Polycentric metropolitan area

Definition

There has been no significant change in the basic concept of metropolitan areas since its adoption in 1950, although significant changes in geographic distributions have occurred since then, and more are expected. Because of the fluidity of the term "metropolitan statistical area", the term used colloquially is more often "metro service area", "metro area", or "MSA", taken to include not only a city but also the surrounding suburban, exurban and sometimes rural areas, all of which the city is presumed to influence. A polycentric metropolitan area contains multiple urban agglomerations not connected by continuous development. In defining a metropolitan area, it is sufficient that a city or cities form a nucleus with which other areas have a high degree of integration.