Urban sprawl is an intrinsic dimension of urbanization, which underlies the processes of spatial diffusion occurring in most developed countries.

As modern cities become more complex also the phenomena of urban sprawl become increasingly faceted and diversified. One major aspect of novelty in the current trends is that sprawl does not only affect the use of land but has also an impact on the social, functional and economic spheres of urban life. It may also extend on different spatial levels, affecting not only cities and their surrounding areas but also whole metropolitan regions.

Although the phenomena of urban sprawl are specific of the urbanization and policy history of each country, in all situations, there is a mounting evidence that their consequences bear increasing economic, social and environmental costs which are major issues for the sustainability of our cities.

In Britain the policy of urban containment has been implemented for more than fifty years. Today centrifugal tendencies are at work, which involve both people and jobs, within and between main urban regions. In spite of its longstanding experience in dealing with urban sprawl, Britain seems to be locked to its traditional responses of urban containment It is now facing a new urban-development challenge which require a kind of strategic thinking such as those which characterised the policy responses more than half a century ago.

Tony Champion is Professor of Population Geography at the University of Newcastle upon Tyne in north-east England. His research interests include urban and regional changes in population distribution and composition, with particular reference to counterurbanization and population deconcentration in developed countries and the policy implications of changes in local population profiles. He is chair of the IUSSP's Working Group on Urbanization and is also Director of Newcastle University's Housing and Society Research Group. He is author or co-author of several books and reports including Urban Exodus (1998), The Population of Britain in the 1990s (1996), and Counterurbanization (1989). Over the last three years he has carried out research for the UK's Department of Transport, Local Government and the Regions, the Council for the Protection of Rural England, the Housing Corporation, and the Council of Mortgage Lenders.