Will smart growth result in more traffic congestion and air pollution? Wendell Cox presents the argument for sprawl and against urban 'smart growth' development.
Over the past 50 years, America's suburbs have grown to contain most urban residents. As the nation has become more affluent, people have chosen to live in single family dwellings on individual lots and have also obtained automobiles to provide unprecedented mobility.
As population has continued to grow, the amount of new roadway constructed has fallen far short of the rise in automobile use. As a result, American urban areas are experiencing increased traffic congestion. The good news is that improved vehicle technology has made the air cleaner in many cities than it has been in decades.
Low density suburbanization is perceived by the anti-sprawl movement as inefficiently using land, by consuming open space and valuable agricultural land. The anti-sprawl movement believes that suburbanization has resulted in an inappropriate amount of automobile use and highway construction and favors public transit and walking as alternatives. Moreover, they blame suburbanization for the decline of the nation's central cities.
The anti-sprawl movement has embraced "smart growth" policies. In general, smart growth would increase urban population densities, especially in corridors served by rail transit. Development would be corralled within urban growth boundaries. There would be little or no highway construction, replaced instead by construction of urban rail systems. Attempts would be made to steer development toward patterns that would reduce home to work travel distances, making transit and walking more feasible. The anti-sprawl movement suggests that these policies will improve the quality of life, while reducing traffic congestion and air pollution.
But the anti-sprawl diagnosis is flawed.
- Urbanization does not threaten agricultural land. Since 1950, urban areas of more than 1,000,000 have consumed an amount of new land equal to barely 1/10th the area taken out of agricultural production. The cultpit is improved agricultural productivity, not development.
- Only 15 percent of suburban growth has come from declining cental cities. Most growth is simple population gain and the movement of people from rural to suburban areas. The same process is occurring throughout affluent nations, from Europe to Asia and Australia. In these nations, virtually all urban growth in recent decades has been suburban, while central cities have lost population. Since 1950 Copenhagen has lost 40% of its population and Paris 25%.
- There is no practical way for low density urban areas to be redesigned to significantly increase transit and walking. Whether in America or Europe, most urban destinations are reasonably accessible only by automobile. Transit can be an effective alternative to the automobile only to dense core areas, such as the nation's largest downtowns.
- Large expanses of land are already protected as open space. All of the nation's urban development, in small towns and major metropolitan areas, accounts for approximately four percent of land (excluding Alaska).
Ironically, smart growth will bring more traffic congestion and air pollution, because it will concentrate automobile traffic in a smaller geographical space. International and US data shows that:
- higher population densities are associated with greater traffic congestion.
- the slower, more stop-and-go traffic caused by higher densities increase air pollution.
Further, urban growth boundaries ration land for development. Rationing, whether of gasoline or of land drives up prices. For example, in smart growth oriented Portland, Oregon, housing affordability has declined considerably more than in any other major metropolitan area. This makes it unnecessarily difficult for low income and many minority citizens to purchase their own homes.
The anti-sprawl movement has not identified any threat that warrants its draconian poliicies. As the "Lone Mountain Compact" puts it, people should be allowed to live and work where and how they like absent a material threat to others.
As urban areas continue to expand -- which they must do in a growing affluent nation -- sufficient street and highway capacity should be provided, so that traffic congestion and air pollution are minimized.
Wendell Cox is principal of Wendell Cox Consultancy, an international public policy firm. He has provided consulting assistance to the United States Department of Transportation and was certified by the Urban Mass Transportation Administration as an "expert" for the duration of its Public-Private Transportation Network program (1986-1993). He has consulted for public transit authorities in the United States, Canada, Australia and New Zealand and for public policy organizations.

New Florida Law Curbs HOA Power
The legislation seeks to cut down on ‘absurd’ citations for low-level violations.

New Tennessee Law Allows No-Cost Incentives for Affordable Housing
Local governments in the Volunteer State can now offer developers incentives like increased density, lower parking requirements, and priority permitting for affordable housing projects.

Planners’ Complicity in Excessive Traffic Deaths
Professor Wes Marshall’s provocatively-titled new book, "Killed by a Traffic Engineer," has stimulated fierce debates. Are his criticisms justified? Let’s examine the degree that traffic engineers contribute to avoidable traffic deaths.

Study: Housing Crisis is About Affordability, not Supply
New research shows that there is no overall shortage of housing units, but all U.S. metropolitan areas face a severe lack of affordable units for low-income renters.

Are Race-Based Lawsuits Affecting Community Lenders?
Shelterforce spoke with community lending leaders and experts about the current mood across the sector. What, if anything, are organizations doing to avoid becoming the next target of conservative activists?

New Park Promotes Community and Connectivity in Lewisville, Texas
The city of Lewisville just celebrated the opening of Glory Park/Parque la Gloria, helping to improve park access and the quality of life for residents.
City of Madera
City of Santa Clarita
Borough of Carlisle
HUD's Office of Policy Development and Research
Chaddick Institute at DePaul University
HUD's Office of Policy Development and Research
Colorado Energy Office
Pima County Community College District
City of Piedmont, CA

Write for Planetizen
Urban Design for Planners 1: Software Tools
This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.
Planning for Universal Design
Learn the tools for implementing Universal Design in planning regulations.