It is legally difficult to build good urban places in the United States. The vast majority of conventional zoning codes prohibit the replication of our best examples of urbanism--places like Nantucket, Williamsburg, or even "Main Street U.S.A." in Disneyland. This situation has been profoundly damaging. Our current codes are based on a theory of urbanism that is decidedly anti-urban. They separate land uses, decrease densities, and increase the amount of land devoted to car travel, prohibiting the kind of urbanism that typifies our most beloved urban places.
Ironically, by being anti-urban, conventional codes are also anti-environment. Through separation, districting, and rigid statistical procedure, zoning has forced us to think in terms of separating the human habitat from the natural one when they are really co-dependent. The natural environment is better protected when cities are viable places for humans to live. Conventional zoning, however fails to recognize this reality by prohibiting true urbanism and substituting it with the "anti-city" (1)--a landscape composed of monofunctional, single-use zones. True urbanism is diverse, compact, pedestrian, and celebratory of the public realm. Conventional zoning gives us only a disaggregated version of urbanism, commonly known as sprawl, which does not constitute a viable human habitat.
What is needed is a fundamentally different vision of how cities should be coded. This article lays out an example of a completely new genre of urban planning code--the Smart Code. (2) The Smart Code exemplifies how the principles of urbanism and environmentalism can be mutually protected and enhanced. It is strongly aligned with the notion of "smart growth," a planning and environmentalist movement based on the goals of environmental protection and sustainable development. (3)
The Smart Code is based on an explicit, normative theory, known as the Transect, that links human and natural environments in one conceptually continuous system. (4) The Transect concept promotes an urban pattern that is sustainable, coherent in design, and composed of an array of livable, humane environments. (5) Its principles are aligned with those of ecological and regional planners and urban theorists who have called for the need for a more enlightened approach to our current methods of urban expansion and regulation. (6)
I. SMART GROWTH CONCEPTS
Principles of smart growth, sustainable development, and New Urbanism have dominated discussions about urban form and sprawl in the last decade. (7) In its call for compact development, mixed use, and public transit, smart growth has naturally allied with a number of movements: historic preservation, downtown redevelopment, environmentalism, visual quality, public transit, bicycling, and pedestrianism. (8)
The need for smart growth extends beyond the bounds of urban planning practice. The problem of urban deconcentration has been expounded by environmentalists, (9) as well as economists. (10) Both groups are now intimately involved in exposing the liabilities of current urban growth patterns. Environmentalists speak of the need to reduce the ecological footprint of cities, whereas economists speak in terms of rectifying externalities and social costs. In either case, the objectives are fundamentally the same.
Many authors have focused on designing specific solutions to these consolidated views. They have addressed the need for compact, walkable urban areas with mixed uses that re-invigorate the public realm; lessen reliance on auto use; enable public transit; and socially, culturally, and economically integrate regions. (11)
Smart growth principles address two related problems: spatial separation of land use and lack of mobility. Remedies for the problem of spatial separation include mixing land uses and creating diverse environments similar to traditional, older cities. …