University of California Transportation Center

Land use patterns and its change lie at the heart of modern theories of urban spatial structure, as land use deals essentially with the spatial aspects of all human activities on land and the way in which the earth's surface is adapted, or could be adapted, to serve human needs. People's print on land is most evident in metropolitan regions, which, in the US case, now house 75% of the whole population with only 1.5% of the country's land. In terms of land use, these are certainly the most complicated areas on earth, as the surface of this small but critical part of the earth is almost completely formed by human activities. As physical expression of human relationships with land, the spatial juxtaposition of different land uses also tells much about the relationships between people. The inquiry into the characteristics of the internal organization of metropolitan land use, however, is not merely an academic matter, observed more than half a decade ago by Homer Hoyt (1939). In the current context of metropolitan growth, the intense policy debates over zoning, growth management, infrastructure investment, environmental preservation, social justice and life quality improvement all depend upon the forces governing the spatial interrelationship of different types of areas and the past and prospective movements of different types of uses.