Peter Calthorpe and The Next American Metropolis: The Origin of TOD

The Next American Metropolis: Ecology, Community, and the American Dream (1993) is the book in which the architect and planner Peter Calthorpe formulated transit-oriented development, the model that proposes concentrating housing, jobs and shops in walkable neighbourhoods around public transport stations as an alternative to the dispersed suburb. Calthorpe, co-founder that same year of the Congress for the New Urbanism, argued that the postwar American metropolis, made of isolated subdivisions, shopping malls and highways, had exhausted its capacity to produce community, protect the environment and offer the American dream to anyone without two cars.

Three crises of the suburban metropolis

The diagnosis rests on three crises. The ecological one: suburbia consumes farmland, fragments habitats and generates emissions with every compulsory car trip. The social one: the separation of uses and housing types isolates older people, the young and single-income families, and removes the spaces where neighbours meet. And that of the American dream itself: the single-family house with a garden, affordable in the 1950s, had become a privilege demanding ever more miles and more debt. Calthorpe does not propose abandoning the suburb but remaking it with the tools of traditional urbanism.

Transit-oriented development: design principles

The central proposal is transit-oriented development, an evolution of the pedestrian pockets Calthorpe had put forward in the late 1980s. A neighbourhood of walkable radius, about 600 metres, around a rail or bus rapid transit station, with a commercial and civic core, medium densities decreasing toward the edges, a mix of housing types for different incomes and ages, connected grid streets instead of cul-de-sacs, and public space, squares and parks, at the centre. The book includes design guidelines that became a manual for municipalities and developers across the United States.

The regional scale: Portland, Laguna West and The Regional City

Calthorpe insisted on the regional scale. A single transit-oriented neighbourhood isolated in a sea of suburbia changes nothing; what is needed is a network of such neighbourhoods linked by public transport and surrounded by protected land. His work with the Portland region on the 2040 plan and later in The Regional City (2001) with William Fulton developed that idea: urban growth boundaries, transit corridors and a hierarchy of centres. His projects, such as Laguna West in Sacramento, also showed the limits: without the promised public transport, the walkable neighbourhood ended up as car-dependent as its neighbours.

Influence, critiques and Calthorpe's legacy

The book's influence has been enormous. Transit-oriented development is now official policy in dozens of US metropolitan regions and in cities around the world, from Copenhagen to Curitiba, and Robert Cervero's research confirmed that its principles, density, diversity and design around stations, reduce car use. Criticism has grown too: many projects labelled transit-oriented are luxury developments beside a station that gentrify the neighbourhood and push out the regular users of public transport, and New Urbanism has been accused of producing aesthetic imitations of the traditional city without its diversity.

Calthorpe answered those critiques in Urbanism in the Age of Climate Change (2011), where he showed with data that compact urban form cuts emissions more than any technology, and in his later work on bus rapid transit corridors and affordable housing. His legacy is to have turned an idea, building the metropolis around transit and the pedestrian instead of the car, into an applicable method, and to have shown that suburbia was not an inevitable destiny but a design decision that could be taken differently.