Other authors are developing physical planning and urban design strategies for the metropolitan region. Foremost among these are Peter Calthorpe and William Fulton, whose book The Regional City: Planning for the End of Sprawl seeks to define regional design as a legitimate field of inquiry.

The words "regional planning" appear in the titles of many academic planning departments. However, there is very little consensus about what the term "regional" means or what the agenda of the regional specialty should be. This is not a new problem, but it is one that very much needs to be addressed, as the rapid physical evolution of urban regions in the twenty-first century presents ever greater challenges in terms of livability, sustainability, and equity.

The recent upsurge of interest in metropolitan regionalism-catalyzed by concerns about growth management, ecological sustainability, and suburban-central city equity disparities and found in the writings of Peter Calthorpe, Anthony Downs, Myron Orfield, Douglas Porter, and David Rusk--often focuses on the question of how planners can help create a more compact, transit-oriented metropolis. To many this seems to set an impossible goal. Indeed, a few observers such as Peter GordoJ:i and Haryr Richardson even argue that compact development is not necessary, believing that plenty of land and resources exist for suburban development and that traffic and efficiency problems are benign. A much larger number of planners believe that suburban sprawl does jeopardize equity, environmental, and even economic objectives, but have little hope of changing current land use and transportation patterns anytime soon.

Built landscapes—patterns of streets, blocks, parcels of land, buildings, and related infrastructure at the scale of an urban neighborhood or greater—are often difficult for decision makers and the public to understand, especially within the complex “collage city” of the postmodern era. Yet understanding the variety of these forms can help stakeholders make wise choices regard- ing how to plan and design urban regions in the future to meet goals such as livability and sustainability. Based on aerials, maps, and images available through Google and other sources, I develop a typology of built landscape forms found within 24 metropoli- tan regions worldwide and use GIS to map these forms and compare regions. The analysis shows that 27 basic types of built landscape make up metropolitan regions worldwide, of which nine are very common. Traditional urban types now make up a small fraction of most metropolitan areas world- wide, while suburban and exurban forms comprise the vast majority of the land area. There are noted regional differences in the mix of built landscape types.

Takeaway for practice: Each built landscape form offers challenges and opportunities for planning objectives such as livability and sustainability. It is important for planners to a) help the public and decision makers understand built landscapes and their implications; b) include landscape-scale elements, such as street patterns and networks of green infrastructure, when framing urban development alternatives; c) ensure that local codes and design guidelines enable desired forms of built landscapes and discourage those that are problematic for sustainability; and d) encourage built landscape change that promotes sustainability.