A conurbation is a region comprising a number of metropolises, cities, large towns, and other urban areas which through population growth and physical expansion, have merged to form one continuous urban or industrially developed area. In most cases, a conurbation is a polycentric urbanised area in which transportation has developed to link areas. They create a single urban labour market or travel to work area.
Patrick Geddes coined the term in his book Cities In Evolution (1915). He drew attention to the ability of the new technology at the time of electric power and motorised transport to allow cities to spread and agglomerate together, and gave as examples "Midlandton" in England, the Ruhr in Germany, Randstad in the Netherlands, and the Northeastern Seaboard in the United States.
The term as described is used in Britain whereas in the United States, each polycentric "metropolitan area" may have its own common designation such as San Francisco Bay Area or the Dallas–Fort Worth metroplex. Internationally the term "urban agglomeration" is often used to convey a similar meaning to "conurbation". A conurbation should be contrasted with a megalopolis. In a megalopolis the urban areas are close but not physically contiguous, and the merging of labour markets has not yet developed. A conurbation should also be contrasted with a megacity. A megacity is hierarchical with an indisputable dominant urban core, whereas a conurbation is polycentric and no single urban centre has the dominant role over all other centres.
Africa
Mauritius
The cities and towns of Port Louis, Beau Bassin-Rose Hill, Curepipe, Quatre Bornes, Vacoas-Phoenix and other urbanized villages form a large and central conurbation on the island of Mauritius. A large part of this conurbation is located in the district of Plaines Wilhems. The network of urban areas has a total population of 606,650 (49% of the island's population) as of 2011.
Morocco
Rabat-Salé-Kénitra
Nigeria
Lagos is a conurbation formed through the merged development of the initial Lagos city area with other cities and towns including Ikeja and Ojo. Also various suburban communities such as Agege, Alimosho, Ifako-Ijaiye, Kosofe, Mushin, Oshodi and Shomolu are included in the area.
South Africa
Johannesburg, Ekurhuleni (East Rand), and Tshwane (greater Pretoria) merged to form a region that has a population of 14.6 million.
Oceania
Australia
Albury-Wodonga
Albury and Wodonga are cross border cities which are geographically separated by the Murray River. Albury on the north of the river is part of New South Wales, while Wodonga on the south bank is in Victoria. In the early 1970s Albury-Wodonga was selected as the primary focus of the Whitlam government's scheme to arrest the uncontrolled growth of Australia's large metropolitan areas (in particular Sydney and Melbourne) by encouraging decentralisation. The two cities combine to form an urban area with an estimated population of 93,603.
Canberra-Queanbeyan
A cross border built-up area comprising the nation's capital Canberra in the Australian Capital Territory and the city of Queanbeyan in New South Wales, which is considered by the Australian Bureau of Statistics to have a single labour market.
Newcastle, Sydney, Wollongong
This conurbation in New South Wales extends from Newcastle and surrounding satellite towns of the Hunter Valley through the Central Coast. It is broken up only by waterways and national parks, through to the greater Sydney metropolitan area and the Wollongong urban area. The total length from the top to the bottom of the conurbation is around 270km with a population of just over 6 million people.
Transport is linked throughout the region by motorways, the M1, M2, M4, M5, M7, M8, M15 and M31. An extensive public transport network allows for commuting for work or services across and between multiple distinct but joined centres, with NSW TrainLink's intercity network serving Sydney, the Central Coast, Newcastle, the Hunter Valley and the Illawarra.