ABSTRACT
Massive suburban development over the course of this century has given the newer North American cities a form which differs significantly from that of earlier cities. Forty-five per cent of the US metropolitan population today lives in areas that are called suburbs. The country's metropolitan housing stock is new. Only 20 per cent of it predates the 1920s, although this figure varies from more than 40 per cent in the North East to less than 10 per cent on the West Coast. Piecemeal development characterizes the newer parts of cities, with only 10 per cent of residential suburban development being in the form of planned communities. Since the 1920s, residential development has occurred within a loose framework of local land-use laws, regulating the subdivision of land and the distribution of functional elements, and of building codes. Both land-use laws and building regulations support a strong tendency towards the ownership of single-family houses and automobile transportation. Over time, they have favoured tremendous increases in the spread of metropolitan areas. Today, the urbanized area of Los Angeles covers 474,000 hectares (1,170,780 acres) and has a population of 9.5 million people. In comparison, London's urbanized area spreads over 120,000 hectares (296,400 acres) and has a population of 6.5 million people. London's gross density of 56 persons per hectare (22.7 per acre) contrasts with a gross density of 20 persons per hectare (8.1 per acre) in Los Angeles. Though several of its parts are considerably older than those of Los Angeles, the New York-New Jersey urbanized area has a gross density of only 21.5 persons per hectare (8.7 per acre) (Newman and Kenworthy 1989). Such sprawling cities have morphological characteristics that differ substantially from European cities (Whitehand 1987).
