What makes an urban landscape sustainable?

The urban sprawl that has characterized most development in the last 80 years has resulted in cities and towns with fiscally unsustainable infrastructure, buildings that have enormous appetites for energy, water and materials, employment locations that demand motorized commutes for almost all employees, and almost total dependence on automobile transportation for even the most mundane of tasks, like going to school, buying groceries, accessing services, or participating in civic life. While most communities proceed with “business as usual” despite these issues, the fact remains that this is not sustainable.

Fortunately, examples of more sustainable urban landscapes are abundant – in every urban landscape and rural town center that is more than 150 years old. These spaces evolved around human-scaled mobility – primarily walking.

“The average car is 80% empty when driven, and is parked 95% of the time. Ownership is expensive. Less than half of all trips are by driving, yet road space is almost entirely prioritized for cars. This represents an incredibly inefficient use of resources and makes it difficult for those who can’t afford or can’t drive to access the city.”

San Francisco Metropolitan Transportation Agency

Meeting the Smart City Challenge

In attempting to address the fiscal, environmental, and social challenges created by auto-centric cityscapes, engaged citizens, civic leaders, and many members of the planning profession looked at still-thriving historical cities, villages and town centers and came up with some new/old ideas. Terms that have been used for these concepts include urban villages, transit-oriented development, and walkable communities. A term that has emerged to encompass these ideas as a whole is New Urbanism.

Generally the principles of New Urbanism include the following:

Higher-density urban centers or “nodes” around which lower-density development spreads in decreasing density along transportation routes. The “urban transect” is a concept that develops this idea further. These higher densities typically consist of buildings in town or city centers that share a common frontage, with most buildings adjoining others on both sides, and building height in proportion to the size of the population. Further from the city center densities consist of a mixture of single-family homes, duplexes/triplexes/”4-plexes”, and apartment buildings, and smaller businesses, such as corner stores and medical offices. Only in the largest of cities are high-rise residential buildings a component of these higher urban core densities.
Mixed uses, with residential, retail, services, and workplaces all within the same neighborhood, with commercial and institutional spaces serving and, to a large extent, employing local residents. Rather than zoning for function, areas are zoned for density, shape, and intensity of infrastructure services, with mixed uses encouraged or even required. For example, all ground floor spaces on principal street frontage might be commercial, with upper floors for professional offices and/or residential, and residential occupancies intermixed with commercial on the same block.

Walkable neighborhoods, with wider sidewalks, buffers between pedestrians and vehicle traffic, “complete streets” that accommodate pedestrians and bicycles as well as cars, and more or larger public areas with greater density and services. Instead of designing for maximum automobile access, neighborhoods are designed for ease of pedestrian and bicycle access, often with limited parking that is located behind, rather than in front of, stores and businesses. Walkable neighborhoods typically have public spaces conducive to social contact, such as extra-wide sidewalks to accommodate outdoor seating in front of restaurants and cafes, landscaped areas with places to sit, and public plazas where performances and civic events take place. Walkable neighborhoods prioritize pedestrians, so the number of driveways in a block may be limited, streets may be designed to limit practical speeds of traffic, and most traffic may be routed to the periphery of urban cores.

Integration with public transit, with higher-density nodes interconnected with other nodes along transit routes, transit stops designed into public spaces, and convenient stops between nodes to provide access from outlying areas.

In addition to the above, the Congress for New Urbanism promotes the principle that urban places should be framed by architecture and landscape design that celebrate local history, climate, ecology, and traditional building practices.

These new urbanist concepts are slowly being put into practice in cities all over the United States and the world. They are proving to be quite popular – raising property values, revitalizing neighborhoods, enhancing public spaces, achieving higher densities, presenting new local economic development and employment opportunities with decreased commute times and a better quality of life.

The urban sprawl that has characterized most development in the United States since the end of World War II turns out to be too expensive to expand or maintain, too energy-intensive, too hard to get around in, and lacking in the very amenities that urban life was supposed to bring. New Urbanism principles and practices offer solutions that can be applied to make both new and existing urban spaces more sustainable.

Walkability is much more than a trend. For thousands of years, creating cities has been about proximity. Even with all of the leaps within transportation and technology, I believe that this remains true. The best places to live in the world have everything within walking distance. It is still the most important form of transportation because every trip begins and ends with walking. We made a big mistake when we thought cars were the future, and started designing cities for them. The future of cities should be about simply prioritizing the street for walking because it is something we all do.

David Sim

Creative Director, Gehl Architects