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Census Urbanized Areas and MPO/TMA Designation

FAQ Topic 1: Definitions

Urban Area - A Census-designated area consisting of a central core and adjacent densely settled territory that together contain at least 2,500 residents.

Note: Until 2000, urban areas were limited to areas with populations of 50,000 residents or more. However, since Census 2000, urban areas have included both Urbanized Areas (UZA) with populations of 50,000 residents or more, and Urban Clusters (UC) with populations of 2,500 to 49,999 residents. The Census Bureau uses the term "urban area" to refer to both UZAs and UCs collectively.

Urbanized Area (UZA) - A Census-designated urban area with 50,000 residents or more.

Image shows a geographic area with several counties and three municipalities. An urbanized area boundary is shown surrounding the largest municipality, overlapping two county boundaries.

Note: USDOT typically uses the acronym "UZA" to refer to Urbanized Areas. The Census Bureau uses the acronym "UA." They are synonymous.

Urban Cluster (UC) - A Census-designated urban area with at least 2,500 residents and no more than 49,999 residents.

Image shows a geographic area with several counties and three municipalities. An urbanized area boundary is shown surrounding the largest municipality, overlapping two county boundaries. An urban cluster boundary is shown surrounding the two smaller municipalities.

Adjusted UZA - A Census-defined UZA boundary that has been adjusted by a State DOT to include additional territory. Typically created to smooth irregular UZA boundaries, the Adjusted UZA must be submitted to FHWA for approval.

Image shows a geographic area with several counties and three municipalities. An urbanized area boundary is shown surrounding the largest municipality, overlapping two county boundaries. An urban cluster boundary is shown surrounding the two smaller municipalities. An adjusted UZA boundary is shown surrounding the urbanized area boundary. The adjusted UZA boundary has smoother edges than the urbanized area boundary.

Note: Federal transportation legislation allows for State and local officials to cooperatively expand the Census-defined UZA boundaries. The adjusted UZA must encompasses the entire Census-designated UZA and is subject to approval by the Secretary of Transportation (23 USC 101(a)(36) -(37) and 49 USC 5302(a)(16) - (17)).

Population derived from the Adjusted UZA is not used in the federal transportation programs where a population count is required for funding allocations. Where a population count is called for it is the Census-designated UZA population that is used.

The Adjusted UZA:

  1. Must encompass the entire Urbanized Area or urban cluster area as designated by the Bureau of Census.
  2. Should be one, single contiguous area.
  3. Should encompass areas outside of municipality boundaries that have urban characteristics with residential, commercial, industrial, or national defense land uses that are consistent with or related to the development patterns with the boundary.
  4. Should encompass all large traffic generators that are within a reasonable distance from the urban area (e.g., fringe area public parks, large places of assembly, large industrial plants, etc.). This would include transportation terminals and their access roads (e.g., airports, seaports).

If an Adjusted UZA is not accomplished by June 2014 FHWA will consider the original 2010 Census UZA boundaries as the official boundaries in place for the 2014 HPMS data submission.

Urban Place - No longer exists in Census parlance.

Note: Prior to Census 2000, a place (incorporated city or town) with a population of 2,500 or more was classified as "urban" without regard to population density. The Census continues to define Incorporated Places and Census Designated Places, but these are not used as part of the urban/rural classification.

Metropolitan Planning Area (MPA) - The boundary in which the metropolitan transportation planning process must be carried out.

Image shows a geographic area with several counties and three municipalities. An urbanized area boundary is shown surrounding the largest municipality, overlapping two county boundaries. An urban cluster boundary is shown surrounding the two smaller municipalities. An adjusted UZA boundary is shown surrounding the urbanized area boundary. The adjusted UZA boundary has smoother edges than the urbanized area boundary. A metropolitan planning area boundary is shown encompassing the urbanized area boundary and surrounding areas. The metropolitan planning area boundary does not necessarily conform to county boundaries.

Note: The MPA must encompass the UZA(s) and the contiguous geographic area(s) likely to become urbanized within the next 20 years. In some cases, the MPA encompasses the entire metropolitan statistical area (MSA) or combined statistical area (CSA), as defined by the Office of Management and Budget (23 CFR 450.104).

Metropolitan Statistical Area (MSA) / Combined Statistical Area (CSA) - Geographies defined by the Office of Management and Budget (OMB) for use in tabulating statistical data about metropolitan areas.

Image shows a geographic area with several counties and three municipalities. An urbanized area boundary is shown surrounding the largest municipality, overlapping two county boundaries. An urban cluster boundary is shown surrounding the two smaller municipalities. A metropolitan statistical area boundary is shown encompassing all counties that contain a portion of the urbanized area. The metropolitan statistical area conforms exactly to county boundaries.

Note: MSAs consist of the core counties surrounding a UZA, plus adjacent counties with strong commuting patterns to and from the core counties. A CSA combines an MSA and one or more adjacent additional statistical areas defined by OMB.

Metropolitan Planning Organization (MPO) - The designated local decision-making body that is responsible for carrying out the metropolitan transportation planning process.

Note: Every UZA must be represented by an MPO (23 USC 134(b) and 49 USC 5303(c)).

Transportation Management Area (TMA) - A UZA with a population over 200,000, designated by the Secretary of Transportation.

Note: In some cases a UZA with less than 200,000 residents has been designated as a TMA, upon special request from the Governor and the MPO designated for the area.

Transportation Improvement Program (TIP) - A prioritized listing/program of transportation projects covering a period of four years that is developed by an MPO as part of the metropolitan transportation planning process, consistent with the metropolitan transportation plan (MTP), and required for projects to be eligible for funding under title 23 U.S.C. and title 49 U.S.C. Chapter 53.

Metropolitan Transportation Plan (MTP) - The long-range transportation plan for a metropolitan area. The MTP is the statement of the ways the region plans to invest in the transportation system over the next 20-25 years.

Congestion Management Process (CMP) - A way of systematically considering congestion-related issues using a set of technical tools, and basing evaluations on a discrete set of locally determined performance measures. A CMP is required for all TMAs.

For additional information

Updated: 10/17/2013
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