Urban ‘is a function of (1) sheer population size, (2) space (land area), (3) the ratio of population to space (density or concentration), and (4) economic and social organization.’

The OECD-EU classification identifies functional urban areas beyond city boundaries, to reflect the economic geography of where people live and work… Defining urban areas as functional economic units can better guide the way national and city governments plan infrastructure, transportation, housing and schools, space for culture and recreation. Improved planning will