Sprawl, also called urban sprawl, is the replacement of agricultural land or unoccupied land by large areas of mainly single-family housing, accompanied by commercial and other structures, typically surrounding or near older cities or towns. It usually occurs relatively quickly, but can take different forms, depending on whether it occurs in a developed country with a high degree of automobile usage or a developing country with low automobile usage.
In the developed countries sprawl is typically characterized by large numbers of single-family homes, often with lawns, and usually having lot sizes substantially larger than those of the nearby older neighborhoods and thus a much lower population density. The building of individual houses, groups of houses and other facilities (educational, governmental, industrial, etc.) often occurs in a leapfrog manner, with large areas of land between them remaining vacant, often for many years.
This sprawl also features wider streets along with extensive parking lots for commercial, industrial and other facilities, often far larger in area than the facilities themselves. Alternative transportation is usually minimal, and even when it exists, usage is low.
Planning by local or regional governments is usually involved to some extent in the growth of sprawl in the developed countries. It usually includes such things a building codes and minimum lot sizes. It has traditionally focussed on facilitating automobile use by specifying minimum street widths and minimum parking requirements and has typically largely ignored walkability and the provision of alternative transportation.
In the developing countries sprawl mostly occurs with little or no government involvement. It is characterized by large numbers of small, single-family or multi-generational homes often packed tightly together with little or no space between them, and it can have a far higher population density than sprawl in developed countries.