Health and environmental impact[edit]Urban sprawl is associated with a number of negative environmental and public health outcomes, with the primary result being increased dependence on automobiles.
Increased pollution and reliance on fossil fuel[edit]In the years following World War II, when vehicle ownership was becoming widespread, public health officials recommended the health benefits of suburbs due to soot and industrial fumes in the city center. However, air in modern suburbs is not necessarily cleaner than air in urban neighborhoods.[37] In fact, the most polluted air is on crowded highways, where people in suburbs tend to spend more time. On average, suburban residents generate more per capita pollution and carbon emissions than their urban counterparts because of their increased driving.[2][38]
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Increase in traffic and traffic-related fatalities[edit]A heavy reliance on automobiles increases traffic throughout the city as well as automobile crashes, pedestrian injuries, and air pollution.[40] Motor vehicle crashes are the leading cause of death for Americans between the ages of five and twenty-four and is the leading accident-related cause for all age groups.[41] Residents of more sprawling areas are at greater risk of dying in a car crash.[42]
Delays in emergency medical services response and fire department response times[edit]Research covered in the Journal of Economic Issues and State and Local Government Review shows a link between sprawl and emergency medical services response and fire department response delays.[43][44][45]
Increased obesity[edit]The American Journal of Public Health and the American Journal of Health Promotion, have both stated that there is a significant connection between sprawl, obesity, and hypertension.[46] Many urbanists argue that this is due to less walking in sprawl-type developments. Living in a car centered culture forces inhabitants to drive everywhere, thus walking far less than their urban (and generally healthier) counterparts.[47]
Decrease in social capital[edit]Urban sprawl may be partly responsible for the decline in social capital in the United States. Compact neighborhoods can foster casual social interactions among neighbors, while sprawl creates barriers. Sprawl tends to replace public spaces with private spaces such as fenced-in backyards.[4]
Decrease in land and water quantity and quality[edit]See also: Urban runoff
Due to the larger area consumed by sprawling suburbs compared to urban neighborhoods, more farmland and wildlife habitats are displaced per resident. As forest cover is cleared and covered with impervious surfaces (concrete and asphalt) in the suburbs, rainfall is less effectively absorbed into the ground water aquifers.[2] This threatens both the quality and quantity of water supplies. Sprawl increases water pollution as rain water picks up gasoline, motor oil, heavy metals, and other pollutants in runoff from parking lots and roads. Sprawl fragments the land, which increases the risk of invasive species spreading into the remaining forest.
Increased infrastructure costs[edit]Living in larger, more spread out spaces generally makes public services more expensive. Since car usage becomes endemic and public transport often becomes significantly more expensive, city planners are forced to build highway and parking infrastructure, which in turn decreases taxable land and revenue, and decreases the desirability of the area adjacent to such structures. Providing services such as water, sewers, and electricity is also more expensive per household in less dense areas.[48]
Increased personal transportation costs[edit]Residents of low-density areas spend a higher proportion of their income on transportation than residents of high density areas.[49] The RAC estimates that the average cost of operating a car in the UK is ?5,000 a year, most of which stems from financing costs and depreciation.[50] In comparison, a yearly underground ticket for a suburban commuter in London (where the average wage is higher than the national average[51]) costs ?1,000-1,500.
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Neighborhood quality[edit]Critics of sprawl maintain that sprawl erodes quality of life. 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. (Duany Plater-Zyberk 6, 28). 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.
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Groups that oppose sprawl[edit]The American Institute of Architects and the American Planning Association recommend against sprawl and instead endorses smart, mixed-use development, including buildings in close proximity to one another that cut down on automobile use, save energy, and promote walkable, healthy, well-designed neighborhoods.[57] The Sierra Club, the San Francisco Bay Area's Greenbelt Alliance, 1000 Friends of Oregon and counterpart organizations nationwide, and other environmental organizations oppose sprawl and support investment in existing communities.[58][59]