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. They are oftentimes where most of a metropolitan areas jobs are located with some being predominantly residential. They can either be denser or less densely populated ...

, at the edge of a

metropolitan area A metropolitan area or metro is a region consisting of a densely populated urban area, urban agglomeration and its surrounding territories which share Industry (economics), industries, commercial areas, Transport infrastructure, transport network ...

, which has some economic and commuting connection to the metro area, low housing-density, and relatively high population-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 are typically desc ...

landscapes, holding a limited urban nature for its functional, economic, and social interaction with the

urban center Urban Center may refer to: * Urban center, human settlement with a high population density and infrastructure of built environment * Urban Center Plaza, plaza on the Portland State University campus in Portland, Oregon, United States * Urban Cen ...

, due to its dominant residential character. Exurbs 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 In linguistics, a blend—also known as a blend word, lexical blend, or portmanteau—is a word formed by combining the meanings, and parts of the sounds, of two or more words together.

of ''extra (outside)'' and ''urban'') was coined by Auguste Comte Spectorsky, in his 1955 book ''The Exurbanites'', to describe the ring of prosperous communities beyond the

suburb A suburb (more broadly suburban area) is an area within a metropolitan area. They are oftentimes where most of a metropolitan areas jobs are located with some being predominantly residential. They can either be denser or less densely populated ...

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 o ...

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 their distance from the

. Exurbs can be defined in terms of

population density Population density (in agriculture: Standing stock (disambiguation), standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans, but sometimes to other living organisms too. It is a key geog ...

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 Tong'an District () is a northern mainland district of Xiamen which faces Quemoy County, Republic of China. To the north is Anxi and Nan'an, and to the south is Jimei. Tong'an is also east of Lianxiang and Changqin to the West. It covers

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. Changping has a population of 2,269,487 as of November 2020, making it the most populous suburban district of Beijing. Hist ...

, Beijing * Shunyi District, 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 Brookings, is an American think tank that conducts research and education in the social sciences, primarily in economics (and tax policy), metropolitan policy, governance, foreign policy, global econo ...

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 federally funded research and development centers, federally funded research and development center in Oak Ridge, Tennessee, United States. Founded in 1943, the laboratory is sponsored by the United Sta ...

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, BosWash, or BosNYWash, is the most populous megalopolis exclusively within the United States, with slightly over 50 million resident ...

, 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