Abstract
Urban sprawl is an increasingly common feature of the built environment in the United States and other industrialized nations. Although there is considerable evidence that urban sprawl has adverse affects on public health and the environment, policy frameworks designed to combat sprawl—such as smart growth—have proven to be controversial, making implementation difficult.
Smart growth has generated considerable controversy because stakeholders affected by urban planning policies have conflicting interests and divergent moral and political viewpoints. In some of these situations, deliberative democracy—an approach to resolving controversial public-policy questions that emphasizes open, deliberative debate among the affected parties as an alternative to voting—would be a fair and effective way to resolve urban-planning issues.
IN THE LAST TWO DECADES, public health researchers have demonstrated how the built environment—homes, roads, neighborhoods, workplaces, and other structures and spaces created or modified by people—can affect human health adversely.1–7 Urban sprawl, a pattern of uncontrolled development around the periphery of a city, is an increasingly common feature of the built environment in the United States and other industrialized nations.8 Although there is considerable evidence that urban sprawl has adverse environmental impacts and contributes to a variety of health problems—including obesity, diabetes, cardiovascular disease, and respiratory disease9—implementation of policies designed to combat sprawl, such as smart growth, has proven to be difficult.10–17 One of the main difficulties obstructing the implementation of smart-growth policies is the considerable controversy these policies generate. Such controversy is understandable, given the fact that the stakeholders affected by urban-planning policies have conflicting interests and divergent moral and political viewpoints.18 In some of these situations, deliberative democracy—an approach to resolving controversial public-policy questions that emphasizes open, deliberative debate among the affected parties as an alternative to voting—would be a fair and effective way to resolve urban-planning issues.
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URBAN SPRAWL
Urban sprawl in the United States has its origins in the flight to the suburbs that began in the 1950s. People wanted to live outside of city centers to avoid traffic, noise, crime, and other problems, and to have homes with more square footage and yard space.8,9 As suburban areas developed, cities expanded in geographic size faster than they grew in population. This trend has produced large metropolitan areas with low population densities, interconnected by roads. Residents of sprawling cities tend to live in single-family homes and commute to work, school, or other activities by automobile.8,9 People who live in large metropolitan areas often find it difficult to travel even short distances without using an automobile, because of the remoteness of residential areas and inadequate availability of mass transit, walkways, or bike paths. In 2002, the 10 worst US metropolitan areas for sprawl were Riverside–San Bernardino, CA; Greensboro–Winston-Salem–High Point, NC; Raleigh–Durham, NC; Atlanta, GA; Greenville–Spartanburg, SC; West Palm Beach–Boca Raton–Delray Beach, FL; Bridgeport–Stamford–Norwalk–Danbury, CT; Knoxville, TN; Oxnard–Ventura, CA; and Fort Worth–Arlington, TX.8
There is substantial evidence that urban sprawl has negative effects on human health and the environment.4,7,9,19 An urban development pattern that necessitates automobile use will produce more air pollutants, such as ozone and airborne particulates, than a pattern that includes alternatives to automotive transportation. The relationship between air pollution and respiratory problems, such as asthma and lung cancer, is well documented.4 Cities built around automobile use also provide fewer opportunities to exercise than cities that make it easy for people to walk or bike to school, work, or other activities.4 Exercise has been shown to be crucial to many different aspects of health, such as weight control, cardiovascular function, stress management, and so on.20,21
Because socioeconomically disadvantaged people in sprawling cities may have less access to exercise opportunities and healthy food than do wealthier people, sprawl may also contribute to health inequalities.22 Urban sprawl can reduce water quality by increasing the amount of surface runoff, which channels oil and other pollutants into streams and rivers.4 Poor water quality is associated with a variety of negative health outcomes, including diseases of the gastrointestinal tract, kidney disease, and cancer.23 In addition to air and water pollution, adverse environmental impacts of sprawl include deforestation and disruption of wildlife habitat.4
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SMART GROWTH
Many public health advocates have recommended smart growth as a potential solution to the problem of urban sprawl.4,7,9,20 Smart growth can be defined as a policy framework that promotes an urban development pattern characterized by high population density, walkable and bikeable neighborhoods, preserved green spaces, mixed-use development (i.e., development projects that include both residential and commercial uses), available mass transit, and limited road construction.4,7,11 Smart growth was originally conceptualized as an aesthetically pleasing alternative to urban sprawl that would offer residents a high quality of life and the convenience of local amenities,24 but it also has many potential health benefits, such as diminished air pollution, fewer motor vehicle accidents, lower pedestrian mortality, and increased physical exercise.4,7 Smart growth is different from the concept of “garden suburbs” because it addresses issues of population density and transportation, not just availability of green space and preservation of agricultural land.4
In the 1970s, Portland, Oregon, was the first major city in the United States to establish smart-growth urban planning by limiting urban growth to an area around the inner city.11 Since the 1990s, many other urban areas have encouraged the development of planned communities in which people can live, shop, work, go to school, worship, and recreate without having to travel great distances by automobile. An example of one of these planned communities is Southern Village, situated on 300 acres south of Chapel Hill, North Carolina. Launched in 1996, Southern Village features apartments, townhouses, single-family homes, and a conveniently located town center with a grocery store, restaurants, shops, a movie theater, a dry cleaner, common areas, offices, health care services, a farmer's market, a day-care center, an elementary school, and a church. Southern Village is a walkable community with sidewalks on both sides of the streets and a 1.3-mile greenway running through the middle of town. Southern Village residents have access to mass transit via Chapel Hill's bus system and can enjoy free outdoor concerts in the common areas. More than 3000 people live in Southern Village.25
Urban sprawl has occurred largely because land owners and developers have made choices that promote their own economic and personal interests, which do not necessarily coincide with the public good.18.25 Many community leaders have found it necessary to engage in centralized urban planning to promote smart growth.11 Various laws and regulations can help to control land use and development. One of the most useful land-use policy tools is to change zoning laws to promote mixed-use development.18 Zoning laws that forbid commercial development in residential areas promote sprawl because they require residents to travel greater distances to buy groceries, shop for clothes, and so on. Zoning laws can also be written to encourage high-density development and to require sidewalks and bike lanes.
Another important policy tool for promoting smart growth is to take steps to prevent development outside of a defined urban area, such as forbidding new housing construction on rural land, or setting administrative boundaries for city services, such as water and sewer connections.18 The government can also use economic incentives to promote smart growth. Developers that follow smart-growth principles can be deemed eligible for reduced fees that help offset the costs of smart-growth development, such as environmental impact fees. Conversely, developers that do not follow smart-growth principles can be subjected to higher fees.18 Finally, governments can also invest public funds in projects and land uses that facilitate smart growth, such as mass-transit systems, recreation areas, and schools conveniently situated in neighborhoods.2
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OBJECTIONS TO SMART GROWTH
Although smart growth appears to be a promising alternative to urban sprawl that could benefit public health and the environment, it has met with stiff resistance in some communities.11,13,15,18,26 The following are five of the most frequently voiced objections to smart-growth philosophies and policies:
Smart growth can decrease property values.11–13 Property values may be adversely affected when high-density housing units are built in an area where low-density housing prevails because the increase in population density may exacerbate local traffic, congestion, and crime, which reduces property values. Property values may also be negatively affected by commercial development in a residential area, because commercial development can increase traffic and crime. Crime may also increase when mass transit connects a residential area to a location where crime is more prevalent, such as the inner city.
Smart growth can decrease the availability of affordable housing.14,15 Requiring developers to build planned communities with mixed uses, sidewalks, recreation areas, and bike paths may increase the cost of housing. Also, setting aside large undevelo