[Federal Register Volume 76, Number 164 (Wednesday, August 24, 2011)]
[Notices]
[Pages 53030-53043]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-21647]
[[Page 53029]]
Vol. 76
Wednesday,
No. 164
August 24, 2011
Part II
Department of Commerce
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Census Bureau
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Urban Area Criteria for the 2010 Census; Notice
Federal Register / Vol. 76, No. 164 / Wednesday, August 24, 2011 /
Notices
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DEPARTMENT OF COMMERCE
Bureau of the Census
[Docket Number 110714393-1393-01]
Urban Area Criteria for the 2010 Census
AGENCY: Bureau of the Census, Department of Commerce.
ACTION: Notice of final program criteria.
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SUMMARY: This notice announces the Bureau of the Census' (hereafter,
Census Bureau's) final criteria for defining urban areas based on the
results of the 2010 Decennial Census (the term ``urban area'' as used
throughout this notice refers generically to urbanized areas of 50,000
or more population and urban clusters of at least 2,500 and less than
50,000 population). This notice also provides a summary of comments
received in response to proposed criteria published in the August 24,
2010, Federal Register (75 FR 52174), as well as the Census Bureau's
response to those comments.
The Census Bureau's urban-rural classification is fundamentally a
delineation of geographic areas, identifying both individual urban
areas and the rural areas of the nation. The Census Bureau's urban
areas represent densely developed territory, and encompass residential,
commercial, and other nonresidential urban land uses. 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. The revisions over the years
reflect the Census Bureau's desire to improve the classification of
urban and rural territory to take advantage of newly available data, as
well as advancements in geographic information processing technology.
DATES: Effective Date: The Census Bureau will begin implementing the
criteria as of August 24, 2011.
FOR FURTHER INFORMATION CONTACT: Vincent Osier, Chief, Geographic
Standards and Criteria Branch, Geography Division, U.S. Census Bureau,
via e-mail at [email protected] or telephone at (301) 763-3056.
SUPPLEMENTARY INFORMATION: The Census Bureau's delineation of urban
areas is designed to identify densely developed territory, and
encompass residential, commercial, and other nonresidential urban land
uses. The boundaries of this ``urban footprint'' have been defined
using measures based primarily on population counts and residential
population density, but also through criteria that account for
nonresidential urban land uses, such as commercial, industrial,
transportation, and open space that are part of the urban landscape.
Since the 1950 Census, when densely settled urbanized areas (UAs) of
50,000 or more people were first defined, the urban area delineation
process has addressed nonresidential urban land uses through criteria
designed to account for commercial enclaves, special land uses such as
airports, and densely developed noncontiguous territory.
In delineating urban areas and the resultant classification of
territory outside these urban areas as rural, the Census Bureau does
not take into account or attempt to meet the requirements of any
nonstatistical uses of these areas or their associated data.
Nonetheless, the Census Bureau recognizes that other government
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 purposes should be aware that the changes
to the urban area criteria might affect the implementation of their
programs.
The Census Bureau is not responsible for the use of its urban-rural
classification in nonstatistical programs. If a federal, tribal, state,
or local government agency voluntarily uses the urban-rural
classification in a nonstatistical program, it is that agency's
responsibility to ensure that the classification is appropriate for
such use. In considering the appropriateness of the classification for
use in a nonstatistical program, the Census Bureau urges each
government agency to consider permitting appropriate modifications of
the results of implementing the urban-rural classification specifically
for the purposes of its program. When a program permits such
modifications, the Census Bureau urges each agency to describe and
clearly identify the different criteria being applied to avoid
confusion with the Census Bureau's official urban-rural
classifications.
I. Summary of Changes Made to the 2010 Census Urban Area Criteria
The following table compares the final 2010 Census delineation of
urban areas criteria with the provisions that were proposed in the
August 24, 2010, Federal Register (75 FR 52174).
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Proposed 2010 Census Final 2010 Census
Criteria criteria criteria
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Identification of Initial Census tract and Census tract and
Urban Area Cores. block population block population
density, count, and density, count, and
size thresholds. size thresholds.
Use of National Use of National
Land Cover Database Land Cover Database
to identify to identify
territory with a territory with a
high degree of high degree of
impervious land impervious land
cover. cover.
Inclusion of Noncontiguous Bodies of water and Bodies of Water.
Territory Separated by wetlands as
Exempted Territory. identified in the
National Land Cover
Database.
Inclusion of Noncontiguous Maximum hop distance Maximum hop distance
Territory via Hops and 0.5 miles, maximum 0.5 miles, maximum
Jumps. jump distance 2.5 jump distance 2.5
miles, and no hops miles, and no hops
after jumps. after jumps.
Solicited comment
on returning to the
maximum jump
distance of 1.5
miles implemented
for pre-Census 2000
delineations.
Inclusion of Enclaves....... Two types of Two types of
enclaves are enclaves are
identified when identified when
surrounded solely surrounded solely
by qualifying land by qualifying land
territory, and one territory, and one
type of enclave can type of enclave can
be included when be included when
surrounded by both surrounded by both
land that qualified land that qualified
for inclusion in for inclusion in
the urban area and the urban area and
water. water.
[[Page 53031]]
Splitting Large Urban The urban The agglomeration
Agglomerations. agglomeration consists of
encompasses at urbanized areas
least 1,000,000 defined separately
people. Split for Census 2000.
occurs at the Split location is
metropolitan guided by location
statistical area of Census 2000
boundary (or urbanized area
metropolitan New boundaries.
England city and Potential split
town area), and locations will also
compensates for consider
incorporated place metropolitan
and census statistical area,
designated place county, place, and/
boundaries to or minor civil
attempt to avoid division boundaries
splitting places as well as distance
between urban areas. from each component
urbanized area.
Merging Individual Urban N/A................. Merge qualifying
Areas. territory from
separately defined
2010 Census urban
cores that share
territory contained
within the
boundaries of the
same Census 2000
urban area. Merge
only occurs if an
area is at risk of
losing urbanized
area or urban
status and is
preventable by the
merge.
Inclusion of Indentations... 5 square mile 3.5 square mile
maximum area of the maximum area of the
territory within territory within
the indentation to the indentation to
be added to the be added to the
urban area. urban area.
Inclusion of Airports....... Annual enplanement Currently
of at least 2,500 functioning airport
passengers and be with an annual
contiguous to the enplanement of at
urban area. least 2,500
passengers and is
within 0.5 miles to
the urban area.
Additional Nonresidential N/A................. Inclusion of groups
Urban Territory. of census blocks
with a high degree
of impervious
surface and are
within 0.25 miles
of an urban area.
Assigning Urban Area Titles. Clear, unambiguous Clear, unambiguous
title based on title based on
commonly recognized commonly recognized
place names derived place names derived
from incorporated from incorporated
places, census places, census
designated places, designated places,
minor civil minor civil
divisions, and the divisions, and the
Geographic Names Geographic Names
Information System. Information System.
Minimum Population Residing At least 1,500 At least 1,500
Outside Institutional Group persons must reside persons must reside
Quarters. outside outside
institutional group institutional group
quarters for the quarters for the
area to qualify as area to qualify as
its own urban area. its own urban area.
Density Criteria for Census blocks on N/A.
Military Installations. military
installations with
2,500 or more
persons are
automatically given
a population
density of 1,000
persons per square
mile; census blocks
between 1,000 and
2,500 population
are automatically
given a population
density of 500
persons per square
mile.
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Throughout this Federal Register Notice and the urban area criteria for
the 2010 Census, the Census Bureau uses the term ``contiguous'' where
the term ``adjacent'' was used in the proposed 2010 urban area
criteria.
