This notice provides the Census Bureau's final criteria for defining urban areas based on the results of the 2020 Decennial Census. This notice also provides a summary of comments received in response to the proposed criteria published in the Federal Register on February 19, 2021, as well as the Census Bureau's responses to those comments. The Census Bureau delineates urban areas after each decennial census by applying specified criteria to decennial census and other data. Since the 1950 Census, the Census Bureau has reviewed and revised these criteria, as necessary, for each decennial census in order to improve the classification of urban areas by taking advantage of newly available data and advancements in geographic information processing technology.
The Census Bureau's urban-rural classification is fundamentally a delineation of geographical areas, identifying individual urban areas as well as the rural portion of the nation. The Census Bureau's urban areas represent densely developed territory, and encompass residential, commercial, and other non-residential urban land uses. The boundaries of this urban footprint have been defined using measures based primarily on population counts and residential population density, and also on criteria that account for non-residential urban land uses, such as commercial, industrial, transportation, and open space that are part of the urban landscape. Since the 1950 Census, when the Census Bureau first defined densely settled urbanized areas of 50,000 or more people, the urban area delineation process has addressed non-residential urban land uses through criteria designed to account for commercial enclaves, special land uses such as airports, and densely developed noncontiguous territory.
In developing criteria for delineating urban areas, the Census Bureau uses an objective approach that is designed to meet the needs of a broad range of analysts and users interested in the definition of and data for urban and rural communities for statistical purposes. The Census Bureau recognizes that some federal and state agencies use the Census Bureau's urban-rural classification for allocating program funds, setting program standards, and implementing aspects of their programs. The agencies that use the classification and data for such nonstatistical uses should be aware that the changes to the urban area criteria also might affect the implementation of their programs.
While the Census Bureau is not responsible for the use of its urban-rural classification in nonstatistical programs, we will work with tribal, federal, state, or local agencies as well as stakeholders, as appropriate, to ensure understanding of our classification. Agencies using the classification for their programs must ensure that the classification is appropriate for their use.
Over the course of a century defining urban areas, the Census Bureau has introduced conceptual and methodological changes to ensure that the urban-rural classification keeps pace with changes in settlement patterns and with changes in theoretical and practical approaches to interpreting and understanding the definition of urban areas. Prior to the 1950 Census, the Census Bureau primarily defined “urban” as any population, housing, and territory located within incorporated places with a population of 2,500 or more. That definition was easy and straightforward to implement, requiring no need to calculate population density; to understand and account for actual settlement patterns on the ground in relation to boundaries of legal/administrative units; or to consider densely settled populations existing outside incorporated municipalities. For much of the first half of the twentieth century, that definition was adequate for defining “urban” and “rural” in the United States, but by 1950 it became clear that it was incomplete.
Increasing suburbanization, particularly outside the boundaries of large incorporated places led the Census Bureau to adopt the urbanized area concept for the 1950 Census. At that time, the Census Bureau formally recognized that densely settled communities outside the boundaries of incorporated municipalities were just as “urban” as the densely settled population inside those boundaries. Outside urbanized areas of 50,000 or more people, the Census Bureau continued to recognize urban places with at least 2,500 and less than 50,000 persons. This basic conceptual approach to identifying urban areas remained in effect through the 1990 Census, although with some changes to criteria and delineation methods.
The Census Bureau adopted six substantial changes to its urban area criteria for the 2000 Census:
Defining urban clusters using the same criteria as urbanized areas.
Disregarding incorporated place and census designated place (CDP) boundaries when defining urbanized areas and urban clusters.
Adopting 500 persons per square mile (PPSM) as the minimum density criterion for recognizing some types of urban territory.
Increasing the maximum jump distance for linking densely developed territory separated from the main body of the urban area by intervening low density territory from 1.5 to 2.5 miles. This recognized the prospect that larger clusters of non-residential urban uses might offset contiguity of densely settled territory.
Introducing the hop concept to provide an objective basis for recognizing that nonresidential urban uses, such as small commercial areas or parks, create small gaps between densely settled residential territory, but are part of the pattern of urbanization.
Adopting a zero-based approach to defining urban areas.
For the 2010 Census, the Census Bureau adopted moderate changes and enhancements to the criteria to improve upon the classification of urban and rural areas while continuing to meet the objective of a uniform application of criteria nationwide. These changes were:
Use of census tracts as analysis units in the initial phase of delineation.
Use of land use/land cover data from the National Land Cover Database (NLCD) to identify qualifying areas of non-residential urban land uses.
Qualification of airports for inclusion in urban areas.
Elimination of the designation of central places within urban areas.
Requirement for minimum population residing outside institutional group quarters.
Splitting large urban agglomerations.
The notice published in the Federal Register on February 19, 2021 (86 FR 10237) requested comments on proposed criteria for delineating the 2020 Census urban areas. The Census Bureau received 106 responses directly related to the proposed Urban Area Criteria. Responses were received from regional planning and nongovernmental organizations, municipal and county officials, Members of Congress, state governments, federal agencies, and individuals. The Census Bureau's decisions on changes that were incorporated into the Urban Area Criteria for the 2020 Census benefited greatly from the comments received in response, as well as comments received during webinars, conference presentations, consultations with professional geographers and other social scientists who work with and define urban and rural concepts and classifications, meetings with federal, state, and local officials and other users of data for urban areas, and additional research and investigation conducted by Census Bureau staff.
FR notice publishing Urban Area Criteria for 2020 Census: https://www.federalregister.gov/d/2022-06180