Residual space, as it exists today in the form of vast tracts of underused parking lots, derelict urban sites, obsolete industrial wastelands, and similar environments, is a relatively recent urban phenomenon. Alan Berger describes this fact in Drosscapes: Wasting Land in Urban America (Berger 2006), as he follows the creation of wasteland as a natural result of modern urbanization and the complex interaction of social, technological, and economic processes that drive contemporary urban growth.