II. History
Over the course of more than a century of 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, but with the
additional allowances to classify certain New England towns and other
areas urban by ``special rule''. 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 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 (UA) concept for the 1950 Census. At that time, the Census Bureau
formally recognized that densely settled communities outside the
boundaries of large incorporated municipalities were just as ``urban''
as the densely settled population inside those boundaries and the large
unsettled or sparsely settled areas inside those boundaries were just
as ``rural'' as those outside. Due to the limitations in technology for
calculating and mapping population density, delineation of UAs was
limited to cities of at least 50,000 people (in the 1940 Census) and
their surrounding territory. The geographic units used to analyze
settlement patterns were enumeration districts (similar to census block
groups), but to facilitate and ease the delineation process, each
incorporated place was analyzed as a single unit--that is, the overall
density of the place was calculated and if it met the minimum
threshold, it was included in its entirety in the UA. Outside UAs,
``urban'' was still defined as any place with a population of at least
2,500. The Census Bureau recognized the need to identify distinct
unincorporated communities existing outside the UAs, and thus created
the ``census designated place'' (CDP) \1\ and designated those with
populations of at least 2,500 as urban.
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\1\ A CDP is a statistical geographic entity encompassing a
concentration of population, housing, and commercial structures that
is clearly identifiable by a single name, but is not within an
incorporated place. CDPs are the statistical geography counterparts
of incorporated places.
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Starting with the 1960 Census and continuing through the 1990
Census, the Census Bureau made a number of changes to the methodology
and criteria for defining UAs, but retained the 1950 Census basic
definition of ``urban'' which was defined as UAs with a population of
50,000 or more and defined primarily on the basis of population
density, as well as places with a population of 2,500 or more located
outside UAs. The enhancements made by the Census Bureau to the
methodology and criteria used during this period included:
[[Page 53032]]
(1) Lowering, and eventual elimination, of minimum population
criteria for places that formed the ``starting point'' for delineating
a UA. This made recognition of population concentrations independent of
the size of any single place within the concentration.
(2) Identification of ``extended cities''--incorporated places
containing substantial amounts of territory with very low population
density, which were divided into urban and rural components using 100
persons per square mile (ppsm) as the density criterion. This kept the
extent of urban territory from being artificially exaggerated by
sparsely settled and overbounded incorporated places.
(3) Implementation for the 1990 Census of nationwide coverage by
census blocks, and use of interactive analysis of population density
patterns at the census block level, or by groups of blocks known as
``analysis units,'' using Census Bureau-developed delineation software.
This enhancement allowed greater flexibility when analyzing and
defining potential UAs, as opposed to using enumeration districts and
other measurement units defined prior to decennial census data
tabulation.
(4) Implementation of qualification criteria for incorporated
places and CDPs for inclusion within a UA based on the existence of a
densely populated ``core'' containing at least fifty percent of the
place's population. This eliminated certain places from the urban area
classification because much of their population was scattered rather
than concentrated.
For the 2000 Census (Census 2000), the Census Bureau took advantage
of technological advances associated with geographic information
systems (GIS) and spatial data processing to classify urban and rural
territory on a more consistent and nationally uniform basis than had
been possible previously. Rather than delineating urban areas in an
interactive and manual fashion, the Census Bureau developed and
utilized software that automated the examination of population
densities and other aspects of the criteria. This new automated urban
area delineation methodology provided for a more objective application
of criteria compared to previous censuses in which individual
geographers applied the urban area criteria to delineate urban areas
interactively. This new automated approach also established a baseline
for future delineations to enable the Census Bureau to provide
comparable data for subsequent decades.
Changes for Census 2000
The Census Bureau adopted six substantial changes to its urban area
criteria for Census 2000:
(1) Defining urban clusters. Beginning with Census 2000, the Census
Bureau created and implemented the concept of an urban cluster. Urban
clusters (UCs) are defined as areas of at least 2,500 and less than
50,000 persons using the same residential population density-based
criteria as applied to UAs. This change provided for a conceptually
consistent, seamless classification of urban territory. For previous
censuses, the lack of a density-based approach for defining urban areas
of less than 50,000 persons resulted in underbounding of urban areas
where densely settled populations existed outside place boundaries or
overbounding when cities included territory with low population
density. Areas where annexation had lagged behind expansion of densely
settled territory, or where communities of 2,500 up to 50,000 people
were not incorporated and were not defined as CDPs, were most affected
by the adoption of density-based UCs. As a result of this change, the
Census Bureau no longer needed to identify urban places located outside
UAs for the purpose of its urban-rural classification.
(2) Disregarding incorporated place and CDP boundaries when
defining UAs and UCs. Taking place boundaries into account in previous
decades resulted in the inclusion of territory with low population
density within UAs when the place as a whole met minimum population
density requirements, and excluded densely settled population when the
place as a whole fell below minimum density requirements.
Implementation of this change meant that territory with low population
density located inside place boundaries (perhaps due to annexation, or
the way in which a CDP was defined) no longer necessarily qualified for
inclusion in an urban area. However, it also meant that nonresidential
urban land uses located inside a place's boundary and located on the
edge of an urban area might not necessarily qualify to be included in a
UA or UC.
(3) Adoption of 500 persons per square mile (ppsm) as the density
criterion for recognizing some types of urban territory. The Census
Bureau adopted a 500 ppsm population density threshold at the same time
that it adopted its automated urban area delineation methodology. This
ensured that census blocks that might contain a mix of residential and
nonresidential urban uses, but might not have a population density of
at least 1,000 ppsm, could qualify for inclusion in an urban area. For
the 1990 Census, geographers could interactively modify analysis units
to include census blocks with low population density that might contain
nonresidential urban uses, while still achieving an overall population
density of at least 1,000 ppsm. Adoption of the lower density threshold
facilitated use of the automated urban area delineation methodology,
and provided for comparability with the 1990 methodology. This change
did not result in substantial increases to the extent of urban areas.
(4) Increase in the jump distance from 1.5 to 2.5 miles. The Census
Bureau increased the jump distance from 1.5 to 2.5 miles. A ``jump'' is
the distance across territory with low population density separating
noncontiguous qualifying territory (area of high population density)
from the main body of an urban area. The increase in the jump distance
was a result of changing planning practices that led to the creation of
larger clusters of single-use development. In addition, research
conducted prior to Census 2000 showed that some jumps incorporated in
UA definitions in 1990 were actually longer than 1.5 miles as a result
of the subjective identification of the gap in developed territory. As
used in previous censuses, only one jump was permitted along any given
road connection.
(5) Introduction of the hop concept to provide an objective basis
for recognizing small gaps within qualifying urban territory. For
Census 2000, the Census Bureau officially recognized the term ``hops,''
which is defined as gaps of 0.5 mile or less between qualifying urban
territory. Hops are used primarily to account for territory in which
planning and zoning processes resulted in alternating patterns of
residential and nonresidential development over relatively short
distances. This provided for a more consistent treatment of short gaps
with low population density, some of which had been treated as jumps in
the 1990 urban area delineation process (and not permitted if
identified as a second jump), while others were interpreted as part of
the pattern of urban development and grouped with contiguous, higher
density blocks to form qualifying analysis units.
(6) Adoption of a zero-based approach to defining urban areas. The
urban area delineation process in previous censuses had generally been
an additive process, where the boundary of a UA from the previous
census provided the starting point for review for the next census. The
changes made for Census 2000 were substantial enough to warrant
[[Page 53033]]
the Census Bureau to re-evaluate the delineation of all urban areas as
if for the first time, rather than simply making adjustments to the
existing boundary. The Census Bureau adopted this zero-based approach
to ensure that all urban areas were nationally defined in a consistent
manner.
The six changes described above represent the major modifications
implemented for Census 2000. They illustrate a substantial shift in
approach adopted by the Census Bureau in its procedure for delineating
urban areas. The availability of new datasets and continued research
since Census 2000 showed the potential for further improvements for the
2010 Census.
III. Summary of Comments Received in Response to Proposed Criteria
The notice published in the August 24, 2010 Federal Register (75 FR
52174) and requested comments on proposed criteria for the 2010 Census
urban areas. In response, the Census Bureau received 179 comment
letters from regional planning and nongovernmental organizations,
municipal and county officials, Members of Congress, state governments,
federal agencies, and individuals.
