As defined for the 1980 census , urban areas ( a ) places of 2,500 or more inhabitants incorporated as cities , villages , boroughs ( except Alaska and New York ) and towns ( except in the New England states , New York and Wisconsin ) , but excludes those persons living in the rural portions of extended cities ; ( b ) census designated places of 2,500 or more inhabitants ; and ( c ) other areas , incorporated or unincorporated , included in urbanized areas .
Urban areas have more than 2,500 residents and underground utilities .