In the USA a nationwide grid of metropolitan areas with populations beyond the million mark has emerged. The strength of the national economy appears to be exhibited through those large agglomerations and the linkages that they have developed amongst themselves, other components of the national economy and in some instances elements external to that economy. Metropolitan areas in the size class referred to, and some not quite so large, are expanding their boundaries or spheres of influence in ways that signal changes for the urban areas in question and indeed for the national economy. The current discussion reviews and synthesizes recent thinking concerning urban peripheries and adjacent areas with an eye to understanding their role in a changing economic infrastructure. In keeping with advances in transportation and communications and the emergence of service industries, developments on the metropolitan peripheries are assisting with the ongoing functional linkages of their metropolitan hosts to the national economy and beyond, and thus are contributing to their continuing viability