Comments Pertaining to Proposed Criteria for Splitting Large Urban
Agglomerations
The proposed criteria for splitting large agglomerations formed
during the delineation process drew the largest number of comments. Of
the 179 responses received, 160 commented on the proposed criteria for
splitting large agglomerations. Of these, 102 commenters expressed
concern about the potential merger of specific pairs of urban areas,
with 87 commenters expressing concern about the impact on planning and
policymaking as well as the potential loss of federal funding as a
result of the loss of individual UA status. Other commenters expressed
concern about the loss of local control over funding allocation and
policy decisions, lack of consistency with the Census 2000 urban
classification, and loss of meaningful data.
Twenty-five commenters supported splitting large urban
agglomerations along metropolitan statistical area boundaries or (in
New England) New England city and town area (NECTA) boundaries. Ten
also supported the proposal to avoid splitting incorporated places and
CDPs between urban areas. Six of the comments suggested splitting urban
areas along NECTA Division in New England where available or Primary
Metropolitan Statistical Area boundaries (although the latter are no
longer defined by the Office of Management and Budget). Thirteen
commenters specifically suggested basing the urban agglomeration splits
on the location of the current urban area boundaries; those commenters
who expressed favor for maintaining separate UA status for areas
identified as part of potential agglomerations can be assumed to favor
splitting along Census 2000 UA boundaries. Five commenters advocated
the use of commuting data to determine how and where to split large
agglomerations. Twenty-six commenters favored splitting urban
agglomerations within metropolitan statistical areas, with some
wondering whether the lack of such a provision in the proposed criteria
was an oversight.
The Census Bureau received sixty-five comments regarding the
minimum population threshold to identify which urban agglomerations
should be split. Of these, six commenters favored the proposed
1,000,000 person threshold. Thirty commenters favored a 250,000 person
threshold and eleven commenters suggested keeping the 50,000 person
threshold implemented for the Census 2000 delineation. Among other
suggested minimum population thresholds, commenters also suggested
using a threshold consistent with Federal Transit Administration and
Federal Highway Administration funding thresholds, or no minimum
population threshold at all.
In addition to requests for clarification, the Census Bureau also
received comments expressing concern about the arbitrary nature of the
proposed criteria for splitting and merging urban areas as well as a
lack of local input. Other suggestions include the identification of
combined urban areas through commuting patterns, examining each urban
agglomeration individually to determine the location of each split
boundary, defining agglomeration splits along county and sub-county
boundaries, and retaining the current split boundaries defined for the
Census 2000 delineation.
In response to the comments regarding criteria for splitting large
agglomerations, the Census Bureau will adopt criteria ensuring that
urbanized areas defined for Census 2000 continue to be identified as
separate urbanized areas for the 2010 Census, but only if these areas
continue to qualify as urbanized under the 2010 urban area delineation
criteria. The boundary used to split large agglomerations will be based
on the locations of Census 2000 urban area boundaries. To the extent
possible, this will facilitate continuity and comparability between the
Census 2000 and the 2010 Census urban area definitions.
Comments Pertaining to Proposed Hop and Jump Criteria
The Census Bureau received seventy-five comments regarding the
proposed hop and jump criteria designed to include noncontiguous, but
qualifying territory within an urban area. Of these, forty commenters
suggested lowering the maximum jump distance threshold from 2.5 to 1.5
miles. These commenters suggested that, in addition to preventing the
consolidation of functionally separate urban areas, a shorter maximum
jump distance would improve the overall delineation by preventing
inclusion in the urban area of long stretches of qualifying territory
that are more appropriately classified as rural, especially with the
presence of large expanses of exempted territory and long distance
commuting patterns. Further, one commenter expressed concern that
retaining the existing 2.5-mile maximum jump threshold indicates that
the Census Bureau has moved away from a morphological concept of urban
towards one based on function relationships.
Thirty-three commenters favored no change to the 2.5 mile maximum
jump distance threshold. Reasons for retention of the 2.5 mile maximum
jump distance provided by these commenters included retaining
consistency with the Census 2000 urban area delineation, the ability to
account for future urbanization and extended suburbanization, and
mitigation of the presence of undevelopable land not identified by the
Census Bureau. One commenter suggested that the 2.5 maximum jump
distance allowed is too restrictive in coastal areas where large areas
of wetlands are present, even if such territory is identified as
exempted. One commenter suggested different maximum jump thresholds
should be applied to urban areas of different population sizes, with
longer jumps allowed for larger initial urban cores.
Three commenters expressed concern that the proposed criteria do
not allow for a second iteration of hops after jumps; one commenter
agreed with the proposal to not allow hops after a jump had been made.
Two commenters requested clarification on the sequence of hops and
jumps in relation to the identification of airports, wondering whether
it is possible to hop or jump from an urban area to additional
qualifying territory if airports are included in the urban area after
the hop and jump criteria have been implemented. One commenter
suggested that all intervening census
[[Page 53034]]
blocks separating an initial urban core and its noncontiguous
qualifying territory must have a minimum population density of at least
500 ppsm. One commenter suggested not allowing multiple hops, and
another opposed including any noncontiguous densely settled territory
via hops and jumps.
Based on the comments received as well as a general desire to
maintain comparability between the Census 2000 and 2010 Census
criteria, the Census Bureau will continue to use the maximum jump
distance of 2.5 miles, as well as the maximum hop distance of 0.5
miles. The Census Bureau notes that the comments pertaining to the
maximum distance of a jump did not strongly favor either retention of
the 2.5-mile maximum jump distance implemented for the Census 2000 or
reversion to the 1.5 mile maximum of previous decades. In response to
concerns that application of the hop and jump criteria allows urban
areas to reach too far into rural territory, the Census Bureau will not
allow for a second iteration of hops after a jump. The Census Bureau
will also retain the proposed requirement for an overall density of at
least 500 ppsm for all noncontiguous qualifying territory (both the
high density destination and intervening territory).
Comments Pertaining to Proposed Criteria for Identifying and Linking
Across Exempted Territory
The Census Bureau received thirty-three comments pertaining to the
proposed criteria for recognizing territory in which urban development
is constrained due to either topographic or land cover/land use
conditions during the inclusion of noncontiguous, but qualifying urban
territory. Sixteen commenters agreed with the proposed criteria to
identify wetlands as exempted territory in addition to water features,
national parks, and national monuments as was done for the Census 2000
delineation. Five of these commenters, however, suggested that wetlands
only be identified as exempt if the maximum jump distance was lowered
to 1.5 miles. In addition to identifying wetlands as exempted
territory, five commenters suggested additional classes of land cover
restricting development, such as farmland, forested land, conservation
easement properties, and steeply sloped territory in which mountain
passes are present. Although still in agreement with the identification
of wetlands as exempted territory, commenters expressed additional
concerns regarding the vintage of the 2001 National Land Cover Database
(NLCD) developed by the Multi-Resolution Land Characteristics
Consortium (MRLC) \2\ and suggested using the NLCD 2006 update as well
as incorporating additional wetlands datasets based on ground-truth
samples, more current imagery, and/or projection models, and locally
produced surface data where available. Commenters also expressed
concern about the objectivity in determining whether these territories
will not be developed as well as not be included in the overall
population density calculation of urban areas.
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\2\ The NLCD includes data for the entirety of the United
States, Puerto Rico, and the U.S. Virgin Islands.
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Five commenters opposed the identification of wetlands as exempted
territory, citing NLCD data vintage and quality, the compatibility of
the NLCD to data within the Census Bureau's Master Address File/
Topologically Integrated Geographic Encoding and Referencing (MAF/
TIGER) database (MTDB), lack of local input in defining wetlands, and
the proper vetting of NLCD prior to inclusion in the criteria as issues
of concern. Commenters also suggested that the combination of wetlands
and water features as exempted territory with a 2.5-mile maximum jump
distance threshold exaggerates the amount of urban territory defined
and noted that only considering wetlands as exempted does not account
for other types of land cover/uses that act as barriers to urban
development. One commenter also questioned how close wetlands territory
must be to road segments as well as why it is necessary to be located
on both sides of the road, to be considered exempted territory.
