Urban sprawl

It is criticized for causing environmental degradation, intensifying segregation, and undermining the vitality of existing urban areas, and is attacked on aesthetic grounds.

[32] 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.

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.

[20] 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 (huge residential blocks) are largely single-use and surrounded by giant arterial roads, which detach different functions of a city and create an environment unfriendly to pedestrians.

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 (CBD), and increasingly in the suburban periphery.

The study shows CBD employment share shrinking, and job growth focused in the suburban and exurban outer metropolitan rings.

New Urbanist architectural firm Duany Plater-Zyberk & Company state that housing subdivisions "are sometimes called villages, towns, and neighbourhoods by their developers, which is misleading since those terms denote places that are not exclusively residential".

Some strip malls are undergoing a transformation into Lifestyle centers; entailing investments in common areas and facilities (plazas, cafes) and shifting tenancy from daily goods to recreational shopping.

Unlike the strip mall, this is usually composed of a single building surrounded by a parking lot that contains multiple shops, usually "anchored" by one or more department stores.

Shopping malls also tend to serve a wider (regional) public and require higher-order infrastructure such as highway access and can have floorspaces in excess of 1 million sq ft (93,000 m2).

[56] Fast food chains are often built early in areas with low property values where the population is expected to boom and where large traffic is predicted, and set a precedent for future development.

Duany Plater Zyberk & Company believe that this reinforces a destructive pattern of growth in an endless quest to move away from the sprawl that only results in creating more of it.

A review by Brian Czech and colleagues[57] finds that urbanization endangers more species and is more geographically ubiquitous in the mainland United States than any other human activity.

[58] Although the effects can be mitigated through careful maintenance of native vegetation, the process of ecological succession and public education, sprawl represents one of the primary threats to biodiversity.

[58] Regions with high birth rates and immigration are therefore faced with environmental problems due to unplanned urban growth and emerging megacities such as Kolkata.

[59] Other problems include: At the same time, the urban cores of these and nearly all other major cities in the United States, Western Europe, and Japan that did not annex new territory experienced the related phenomena of falling household size and, particularly in the U.S., "white flight", sustaining population losses.

Due to the larger area consumed by sprawling suburbs compared to urban neighborhoods, more farmland and wildlife habitats are displaced per resident.

On average, suburban residents generate more per capita pollution and carbon emissions than their urban counterparts because of their increased driving,[35][68][69] as well as larger homes.

Duany and Plater-Zyberk believe that in traditional neighborhoods the nearness of the workplace to retail and restaurant space that provides cafes and convenience stores with daytime customers is an essential component to the successful balance of urban life.

Furthermore, they state that the closeness of the workplace to homes also gives people the option of walking or riding a bicycle to work or school and that without this kind of interaction between the different components of life the urban pattern quickly falls apart.

[50] James Howard Kunstler has argued that poor aesthetics in suburban environments make them "places not worth caring about", and that they lack a sense of history and identity.

She mentions that the lack of a common definition, the need for more quantitative measures "a broader view both in time and space, and greater comparison with alternative urban forms" would be necessary to draw firmer conclusions and conduct more fruitful debates.

[92][93] NumbersUSA, a national organization advocating immigration reduction, also opposes urban sprawl,[94] and its founder, Roy Beck, specializes in the study of this issue.

[96] Gordon and his frequent collaborator, Harry Richardson have argued that The principle of consumer sovereignty has played a powerful role in the increase in America’s wealth and in the welfare of its citizens.

[22] Others, for example Kenneth T. Jackson[98] have argued that since low-density housing is often (notably in the U.S.) subsidized in a variety of ways, consumers' professed preferences for this type of living may be over-stated.

[114] In Australia, it is claimed by some that housing affordability has hit "crisis levels" due to "urban consolidation" policies implemented by state governments.

Gordon & Richardson for example argue that the costs of building new public transit is disproportionate to the actual environmental or economic benefits, that land use restrictions will increase the cost of housing and restrict economic opportunity, that infill possibilities are too limited to make a major difference to the structure of American cities, and that the government would need to coerce most people to live in a way that they do not want to in order to substantially change the impact of sprawl.

The terms "compact city" and "urban intensification" are often used to describe similar concepts in Europe, and particularly in the UK, where it has influenced government policy and planning practice in recent years.

[125] Factors influencing walkability include the presence or absence and quality of footpaths, sidewalks, or other pedestrian right-of-ways, traffic and road conditions, land use patterns, building accessibility, and safety, among others.