What the heck does land use have to do with sustainable transportation?

I’m glad you asked.

Put simply, the less you have to rely on mechanized transportation, and the shorter the distances are that you have to travel, the more sustainable a city will be.

Modern cities are an unprecedented phenomenon in regard to the location of activities and the distances that separate them. This phenomenon was made possible by mechanized transportation, and since World War II has become systemized and institutionalized in the financing, construction, and planning of cities, creating the phenomenon of urban sprawl.

If jobs, stores, services, schools, and public spaces are co-located with housing, more people can work, shop, get educated, obtain services, and socialize close to home. When neighborhoods consist of homogeneous tracts of single-family homes, with goods and services isolated as islands in the middle of parking lots, very little of daily life can be carried out without utilizing some form of mechanized transportation. It’s not to say that mechanized transportation should never be used – on the contrary, it is essential. But such transportation can only be sustainable when it can be effectively served by bicycle or mass transit for the majority of trips between neighborhoods. And that requires that neighborhoods not only be walkable, but connectible.

Making and operating buildings are 39 percent of our carbon emissions, and what is transportation? Driving between buildings. What is industry doing? Mostly building cars and transportation infrastructure. They are all the same thing in different languages, interconnected; you can’t have one without the other. To build a sustainable society we have to think about them all together – the materials we use, what we build, where we build, and how we get between it all.

Jarrett Walker

Transit consultant and author: Human Transit

Cities, towns, and villages weren’t built like this until the 20^th century. If you have ever visited a town or city that developed long before the automobile, you know what it feels like, and how different it is from most of our existing neighborhoods. Such places developed incrementally, with a form that fit the capacity for people to get around – primarily on foot. Houses tend to be close together, and often above shops and services. Living and working spaces are mixed together on the same street, and often in the same building. Destinations are mostly in close proximity and neighborhoods can be easily traversed on foot. Public spaces – squares, parks, fountains, tree-lined walkways or even just a water well with a patio around it – are numerous and serve as focal points of community activity. And if you arrived at these places in a car, you may have found parking scarce, some streets designated as pedestrian-only, and perhaps some not even wide enough for a vehicle.

As automobile ownership expanded in an era of cheap fossil fuels, cities expanded with the automobile’s wider reach. Land speculation and industrial-scale housing construction created whole urban landscapes almost entirely of detached residential buildings, and more area was dedicated to automobiles to accommodate this growth, with as much as 60% of the land area of some cities dedicated to streets and parking lots. New roads, highways, and utility infrastructure built to serve these new neighborhoods extended the reach to even further areas of low-density development. Commercial and institutional development that served these newly spreading populations was typically located in large clumps designed to accommodate the automobiles that both became necessary to reach these new neighborhoods and in a self-reinforcing cycle created the necessity to accommodate them with even more roadways and parking lots. These new urban spaces presented some problematic but mostly unintended consequences: high cost of infrastructure and utility services per inhabitant, increased consumption of water, energy, and materials, increased stormwater runoff, increased air and water pollution, economic inequity, high dependence on automotive transportation, loss of community cohesion, longer commutes, and increased traffic congestion.

The proliferation of automobiles made necessary by the dispersed pattern of land use naturally resulted in some roadways experiencing more and more congestion. The response to this for decades was to try to provide additional roadway capacity. But this response does not actually lessen congestion, it just enables the congestion to expand or spread to new areas. This pattern of development, commonly known as urban sprawl, was created in part to preserve racial segregation and reject the growing diversity of older city centers. Sprawl did not evolve incrementally, but was built in major surges of investment for quick sale of land and buildings. Despite their initial attraction, these areas of sprawl are prone to fairly rapid degradation of physical infrastructure and economic viability. Urban sprawl also has a negative effect on public health, as walking to a destination became impractical, air pollution afflicted lungs and eyes and skin, and vast acreages of pavement limited the presence of beneficial vegetation and caused temperatures in urban areas to exceed surrounding rural areas by as much as 22° F, making walking or bicycling less attractive and adding to air conditioning energy use. On top of all this, the effects of burning fossil fuels on the global climate has brought into focus the need to reduce transportation energy use.

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If you plan cities for cars and traffic, you get cars and traffic. If you plan for people and places, you get people and places.

Fred Kent

Project for Public Spaces

Sprawl imposes significant social, economic, environmental, and health costs. It is unsustainable on a number of counts, including the financial unsustainability of the infrastructure required to support acres of roadways and parking space (with the average car parked for 95% of its lifetime) and miles of utility services to connect acres of low-density residential development with distant acres of goods and services. Virtually every municipality in the USA is facing a growing backlog of “deferred maintenance” – street, curb, water, stormwater, and sewage infrastructure that is deteriorating but that tax revenues are insufficient to repair or replace.

Reducing the demand for motorized mobility is a critical element in improving sustainability. Our cities are characterized by low-density sprawl and zoning laws that limit the proximity of housing, employment centers, commerce, and services. Our pattern of land use is intrinsically tied to how far we have to travel and what type of transportation is practical to use. Reimagining land use opens the door not only to more sustainable transportation, but also to healthier and more pleasant neighborhoods and better conditions for local businesses to thrive.