The Census Bureau received three comments opposing the
identification of water features as exempted territory suggesting that
wide expanses of water should clearly separate urban areas. One
commenter suggested the use of Radio Detection And Ranging (RADAR)
mapping to better identify water landscape features as exempted
territory. Three commenters opposed the identification of all exempted
territory in the urban area delineation criteria. These commenters
suggested that the exempted territory criteria allow for the extension
of urban areas across county boundaries, which is counter to the
overall intent for defining urban areas by the Census Bureau. Note that
the Census Bureau's urban area criteria have always allowed for the
extension of urban area boundaries across the county boundaries. Other
commenters suggested adding floodplains, regional parks, national
wildlife areas, steeply sloped terrain, and other defined open space
with restricted development properties as exempted territory classes.
In response to the comments received, the Census Bureau will
continue to take into account exempted territory when delineating urban
areas, as it has for several decades. The Census Bureau will also
continue to only consider conditions where exempted territory is on
both sides of a road, otherwise development would not be fully
constrained. However, based on concerns raised by commenters and to
maintain decennial comparability, for the 2010 Census urban area
delineation, bodies of water included in the Census Bureau's MTDB will
be the only specific class of territory identified as exempted. Similar
to the Census 2000 delineation criteria, additional exempted territory
will include land area in which the populations of the census blocks on
both sides of a road segment are zero and the road connection crosses
at least 1,000 feet of water. This methodology is designed to identify
unpopulated wetlands and floodplains adjacent to water that separate
areas of urban development. Nonetheless, the Census Bureau decided to
break from the Census 2000 delineation criteria by not considering
national parks and national monuments as exempted territory because of
concerns regarding the data quality and vintage. The Census Bureau also
decided not to include any of the proposed wetlands classes in the
category of exempted territories. The presence of large expanses of
wetlands territory coupled with a maximum jump distance threshold of
2.5 miles would facilitate the over extension of urban territory in
certain locations around the nation. The consideration of wetlands as
exempted territory imparts a regional bias to the delineation process
due to the greater prominence of wetlands in some parts of the country,
such as the southern and southeastern United States. The Census Bureau
has decided against adding additional classes of exempted territory
until a larger and more robust category of land cover/land use types
acting as barriers to urban development can be identified consistently
and uniformly for the entire United States and Puerto Rico.
Comments Pertaining to Proposed Criteria To Qualify Territory
Containing a High Degree of Impervious Surface Land Cover
Twenty-three commenters responded to the proposed use of the NLCD
to assist in identifying and qualifying as urban, sparsely populated
urban-related territory associated with a high degree
[[Page 53035]]
of impervious surface land cover. Eighteen comments favored adoption of
the proposal to qualify territory based on the percentage of impervious
surfaces. Ten commenters, however, expressed concern about the vintage
of the data, questioning the relevance of using the 2001 NLCD as it is
more representative of urban conditions at the time of Census 2000 and
does not account for subsequent development. Commenters suggested using
the NLCD 2006 update, supplemental land cover/land use datasets based
on ground-truth samples, more current imagery, and/or projection
models, as well as local opinion and locally produced surface data,
where available. Five commenters who favored using impervious surface
data conditioned their support on the premise that the maximum jump
distance threshold should revert to 1.5 miles to prevent the over
extension of urban territory. Other commenters expressed concern about
the overall quality of the NLCD, how well these data match data in the
MTDB, that introduction of these data were not properly vetted, and
requested that the Census Bureau provide public products merging
impervious surface data with information for census blocks.
After considering the comments received, the Census Bureau, as
described in the proposed criteria, will include impervious surface
data when delineating urban areas as a means to identify business
districts, commercial, and industrial zones, located both on the edge
and in the interior of an urban area that would not qualify as urban
based on residential population measures alone. In response to the
comments, the Census Bureau will use the 2006 NLCD update wherever
available and will use the 2001 NLCD in areas of the Nation not yet
covered by the 2006 NLCD update in its efforts to promote a more
publicly replicable urban area delineation. For the 2010 Census urban
area delineation, the most consistent, comprehensive, and accessible
impervious surface database for the United States and Puerto Rico is
the NLCD.
Comments Pertaining to Proposed Use of Census Tracts as Building Blocks
The Census Bureau received twenty-one comments regarding the
proposed use of the census tract as the analysis unit (or geographic
building block) during the delineation of the initial urban area core.
Of these, sixteen commenters favored the proposal. Three commenters
also supported the use of census tracts as analysis units, but
suggested modifications to the initial urban core delineation criteria.
These commenters expressed concern that the minimum population density
threshold of 500 ppsm was too high, proposed increasing the maximum
land area threshold to four square miles, and suggested applying the
Census 2000 block group-based delineation criteria after using census
tracts as analysis units to capture lower density territory in
mountainous areas resulting from census geography primarily being
defined along visible features. The two letters opposing the use of
census tracts as analysis units both questioned the relevance of this
criterion when delineation of initial urban cores also occurs at the
census block level. An additional concern was about the reduced
population density measurements resulting from the inclusion of water
area in census tracts (although population density is based only on
land area). One letter requested clarification on the iterative nature
of the initial urban core building process once the delineation
criteria moves down to the census block level.
In response to the comments received regarding these criteria, the
Census Bureau will replace census block groups with census tracts as
the analysis unit during the delineation of the initial urban area core
for the 2010 Census urban area delineation as described in the proposed
criteria. Changing the urban area core delineation analysis unit to the
census tract offers advantages of increased consistency and
comparability, since census tracts are more likely to retain their
boundaries over the decades than census blocks and block groups. The
Census Bureau decided to retain the minimum 500 ppsm threshold to
maintain comparability with the Census 2000 urban area delineation.
This population density threshold was chosen to allow the Census Bureau
to account for the inclusion of open space and other nonresidential
urban uses within census tracts and blocks that also contain
residential development. The Census Bureau also decided not to adopt
the suggested maximum census tract size criterion of four square miles
and to include a maximum census tract size criterion of three square
miles to avoid adding large amounts of sparsely settled territory to
urban areas. Water area, as depicted in the Census Bureau's MTDB, has
never been included in population density calculations for the urban
area delineation program.
Research by the Census Bureau has indicated that the initial urban
cores tend to experience slight decreases in territory and only slight
increases in population qualifying as urban when the initial analysis
unit is changed from the block group to the census tract. The small
reduction in initial urban area core territory is due to the use of
census tracts, which are larger geographic units and therefore less
likely than block groups to qualify under the density requirements.
Similar to the way block groups were used for Census 2000, if a census
tract does not meet specified area measurement and density criteria,
the focus of analysis will shift to individual census blocks within the
tract, and delineation will continue at the block level. As a result,
when using census tracts, the delineation process shifts to census
block-level analysis sooner than would be the case when using block
groups. This methodology is iterative as additional qualifying census
tracts and blocks are added to the initial urban core until no such
qualifying territory exists during this phase of the delineation.
Comments Pertaining to Proposed Criteria for Inclusion of Enclaves and
Indentations
The Census Bureau received six comments regarding proposed criteria
for inclusion of territory in indentations and enclaves formed during
the delineation process. Three commenters supported the proposed
criteria for including indentations, by way of criteria similar to
those implemented for the Census 2000, citing the jagged nature of the
current urban area boundaries. Conversely, one commenter opposed the
indentation criteria if the only purpose was to produce a more
cartographically pleasing depiction of boundaries. One commenter
suggested modifying the enclave criteria by lowering the maximum area
threshold of five square miles and requiring the majority of the
enclave boundary to border territory qualifying as urban. One commenter
questioned if these criteria are still necessary.
