A highway that encircles a metropolitan area and provides access to outlying suburban areas as well as a bypass around the central urban area; also called a loop, perimeter, or circumferential highway.
A metropolitan area is generally a developed region that is economically attached to a large central city, encompassing towns, suburbs, and other peripheral areas.
A Primary Metropolitan Statistical Area (PMSA) is a geographic entity designated by the federal Office of Management and Budget for use by federal statistical agencies. It is a subunit of a larger metropolitan area that has a census population of one million or more.
