An exurb (or alternately: exurban area) is an area outside the typically denser inner

suburban area A suburb (more broadly suburban area) is an area within a metropolitan area, which may include commercial and mixed-use, that is primarily a residential area. A suburb can exist either as part of a larger city/urban area or as a separa ...

, at the edge of a

metropolitan area A metropolitan area or metro is a region that consists of a densely populated urban agglomeration and its surrounding territories sharing industries, commercial areas, transport network, infrastructures and housing. A metro area usually ...

, which has some economic and commuting connection to the metro area, low housing density, and growth. It shapes an interface between urban and

rural In general, a rural area or a countryside is a geographic area that is located outside towns and cities. Typical rural areas have a low population density and small settlements. Agricultural areas and areas with forestry typically are de ...

landscapes holding a limited urban nature for its functional, economic, and social interaction with the urban center, due to its dominant residential character. They consist of "agglomerations of housing and jobs outside the municipal boundaries of a primary city" and beyond the surrounding suburbs.

Definitions

The word ''exurb'' (a

portmanteau A portmanteau word, or portmanteau (, ) is a blend of wordssuburb A suburb (more broadly suburban area) is an area within a metropolitan area, which may include commercial and mixed-use, that is primarily a residential area. A suburb can exist either as part of a larger city/urban area or as a separ ...

s, that are

commuter town A commuter town is a populated area that is primarily residential rather than commercial or industrial. Routine travel from home to work and back is called commuting, which is where the term comes from. A commuter town may be called by many ...

s for an urban area. In other uses the term has expanded to include popular extraurban districts which nonetheless may have poor transportation and underdeveloped economies due to distance from the urban center. Exurbs can be defined in terms of population density across the extended urban area, for example "the urban core (old urban areas including Siming and Huli, where the population density is greater than 51 persons per ha), the suburban zone (old urban and new urban transitional zones including Haicang and Jimei, where the population density is greater than 8 persons per ha), and the exurban areas (newly urbanized areas including Tong'an and Xiang'an, where the population density is less than 8 persons per ha)". The mixture of urban and rural environments raises ecological issues.

Examples by country

China

Changping District Changping District (), formerly Changping County (), is a district situated in the suburbs of north and northwest Beijing. History Changping County and Jundu County which administered the area were established in the Han Dynasty. Changping was i ...

, Beijing *

Shunyi District Shunyi District () is an administrative district of Beijing, located to the northeast of the city's urban core. As of 2014, the population of the district is around 983,000, of which approximately 601,000 have local residency permits. The Beiji ...

, Beijing *Shenjia village, Loudi city, Hunan province

Russia

* Rublyovka, Moscow

United States

Since the ''Finding Exurbia'' report by the

Brookings Institution The Brookings Institution, often stylized as simply Brookings, is an American research group founded in 1916. Located on Think Tank Row in Washington, D.C., the organization conducts research and education in the social sciences, primarily in e ...

in 2006, the term is generally used for areas beyond suburbs and specifically less densely built and populated than the suburbs to which the exurbs' residents commute. To qualify as exurban, a

census tract A census tract, census area, census district or meshblock is a geographic region defined for the purpose of taking a census. Sometimes these coincide with the limits of cities, towns or other administrative areas and several tracts commonly exis ...

must meet three criteria: # Economic connection to a large metropolis. # Low housing density: bottom third of census tracts with regard to housing density. In 2000, this was a minimum of per resident. # Population growth exceeding the average for its central

. These are based on published datasets. Alternative approaches include working with

Oak Ridge National Laboratory Oak Ridge National Laboratory (ORNL) is a U.S. multiprogram science and technology national laboratory sponsored by the U.S. Department of Energy (DOE) and administered, managed, and operated by UT–Battelle as a federally funded research an ...

LandScan data and GIS. Exurban areas incorporate a mix of rural development (e.g., farms and open space) and in places, suburban-style development (e.g., tracts of single-family homes, though usually on large lots). In long-settled areas, such as the U.S.

Northeast megalopolis The Northeast megalopolis, also known as the Northeast Corridor, Acela Corridor, Boston–Washington corridor, or BosWash, is the world's largest megalopolis in terms of economic output and the second most populous megalopolis in the United Sta ...

, exurban areas incorporate pre-existing towns, villages and smaller cities, as well as strips of older single-family homes built along pre-existing roads that connected the older population centers of what was once a rural area. The Brookings Institution listed exurban counties, defined as having at least 20% of their residents in exurban

Census tract A census tract, census area, census district or meshblock is a geographic region defined for the purpose of taking a census. Sometimes these coincide with the limits of cities, towns or other administrative areas and several tracts commonly exis ...

References