In response to the comments received regarding the criteria for the
inclusion of enclaves and indentations, the Census Bureau decided not
to make any changes to the proposed enclave and indentation criteria to
maintain comparability from one decade to another. In situations where
an enclave is identified and is contiguous to both qualifying territory
and a water feature, the territory within the enclave can only be
captured if the line of contiguity with the qualifying territory is
greater than the line of contiguity with the water feature. These
criteria are designed to qualify internal and fringe territory that may
not qualify as urban due to large census blocks with a substantial
presence of open space (parks, golf
[[Page 53036]]
courses, etc.) but should be considered part of the urban footprint.
Comments Pertaining to Proposed Criteria for Inclusion of Airports
The Census Bureau received ten comments pertaining to the proposed
criteria for including airports in urban areas; all ten agreed with the
proposal to include census blocks in their entirety approximating the
territory encompassed by major airports. One commenter, however,
disagreed with the proposal to lower the minimum enplanement threshold
to 2,500 passengers, noting that commercial hubs are better represented
than facilities with a mixture of charter or business flights and
joint-use (military/general aviation) airports according to commercial
enplanements only. This commenter also suggested that the criteria
should take into consideration the number of flights. Two commenters
favored the inclusion of cargo flights in addition to general aviation
enplanements when identifying airports according to the minimum
enplanement threshold. Another commenter noted that more recent
enplanement data (2009) are available through the Federal Aviation
Administration (FAA) than were referenced in the proposed criteria.
Additional comments included requests for data content clarification
such as whether the data include commercial only, military activities,
or all enplanements, as well as whether the Census Bureau will consider
cargo weight in identifying major airports. The Census Bureau also
received one comment requesting the recognition of rail yards, sea
ports, and utilities facilities as qualifying as urban territory in
addition to airports.
Upon considering the comments received, the Census Bureau will
retain the Census 2000 criteria to include whole census blocks
representing airports in urban areas. In order to qualify, an airport
must report a minimum annual enplanement of 2,500 passengers as
reported by the FAA for at least one calendar year from 2001 to the
most current data available for the delineation. All identified
airports must be currently in service and providing services for the
urban area in which it is to be included. The 2,500 passenger threshold
was chosen to provide for a more complete coverage of airports,
particularly those near smaller initial urban cores. The annual
passenger boarding data will include only commercial service
enplanements (primary and nonprimary) to promote consistency with the
Census 2000 urban area criteria as well as to facilitate a more
replicable delineation. Also in accordance with the Census 2000
delineation, the inclusion of airports will represent the last step in
identifying qualifying urban territory. However, upon further
consideration and review of data, the Census Bureau has decided to also
include airports within 0.5 miles of the urban area. This process
simulates the connection of noncontiguous qualifying territory via the
hop criteria. All other urban land cover/land use not qualifying
through residential population count and density measures will be
represented through the enclave and indentation criteria designed for
the Census 2000 delineation and supplemented with the impervious
surface data introduced for the 2010 Census.
Comments Pertaining to the Proposed Criterion Requiring at Least 1,500
Persons Residing Outside Institutional Group Quarters for an Area To
Qualify as an Urban Area
Five commenters supported the proposed criterion requiring that an
area must encompass at least 1,500 persons living outside institutional
group quarters (GQs) in order to qualify as an urban area. Two
commenters opposed this criterion, with one stating that an urban area
should qualify only on the basis of population residing outside group
quarters and the other suggesting that qualification as an urban area
should be based on total population without distinction based on status
within institutional group quarters. One commenter requested that the
Census Bureau more closely examine the nature of the land use
associated with large group quarters before disqualifying territory as
urban as it contradicts the proposed criteria relating to population
density and impervious surfaces.
In response to the comments received, the Census Bureau is
finalizing the provision that all qualifying urban areas must encompass
at least 1,500 persons living outside institutional GQs without change
to avoid the delineation of an urban area comprising only a few census
blocks in which an institutional GQ was located. The Census Bureau
recognizes that although the population densities of these areas exceed
the minimum thresholds specified in the urban area criteria, and the
total populations exceed 2,500, they lack most of the residential,
commercial, and infrastructure characteristics typically associated
with urban territory.
Comments Pertaining to the Proposal to Eliminate the Central Place
Concept
The Census Bureau received nine comments regarding the proposed
elimination of the central place concept from the urban area
delineation criteria. Eight commenters agreed with the proposal. The
one commenter who disagreed requested that the Census Bureau should
continue to identify central places until it is clear that the
elimination of these criteria will not impact the designation of
principal cities of metropolitan and micropolitan statistical areas.
In response to the comments received, the Census Bureau is
finalizing its proposal to discontinue identifying central places as
part of the 2010 Census urban area delineation process. The Census
Bureau notes that the identification of central places is no longer
necessary for the process of delineating urban areas and can result in
some central places being split between urban and rural territory.
Moreover, the Office of Management and Budget (OMB) always had its own
criteria to identify principal cities as part of the metropolitan and
micropolitan statistical areas program.\3\ The list of principal cities
identified by the OMB is quite similar to what would emerge if the
urban area process created a list of central places. The Census Bureau
no longer sees a need for a second representation of the same concept
in its statistical and geographic data products. Principal cities of
metropolitan and micropolitan statistical areas are identified based on
different set of criteria and as part of the metropolitan and
micropolitan area delineation process. This decision will have no
impact on the metropolitan and micropolitan area delineation process.
---------------------------------------------------------------------------
\3\ See the ``2010 Standards for Delineating Metropolitan and
Micropolitan Statistical Areas,'' Federal Register, 75 FR 37246,
June 28, 2010.
---------------------------------------------------------------------------
Comment Pertaining to the Shape Index Used When Measuring Compactness
of Census Blocks
The Census Bureau received one comment concerning the shape index
proposed to identify census blocks considered compact during the
delineation of the initial urban area cores. This commenter suggested
modifying the compactness criterion to only include those census blocks
that score 0.310 or higher according to the proposed shape index
formula, as opposed to the proposed shape index value of 0.185 or
higher.
The Census Bureau will retain the shape index threshold as
proposed. Internal research and investigation has shown this to be a
reasonable metric for measuring compactness for all census blocks
having the potential to qualify as urban without excluding census
blocks
[[Page 53037]]
that should be included in an urban area.
Comments Pertaining to the Nonstatistical Uses of Urban Area
Delineations
Seventeen commenters expressed concern that the Census Bureau does
not acknowledge or consider any nonstatistical uses of urban areas when
developing delineation criteria. Thirteen of these commenters suggested
that the Census Bureau initiate an inter-agency task force to identify
the potential negative impacts, particularly on federal funding,
resulting from changes to the urban area delineation criteria, and
design mitigation measures and/or solutions to these issues if the
proposed changes were implemented. These commenters also suggested
delaying the delineation of urban areas until provisions are adopted
that would prevent adverse impacts on programs and funding formulas
relating to urban areas as currently defined.
Nine commenters stressed the importance of consistency in both
urban area delineation criteria and status from one decade to another
to aid long-term planning and policy making. Five of these commenters
specifically requested that territory defined as urban in Census 2000
continue to be defined as urban for the 2010 Census.
Five commenters expressed concern that there are no provisions in
the delineation criteria for local input and requested the opportunity
to review and comment on the definition of urban areas before
boundaries become final. These commenters also expressed concern about
the automated and inflexible nature of the delineation process and
suggested that the extent of each urban area should be evaluated
individually. The Census Bureau also received two comments expressing
concern that the proposed delineation criteria do not take into account
local zoning laws and incorporated place boundaries.
Two commenters criticized the timing for developing the urban area
delineation criteria. These commenters stated that the methodology is
flawed because projections related to potential changes in the
delineation criteria are based on Census 2000 data and geography. These
commenters suggested that the Census Bureau should delay development of
the proposed delineation criteria until after 2010 Census data and
geography become available.
