Infill is Standard Operating Procedure
"[I]nfill has been going on for years, along with suburbanization, both in the United States and in other first world nations. This is indicated by the general densification trend that occurred in US urban areas between 1990 and 2000 and the longer term densification trends that occurred in a number of southwestern urban areas, such as Los Angeles, San Jose, Riverside-San Bernardino, Phoenix, Dallas-Fort Worth and Las Vegas. All these traditionally 'sprawling' areas have, in fact, been densifying since 1960 or before. Since 2000, 33 of the nation's 37 urban areas with a population exceeding 1,000,000 population experienced population infill to their 2000 urban footprints."