Urban sprawl is the unchecked spreading of a city or its suburbs over rural land at the edge of an urban area. It often involves the development of rural areas and open space into residential or shopping areas over time. There are many concerns over urban sprawl and its consequences, as much for the residents as for the local environment. Most residents of typical urban sprawl neighborhoods live in single-family homes and commute by automobile to work.

The term urban sprawl generally has negative connotations due to the environmental problems it poses. Because people in sprawling neighborhoods tend to drive more than those who don’t, urban sprawl is sometimes seen as contributing to area air pollution. It has also been linked to obesity, given the fact that walking or bicycling are not viable commuting options for someone commuting from the edge to the center of an urban area.

Traditional cities, like many small and mid-sized cities in modern-day Europe, were compact and efficient. However, the preferences of many consumers, especially in the United States, have led to the development of cities and suburbs that are built outward instead of upward. Developments such as shopping malls, fast food chains, strip malls, and housing subdivisions are especially typical of urban sprawl. Subdivisions are the largest contributors to the overall inefficient use of space that characterizes sprawl. They often have only a few places to enter and exit, causing main roads to have more traffic at these points.

Other than the specific items just described, there are certain general patterns that are typical of urban sprawl, which tend to occur more or less all at once in this type of growth. Low-density land use is the first, where the amount of land consumed per capita is much higher than in more densely populated city areas. Wide streets, large lawns, and landscaping are typical in this pattern.

Single-use zoning is also a common part of urban sprawl. This is a situation where residential, commercial, and industrial areas are kept separate from one another, usually by a distance that makes walking impractical for getting around. This leads to dependence on automobiles for transportation. Areas of urban sprawl are highly dependent on cars because of the isolation of residential areas from those where residents work or shop. Urban sprawl, while common in developed countries, is not limited to them. Many cities in developing countries, such as Mexico City, are suffering from it, and its effects can be magnified in areas of economic poverty.