The Census Bureau received eight requests for the extension of the
public comment period on the proposed urban area delineation criteria
to further assess its potential impacts. Additional comments expressed
difficulty in predicting results of changes to criteria as published in
the August 24, 2010 Federal Register (75 FR 52174), and requested
clarification of the proposed urban area delineation criteria.
Commenters also submitted requests for real-world examples of how
changes to the urban area delineation criteria would manifest on the
landscape, maps of the proposed urban areas, and access to the
delineation software to facilitate better informed public comment.
In response to the comments received regarding the nonstatistical
uses of Census urban areas, 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 Census Bureau remains
committed to an objective, equitable, and consistent nationwide urban
area delineation, and thus identifies these areas solely for the
purpose of tabulating and presenting statistical data. This provides
data users, analysts, and agencies with a baseline set of areas from
which to work, as appropriate. Given the many programmatic and often
conflicting or competing uses for Census Bureau-defined urban areas,
the Census Bureau cannot attempt to take each program into account.
Therefore, by not taking any one nonstatistical use into account, the
Census Bureau does not favor one program over another. The Census
Bureau's designations are used to identify areas to receive funding for
urban programs and also to identify areas for exclusion from rural-
based programs.
In building upon the Census 2000 urban area criteria, the Census
Bureau is developing urban area criteria for the 2010 Census consisting
of a single set of rules that allow for application of automated
processes based on the input of standardized nationwide datasets that
yield consistent results. Rather than defining areas through a process
of accretion over time, the criteria also provide a better reflection
of the redistribution of population and how it affects the current
state of urbanism. This can be done only by reexamining all territory
that qualified as either urban or rural in earlier censuses based on
different criteria, geography, and population distribution patterns as
measured by those censuses. Nonetheless, the Census Bureau will apply
urban agglomeration split and individual urban area merge criteria to
ensure, to the greatest extent possible, the continued existence of all
urbanized areas defined for the Census 2000; although the actual urban
territory these areas comprise may differ.
The delineation and production of urban areas and their associated
data were scheduled to begin in March 2011, to ensure sufficient time
to delineate and review the urban area definitions and prepare
geographic information files in time to tabulate statistical data from
both the 2010 Census and the American Community Survey (ACS). Adherence
to this schedule prevented any attempts toward a test delineation using
all of the proposed 2010 urban area criteria for the entire United
States and Puerto Rico, thus prohibiting the availability of real-world
examples without showing preference to any particular location.
Further, this schedule also dictated that the development of the
delineation software coincided with the development of the proposed and
final criteria.
IV. Changes to the Proposed Urban Area Criteria for the 2010 Census
This section of the Federal Register provides information about the
Census Bureau's decisions on changes that were incorporated into the
Urban Area Criteria for the 2010 Census in response to the many
comments received. These decisions benefited greatly from the public
participation, which served as a reminder that, although identified for
purposes of collecting, tabulating, and presenting federal statistics,
the urban areas defined through these criteria represent areas in which
people reside, work, and spend their lives and to which they attach a
considerable amount of local pride. In reaching our decisions, the
Census Bureau took into account the comments received in response to
the proposed criteria published in the Federal Register on August 24,
2010, (75 FR 52174), as well as comments received during webinars,
conference presentations, and meetings with federal, state, and local
officials, other users of data for urban areas, and additional research
and investigation conducted by Census Bureau staff.
The changes made to the proposed criteria in Section II of the
August 24, 2011, Federal Register Notice, ``Proposed Urban Area
Criteria for the 2010 Census,'' are as follows:
1. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' in the introductory paragraph to this section, the Census
Bureau removed the reference to Island Areas in the first sentence
because the Census Bureau, in consultation with government officials in
the Island Areas (American Samoa, Guam, the Commonwealth of the
Northern Mariana Islands, and the U.S.
[[Page 53038]]
Virgin Islands), is still considering whether to identify urban and
rural areas for the Island Areas. Census 2000 was the only census in
which density-based criteria were applied to defining urban areas in
the Island Areas.
2. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' subsection B.1, the Census Bureau corrected the initial urban
area core delineation criteria to better represent the iterative nature
of these criteria. After the initial urban area core with a population
density of 1,000 ppsm or more is identified, additional qualifying
census tracts may be included only if contiguous to other qualifying
census tracts.
3. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' subsection B.1, the Census Bureau removed reference to census
blocks within military installations. Due to imposed restrictions on
the selection of features that could be used as census block boundaries
within military installations for Census 2000, blocks on military
installations that had a population of 2,500 or more were treated as
having a population density of 1,000 ppsm even if the density was less
than 1,000 ppsm. Census blocks that had a population greater than 1,000
and less than 2,500 were treated as having a population density of 500
ppsm. The Census Bureau has removed these criteria as the restrictions
on the selection of features for census block boundaries within
military installations is no longer in effect for the 2010 Census.
4. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' subsection B.1, the Census Bureau clarified references to the
MRLC NLCD data used in determining impervious surfaces during the
delineation of initial urban cores. The Census Bureau has decided to
use the MRLC NLCD 2006 update (recently made available for the
conterminous United States in February 2011) to better represent land
use/land cover conditions at the time of the delineation. The MRLC 2001
NLCD will be used only where the 2006 data are not available.
5. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' subsection B.1, the Census Bureau added criteria to include
in the initial urban core census blocks that are associated with a high
degree of impervious surface land cover and are mostly contiguous to
qualifying territory, but fail the shape index threshold of
compactness. These criteria were added to compensate for the presence
of elongated census blocks defined along road medians, which create
narrow strips of territory not qualifying as urban. Through further
investigation, the Census Bureau found instances where one or more of
these intervening census blocks associated with road medians created a
barrier which prevented nearby qualifying territory from being
considered contiguous. Furthermore, the Census Bureau has decided
census blocks associated with road medians sharing a large degree of
contiguity with qualifying territory should be included in the urban
area.
6. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' subsection B.1, the Census Bureau added reference to describe
the review of the initial urban area cores. In an effort to mitigate
the overextension of territory classified as urban into rural areas,
the Census Bureau will identify census blocks qualifying as urban via
the impervious surface criteria that are added to the initial urban
cores late in the delineation process. The Census Bureau will review
these census blocks located on the edge of an initial urban area core
to determine if their classification as urban is appropriate. This
review will also determine if these late-qualifying census blocks are
elongated or small and consistently qualified when compared to the
relatively large cell size of the impervious surface data.
7. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' subsection B.2, the Census Bureau removed the identification
of wetlands as exempted territory criteria and references to the MRLC's
2001 NLCD wetlands class definitions. The Census Bureau decided to only
consider bodies of water as exempted territory until a more
comprehensive category of land use/land cover classes can be identified
for the entirety of the United States and Puerto Rico. Furthermore,
because the Census Bureau will retain the 2.5 mile maximum jump
distance threshold implemented for the Census 2000, it has decided to
limit the recognition of exempted territories to prevent the over
expansion of urban areas.
8. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' subsection B.2, the Census Bureau added criteria to include
the identification of land area where the populations of the census
blocks on both sides of a road segment are zero and, additionally, the
road connection crosses at least 1,000 feet of water. The Census Bureau
added this criterion to remain consistent with the urban area
delineation criteria implemented for Census 2000.
9. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' subsection B.3, the Census Bureau added a criterion for the
inclusion of noncontiguous territory via hops and jumps to allow stand-
alone census blocks, that are not contiguous to territory that qualify
as part of the initial urban core, but having a population density
greater than or equal to 500 ppsm, to be added to an urban area. This
criterion is designed to include densely settled territory proximate to
the urban fringe within a relatively larger census block that remains
separated from the initial urban area core due to the local road
network configuration. The addition of this criterion is also
consistent with the Census 2000 urban area delineation criteria.
10. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' subsection B.4, the Census Bureau added reference to the data
extracted from the FAA Air Carrier Activity Information System to
clarify the dataset that is to be used in the identification of
airports that are included in urban areas. The Census Bureau has
decided to use data representing annual enplanements for only primary
and nonprimary commercial service facilities as defined by the FAA.
Limiting the enplanement data to commercial service airports offers the
advantage of minimizing the amount of data manipulation required to
identify airports, which in turn facilitates public replication of the
criteria. This also results in consistency with the Census 2000 urban
area delineation criteria.
11. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' subsection B.4, the Census Bureau modified the criteria for
including airports in urban areas by clarifying that the qualifying
airport does not need to be contiguous with an urban area, but rather
within 0.5 miles of the urban area. The Census Bureau changed this
criterion to simulate the connection of noncontiguous qualifying
territory via the hop criterion.
12. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' subsection B.4, the Census Bureau modified the airport
inclusion criteria so that the Census Bureau will only identify
functioning airports at the time of the delineation. This modification
ensures that these criteria will not include an airport if it no longer
services a particular urban area.
13. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' the Census Bureau moved subsection B.4 in its entirety to
follow the criteria for the inclusion of indentations to urban areas
[[Page 53039]]
(subsection B.6). The Census Bureau reordered the delineation criteria
so that the inclusion of airports will represent the last step in
identifying urban territory, as was done for the Census 2000
delineation. Although the airport inclusion criteria do allow for the
qualification of noncontiguous facilities to urban areas, they prohibit
an airport from serving as a source area from which hops and jumps can
originate.
14. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' subsection B.5, the Census Bureau clarified the criteria for
the inclusion of enclaves in urban areas. The criteria distinguish
between the two types of enclaves completely surrounded by qualifying
land territory, and a third enclave type completely surrounded by
qualifying land and nonqualifying water.
15. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' subsection B.6, the Census Bureau modified the maximum area
of the territory within the indentation that is added to the urban area
from less than five square miles to less than 3.5 square miles. The
Census Bureau changed this criterion for the 2010 Census urban area
delineation to reduce the amount of territory qualifying through
indentations without lowering the maximum length of the potential
closure lines.
16. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' the Census Bureau moved subsection B.6 in its entirety to
follow immediately the criteria relating to splitting large
agglomerations and merging of individual urban areas. For Census 2000,
the splitting of large urban agglomerations occurred prior to the
inclusion of indentations to urban areas. Splitting the urban
agglomerations before the addition of urban territory through the
indentation criteria enabled the Census Bureau to better identify where
the corridor of contiguity between urban areas was truly at its
narrowest, which aided in determining the best split location. The
Census Bureau reordered the delineation criteria to remain consistent
with the criteria implemented for the Census 2000.
17. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' the Census Bureau replaced subsection B.7 with a new set of
criteria for splitting large agglomerations based on comments received.
The Census Bureau adopted criteria that will ensure that Census 2000
urbanized areas will continue to be recognized as separate urbanized
areas if these areas continue to qualify as urbanized under the 2010
Census urban area delineation criteria. Adoption of these criteria will
facilitate continuity and comparability between the two decades' urban
definitions.
18. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' the Census Bureau modified subsection B.8, which addressed
the criteria for assigning urban area titles, to allow for more equal
representation of local places if the urban area does not contain a
place with an urban population of at least 2,500 people. This change is
also intended to promote consistency with the Census 2000 criteria for
titling urban areas.
19. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' subsection B, the Census Bureau added new criteria to
identify and qualify additional nonresidential urban-related territory
that is not contiguous with, but near qualifying urban areas. The
Census Bureau added these criteria in its effort to capture large
commercial and/or industrial land uses separated from an urban area by
a relatively small amount of undeveloped territory. As a final review,
the Census Bureau will examine the territory surrounding the urban
areas associated with a high degree of impervious surface land cover
and determine whether they should be included in an urban area.
20. In Section II, ``Proposed Urban Area Criteria for the 2010
Census,'' subsection C, the Census Bureau modified the definitions for
contiguous, exempted territory, group quarters, and impervious surface
to clarify how these key terms relate to the 2010 urban area
delineation criteria. Additional definitions are provided for enclave,
hop, indentation, initial urban area core, institutional group
quarters, jump, and noninstitutional group quarters, all terms used in
the proposed criteria.
21. Throughout this Federal Register Notice and the urban area
criteria for the 2010 Census, the Census Bureau uses the term
``contiguous'' wherever the term ``adjacent'' was used in the proposed
2010 urban area criteria. This change was made for the purposes of
clarity.
The Following Sets Forth the Urban Area Criteria for the 2010
Census.
V. Urban Area Criteria for the 2010 Census
The criteria outlined herein apply to the United States \4\ and
Puerto Rico. The Census Bureau will use the following criteria and
characteristics for use in identifying the areas that will qualify for
designation as urbanized areas and urban clusters for use in tabulating
and presenting data from the 2010 Census, the American Community Survey
(ACS), the Puerto Rico Community Survey, and potentially other Census
Bureau censuses and surveys.
---------------------------------------------------------------------------
\4\ The United States includes the 50 States and the District of
Columbia.
---------------------------------------------------------------------------
A. 2010 Census Urban Area, Urbanized Area, and Urban Cluster
Definitions
For the 2010 Census, an urban area will comprise a densely settled
core of census tracts and/or census blocks that meet minimum population
density requirements, along with contiguous territory containing
nonresidential urban land uses as well as territory with low population
density included to link outlying densely settled territory with the
densely settled core. To qualify as an urban area on its own, the
territory identified according to the criteria must encompass at least
2,500 people, at least 1,500 of which reside outside institutional
group quarters. Urban areas that contain 50,000 or more people are
designated as urbanized areas (UAs); urban areas that contain at least
2,500 and less than 50,000 people are designated as urban clusters
(UCs). The term ``urban area'' refers to both UAs and UCs. The term
``rural'' encompasses all population, housing, and territory not
included within an urban area.
As a result of the urban area delineation process, an incorporated
place or CDP may be partly within and partly outside an urban area. Any
place (incorporated place or CDP) that is split by an urban area
boundary is referred to as an extended place. Any census geographic
areas, with the exception of census blocks, may be partly within and
partly outside an urban area.
All criteria based on land area, population, and population
density, reflect the information contained in the Census Bureau's
Master Address File/Topologically Integrated Geographic Encoding and
Referencing (MAF/TIGER) Database (MTDB) produced for the 2010 Census.
All calculations of population density include only land; water area
contained within census tracts and census blocks are not used to
calculate population density.
B. UA and UC Delineation Criteria
The Census Bureau defines urban areas primarily on the basis of
residential population density measured at the census tract and census
block levels of geography. Two population density thresholds are used
in the delineation of urban areas: 1,000 persons per square mile (ppsm)
and 500 ppsm. The higher threshold is consistent with population
density criteria used in the 1960 Census through 1990 Census urban area
delineation processes; it is used to identify the
[[Page 53040]]
starting point for delineation of individual, potential urban areas and
ensures that each urban area contains a densely settled core area that
is consistent with previous decades' delineations. The lower threshold
was adopted for the Census 2000 process when the Census Bureau adopted
an automated delineation methodology; it provides that additional
territory that may contain a mix of residential and nonresidential
urban uses can qualify for inclusion in an urban area.
1. Identification of Initial Urban Area Cores
The Census Bureau will begin the delineation process by identifying
and aggregating contiguous census tracts, each having a land area of
less than three square miles and a population density of at least 1,000
ppsm. After the initial urban area core with a population density of
1,000 ppsm or more is identified, additional census tracts with a land
area less than three square miles and with a population density of at
least 500 ppsm will be included if contiguous to any qualifying census
tracts. If a qualifying census tract does not exist, then one or more
contiguous census blocks that have a population density of at least
1,000 ppsm are identified and aggregated.
