Urban sprawl
Urban sprawl is defined as "the rapid expansion of the geographic extent of cities and towns, often characterized by low-density residential housing, single-use zoning, and increased reliance on the private automobile for transportation". Urban sprawl has been described as the unrestricted growth in many urban areas of housing, commercial development, and roads over large expanses of land, with little concern for very dense urban planning.
Urban sprawl refers to a special form of urbanization, and it relates to the social and environmental consequences associated with such development. In modern times some suburban areas described as "sprawl" have less detached housing and higher density than the nearby core city. Medieval suburbs suffered from the loss of protection of city walls, before the advent of industrial warfare. Sometimes the urban areas described as the most "sprawling" are the most densely populated.
The modern disadvantages and costs of urban sprawl include increased travel time, transport costs, pollution, and destruction of the countryside. The revenue for building and maintaining urban infrastructure in these areas are gained mostly through property and sales taxes. Most jobs in the US are now located in suburbs generating much of the revenue, although a lack of growth will require higher tax rates.
In Europe, the term peri-urbanisation is often used to denote similar dynamics and phenomena, but the term urban sprawl is currently being used by the European Environment Agency. There is widespread disagreement about what constitutes sprawl and how to quantify it. For example, some commentators measure sprawl by residential density, using the average residential units per acre in a given area. Others associate it with decentralization, discontinuity, segregation of uses, and so forth.
The term urban sprawl is highly politicized and almost always has negative connotations. It is criticized for causing environmental degradation, intensifying segregation, and undermining the vitality of existing urban areas, and is attacked on aesthetic grounds. Few people openly support urban sprawl as such, due to the pejorative connotations of the term. The term has become a rallying cry for managing urban growth.
Definition
The term urban sprawl was often used in the letters between Lewis Mumford and Frederic J. Osborn, firstly by Osborn in his 1941 letter to Mumford and later by Mumford, generally condemning the waste of agricultural land and landscape due to suburban expansions. The term was used in an article in The Times in 1955 as a negative comment on the state of London's outskirts. Definitions of sprawl vary; researchers in the field acknowledge that the term lacks precision. Batty et al. defined sprawl as "uncoordinated growth: the expansion of community without concern for its consequences, in short, unplanned, incremental urban growth which is often regarded unsustainable". Bhatta et al. wrote in 2010 that despite a dispute over the precise definition of sprawl, there is a "general consensus that urban sprawl is characterized by unplanned and uneven pattern of growth, driven by a multitude of processes and leading to inefficient resource utilization".Reid Ewing has shown that sprawl has typically been characterized as urban developments exhibiting at least one of the following characteristics: low-density or single-use development, strip development, scattered development, and/or leapfrog development. He argued that a better way to identify sprawl was to use indicators rather than characteristics because this was a more flexible and less arbitrary method. He proposed using "accessibility" and "lack of functional open space" as indicators. Ewing's approach has been criticized for assuming that sprawl is defined by negative characteristics.
What constitutes sprawl may be considered a matter of degree and will always be somewhat subjective under many definitions of the term. Ewing has also argued that suburban development does not, per se, constitute sprawl depending on the form it takes, although Gordon & Richardson have argued that the term is sometimes used synonymously with suburbanization in a pejorative way.
Examples and counterexamples
According to the National Resources Inventory, about of land in the United States was developed between 1982 and 2017. Presently, the NRI classifies approximately 100,000 more square kilometres as developed than the Census Bureau classifies as urban. The difference in the NRI classification is that it includes rural development, which by definition cannot be considered to be "urban" sprawl. Currently, according to the 2000 Census, approximately 2.6 percent of the U.S. land area is urban. Approximately 0.8 percent of the nation's land is in the 37 urbanized areas with more than 1,000,000 population. In 2002, these 37 urbanized areas supported around 40% of the total American population.Nonetheless, some urban areas like Detroit have expanded geographically even while losing population. But it was not just urbanized areas in the U.S. that lost population and sprawled substantially. According to data in "Cities and Automobile Dependence" by Kenworthy and Laube, urbanized area population losses occurred while there was an expansion of sprawl between 1970 and 1990 in Amsterdam, Netherlands; Brussels, Belgium; Copenhagen, Denmark; Frankfurt, Hamburg and Munich, Germany; and Zürich, Switzerland, albeit without the dismantling of infrastructure that occurred in the United States.
