0 and 5% isolines. There is an modest expansion of the 5% lines by 1970 for each region, indicating the extension of metropolitan influence. Growth is most apparent in larger centers such as Gainseville, Athens, and Conyers. By 1970, the 5% isolines show extreme cases of overlapping commuting fields. Residents of such zones interact significantly with more than 1 center; therefore, urbanization of the intermetropolitan area occurs both in response to metropolitan spread and the internal growth processes extending the influence of internal centers. Population growth within this nonmetropolitan area is linked to metropolitan center expansion and commuting to smaller internal growth centers plays an equally important role. 76% of county divisions within 15 miles of a metropolitan or internal growth center and 48% at distances of 15-35 miles experienced population increases over 5% from 1960-1970; 74% outside of 35 miles experienced losses exceeding 5%. Thus, nonmetropolitan growth is more than just spread of metropolitan areas into nonmetropolitan areas. The proximity of the internal centers and the increasing overlap of commuter fields supports the convergence of an urban system in which the smaller urban centers become integrated through a set of horizontal linkages. Nonmetropolitan growth may reflect the emergence of such a system.