Functional urban area

The functional urban area (FUA), previously known as larger urban zone (LUZ), is a measure of the population and expanse of metropolitan and surrounding areas which may or may not be exclusively urban. It consists of a city and its commuting zone, which is a contiguous area of spatial units that have at least 15% of their employed residents working in the city.

The FUA represents an attempt at a harmonised definition of the metropolitan area. Eurostat's objective was to have an area from which a significant share of the residents commute into the city, a concept known as the "functional urban region." To ensure a good data availability, Eurostat adjusts the FUA boundaries to administrative boundaries that approximate the functional urban area.

History
The definition was introduced under the name Larger urban zone (LUZ) in 2004 by Eurostat, the statistical agency of the European Union (EU), in agreement with the national statistics offices in the member states. Eurostat data is provided only for zones in the EU countries, candidate countries and EFTA countries. Several cities were excluded by definition from the 2004 list of LUZs on technical, definitional grounds, such as the coincidence of the metropolitan area with the urban zone.

In 2006 LUZ definitions were changed significantly, improving the comparability of LUZ definitions across different countries, and allowing for almost all cities to be included.

In 2011, the European Commission has developed a new definition of LUZ in cooperation with the OECD. The term Larger urban zone (LUZ) was later renamed as the Functional urban area (FUA).

In 2020, the Food and Agriculture Organization, the United Nations Human Settlements Programme, the International Labour Organization, and the World Bank have also adopted the Functional urban area as their definition for delimitation of metropolitan areas.

List of functional urban areas by population as of 2017
This is a list of functional urban areas by population as of 2017. The 2004 Urban Audit also includes cities from EFTA countries (Iceland, Liechtenstein, Norway and Switzerland) and EU candidate countries, although the only candidate country for which there is available data is Turkey. Some cities, including Marseille, Lille, Nice, Cordoba, Badajoz, Toulon and Montpellier were excluded from the 2004 list on technical, definitional grounds, such as the coincidence of the metropolitan area with the urban zone.

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List of functional urban areas
This is a list of functional urban areas. The Urban Audit also includes cities from EFTA countries (Iceland, Liechtenstein, Norway and Switzerland) and EU candidate countries. The Organisation for Economic Co-operation and Development (OECD) uses a similar definition of Functional Urban Area to represent population sizes of cities in OECD countries. This data is also included.

The figures in the Eurostat database are an attempt at a compromise between harmonised data for all of the European Union, and with availability of statistical data, making comparisons more accurate.

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