A primary urban area (PUA) is an area defined by the Department for Communities and Local Government in the United Kingdom as a statistical tool for analysing the major cities of England, originating as part of their State of the English Cities report and database.
[1] The concept of a primary urban area was created in an attempt to enable economic and social comparisons between cities using definitions less arbitrary than the administrative boundaries of local authorities, but avoiding one problem of using the urban areas defined by the Office for National Statistics - that sprawling conurbations such as the West Yorkshire Urban Area, containing multiple distinct settlements with large degrees of physical and social independence, but that happen to touch, end up being treated as if they were a single city.
As primary urban areas were created to allow statistical comparisons, and the majority of statistics are produced based on administrative or electoral geographies, primary urban areas are approximated to local authority and ward level, or to an additional measure called a tract – similar in size to a ward but designed to be subject to fewer revisions over time.
[5] Primary urban areas are designed purely as a tool of statistical analysis and aren't intended to form definitive measures of cities for policy purposes.
[6] The PUA model and its Eurostat equivalent differ in their treatment of Wolverhampton: the former aggregates it with Birmingham, whereas the latter gives it its own larger urban zone.