In the post-industrial era, an edge city is

In the post-industrial era, an edge city is a concentration of businesses, shopping and entertainment outside a traditional downtown in a location which had either been residential or rural. These were cities that often developed near airports, as many airports developed outside of city centers but close enough to have ease of access for people coming in and coming out. Examples of an edge city are Tysons Corner, Virginia (lies next to Washington, DC) and Detroit's New Center, which was within Detroit's city limits, but away from downtown.