Despite its sprawl, Metropolitan Los Angeles is the densest major urban area in the US, being denser than the New York urban area and the San Francisco urban area. Most of metropolitan Los Angeles is built at more uniform low to moderate density, leading to a much higher overall density for the entire region. This is in contrast to New York, San Francisco or Chicago which have compact, high-density cores surrounded by areas of very low-density suburban periphery, such as eastern Suffolk County in the New York metro area and Marin County in the San Francisco Bay Area.
Some cases of sprawl challenge the definition of the term and what conditions are necessary for urban growth to be considered sprawl. Metropolitan regions such as Greater Mexico City, Delhi National Capital Region Beijing, and the Greater Tokyo Area are often regarded as sprawling despite being relatively dense and mixed use.
History
Many theories speculate as to the reason for the creation of urban sprawl. The theory of "flight from blight" explains that aspects of living in urban areas, such as high taxes, crime rates, poor infrastructure and school qualities lead to many people moving out of urban areas and into surrounding suburban areas. According to The Limits to Growth, reasons why wealthier people move to suburbs include noise, pollution, crime, drug addiction, poverty, labor strikes, and breakdown of social services.Others suggest that urban sprawl is a natural product of population increases, higher wages, and therefore better access to housing. Improvement in transportation also means that individuals are able to live further from large cities and industrial hubs, thus increasing demand for better housing further from the noise of cities. This leads to the creation of sprawling residential land development surrounding densely packed urban areas.
Characteristics
Despite the lack of a clear agreed upon description of what defines sprawl most definitions often associate the following characteristics with sprawl.File:BosWash-Night-Labeled.png|upright=1.0|thumb|This picture shows the metropolitan areas of the Northeast Megalopolis of the United States demonstrating urban sprawl, including far-flung suburbs and exurbs illuminated at night.
Single-use development
This refers to a situation where commercial, residential, institutional and industrial areas are separated from one another. Consequently, large tracts of land are devoted to a single use and are segregated from one another by open space, infrastructure, or other barriers. As a result, the places where people live, work, shop, and recreate are far from one another, usually to the extent that walking, transit use and bicycling are impractical, so all these activities generally require a car. The degree to which different land uses are mixed together is often used as an indicator of sprawl in studies of the subject.According to this criterion, China's urbanization can be classified as "high-density sprawl", a seemingly self-contradictory term coined by New Urbanist Peter Calthorpe. He explains that despite the high-rise buildings, China's superblocks are largely single-use and surrounded by giant arterial roads, which detach different functions of a city and create an environment unfriendly to pedestrians.
Job sprawl and spatial mismatch
Job sprawl is another land use symptom of urban sprawl and car-dependent communities. It is defined as low-density, geographically spread-out patterns of employment, where the majority of jobs in a given metropolitan area are located outside of the main city's central business district, and increasingly in the suburban periphery. It is often the result of urban disinvestment, the geographic freedom of employment location allowed by predominantly car-dependent commuting patterns of many American suburbs, and many companies' desire to locate in low-density areas that are often more affordable and offer potential for expansion. Spatial mismatch is related to job sprawl and economic environmental justice. Spatial mismatch is defined as the situation where poor urban, predominantly minority citizens are left without easy access to entry-level jobs, as a result of increasing job sprawl and limited transportation options to facilitate a reverse commute to the suburbs.Job sprawl has been measured and documented in various ways. It has been shown to be a growing trend in America's metropolitan areas. The Brookings Institution has published multiple articles on the topic. In 2005, author Michael Stoll defined job sprawl simply as jobs located more than radius from the CBD, and measured the concept based on year 2000 U.S. census data. Other ways of measuring the concept with more detailed rings around the CBD include a 2001 article by Edward Glaeser and Elizabeth Kneebone's 2009 article, which show that sprawling urban peripheries are gaining employment while areas closer to the CBD are losing jobs. These two authors used three geographic rings limited to a radius around the CBD: or less, 3 to, and 10 to. Kneebone's study showed the following nationwide breakdown for the largest metropolitan areas in 2006: 21.3% of jobs located in the inner ring, 33.6% of jobs in the 3–10 mile ring, and 45.1% in the 10–35 mile ring. This compares to the year 1998 – 23.3%, 34.2%, and 42.5% in those respective rings. The study shows CBD employment share shrinking, and job growth focused in the suburban and exurban outer metropolitan rings.