A census block is included in the initial urban area core if it is
contiguous to other qualifying territory, and
a. Has a population density of at least 500 ppsm, or
b. At least one-third of the census block consists of territory
with a level of imperviousness of at least twenty percent,\5\ and is
compact in nature as defined by a shape index. A census block is
considered compact when the shape index is at least 0.185 using the
following formula: I = 4[pi]A/P\2\ where I is the shape index, A is the
area of the block, and P is the perimeter of the block, or
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\5\ The data used to define impervious surfaces are limited to
only those that are included in the MRLC's 2001 NLCD or NLCD 2006
update where available. The Census Bureau has found in testing the
NLCD that territory with an impervious percent less than twenty
percent results in the inclusion of road and structure edges, and
not the actual roads or buildings themselves.
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c. At least one-third of the census block consists of territory
with a level of imperviousness of at least twenty percent, and at least
forty percent of its boundary is contiguous with qualifying
territory.\6\
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\6\ The Census Bureau found in testing with the new 2010 Census
geography that a number of census blocks were associated with a high
degree of impervious surface land cover and contiguous to territory
qualifying as urban, but fail the shape index threshold of
compactness . These elongated census blocks are largely the result
of block boundaries defined along road medians and can artificially
separate qualifying territory that should be considered contiguous.
Where appropriate, these elongated census blocks will be added to
the urban area to maintain contiguity of qualifying territory.
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The Census Bureau will apply criteria 1.a, 1.b, and 1.c above until
there are no census blocks to add to an urban area.\7\ Any ``holes'' or
remaining nonqualifying territory completely contained within an
initial urban area core that is less than five square miles in area
will qualify as urban via the criteria for the inclusion of enclaves
set forth in V.B.4.a.
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\7\ The Census Bureau will identify census blocks qualifying as
urban via the impervious surface criteria that are added to an
initial urban area core during later iterations of the delineation
criteria. These census blocks located on the edge of initial urban
cores will be reviewed to determine if their classification as urban
is appropriate. The Census Bureau will also determine if these
census blocks were added as a result of the relatively large cell
size of the impervious surface data when overlaid with a small or
thin census block.
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2. Inclusion of Noncontiguous Territory Separated by Exempted Territory
The Census Bureau will identify and exempt territory in which
residential development is substantially constrained or not possible
due to either topographic or land use conditions.\8\ Such territory
offsets urban development due to particular land use, land cover,
hydrological, and/or topographic conditions. For the 2010 Census, the
Census Bureau identifies bodies of water as exempted territory.
Additional exempted territory will include land area where the
populations of the census blocks on both sides of a road segment are
zero and the road connection crosses at least 1,000 feet of water.
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\8\ The land cover and land use types used to define exempted
territory are limited to only those that are included in or can be
derived from the Census Bureau's MTDB nationally, consistently, and
with a reasonable level of accuracy.
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Noncontiguous qualifying territory will be added to a core when
separated by exempted territory, provided that:
a. The road connection across the exempted territory (located on
both sides of the road) is no greater than five miles, and
b. The road connection does not cross more than a total of 2.5
miles of territory not classified as exempted (those segments of the
road connection where exempted territory is not on both sides of the
road), and
c. The total length of the road connection (exempt distance and
nonexempt distance) is no greater than five miles for a jump and no
greater than 2.5 miles for a hop.
3. Inclusion of Noncontiguous Territory via Hops and Jumps
Noncontiguous territory that meets the proposed population density
criteria specified in Sections 1.a, 1.b, and 1.c above, but is
separated from an initial urban area core of 1,000 or more people, will
be added via a ``hop'' along a road connection of no more than 0.5
miles. Multiple hops may be made along a single road connection, thus
accounting for the nature of contemporary urban development which often
encompasses alternating patterns of residential and nonresidential land
uses.
After adding territory to an initial urban area core via hop
connections, the Census Bureau will identify all cores that have a
population of 1,500 or more and add other qualifying territory via a
jump connection.\9\ Jumps are used to connect densely settled
noncontiguous territory separated from the core by territory with low
population density measuring greater than 0.5 and no more than 2.5 road
miles. This process recognizes the existence of larger areas of
nonresidential urban uses or other territory with low population
density that do not provide a substantial barrier to interaction
between outlying territory with high population density and the main
body of the urban area. Because it is possible that any given densely
settled area could qualify for inclusion in multiple cores via a jump
connection, the identification of jumps in an automated process starts
with the initial urban area core that has the largest total population
and continues in descending order based on the total population of each
initial urban area core. Only one jump is permitted along any given
road connection, unless the territory being included as a result of the
jump was an initial urban area core with a population of 50,000 or
more. This limitation, which has been in place since the inception of
the urban area delineation process for the 1950 Census, prevents the
artificial extension of urban areas over large distances that results
in the inclusion of communities that are not commonly perceived as
connected to the particular initial urban area core. Exempted territory
is not taken into account when measuring road distances along hop and
jump corridors.
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\9\ All initial urban area cores with a population less than
1,500 are not selected to continue the delineation as separate urban
areas; however, these cores still are eligible for inclusion in an
urban area using subsequent proposed criteria and procedures.
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In addition to the distance criteria listed above, a hop or a jump
will qualify only if:
a. The territory identified in the high-density destination and
along the hop or
[[Page 53041]]
jump corridor has a combined overall population density of at least 500
ppsm, or
b. The high-density destination to be added via the hop or jump has
a total population of 1,000 or more.
Although census blocks with a population density greater than or
equal to 500 ppsm, but less than 1,000 ppsm, and not contiguous to
qualifying territory containing at least one census tract or census
block with a population density of at least 1,000 ppsm do not qualify
as part of the initial urban core, these census blocks may still
qualify as urban via hops or jumps.\10\
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\10\ These isolated census blocks not contiguous to an initial
core remain eligible destinations for either hops or jumps. These
census blocks may be included via the noncontiguous qualifying
territory criteria in an effort to capture proximate densely settled
territory on the urban fringe within a relatively larger census
block that is separated from the initial urban area core.
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4. Inclusion of Enclaves
The Census Bureau will add enclaves (that is, nonqualifying area
completely surrounded by area already qualified for inclusion as urban)
within the urban area, provided that they are surrounded only by land
area that qualified for inclusion in the urban area based on population
density criteria and at least one of the following conditions is met:
a. The area of the enclave must be less than five square miles, or
b. All area of the enclave is surrounded by territory that
qualified for inclusion in the initial core, and is more than a
straight-line distance of 2.5 miles from a land block that is not part
of the urban area.
Additional enclaves will be identified and included within the
urban area if:
c. The area of the enclave is less than five square miles, and
d. The enclave is surrounded by both land that qualified for
inclusion in the urban area and water, and
e. The length of the line of adjacency with the water is less than
the length of the line of adjacency with the land.
5. Splitting Large Agglomerations and Merging Individual Urban Areas
Population growth and redistribution coupled with the automated
urban area delineation methodology that will be used for the 2010
Census may result in large urban agglomerations of continuously
developed territory that may encompass urban areas that were defined as
separate urbanized areas in Census 2000. Conversely, the delineation
methodology may also result in separate urbanized areas that were
previously defined as belonging to a single urbanized area. If such
results occur, the Census Bureau will apply split and merge criteria
guided by the Census 2000 urban area boundaries to the greatest extent
possible to ensure the continued recognition of all such urbanized
areas. All territory subject to either the splitting or merging
criteria must first qualify as urban according to the 2010 Census
delineation criteria.
The rule to retain the inventory of urbanized areas that continue
to separately qualify for the 2010 Census does not apply to urban
clusters. Urban clusters may be merged with other urban areas. The
Census Bureau retains previously separate urbanized areas because these
urban areas have historically developed as the functional units of 50
years of urbanized area delineation. Mandating this rule for urban
clusters would artificially impede these areas from merging to form
urbanized areas.
The Census Bureau will split a large urban agglomeration if the
agglomeration consists of urbanized areas that were defined separately
for the Census 2000. Potential split locations will include territory
not qualifying as urban for the 2010 Census, water features, jump or
hop corridors,\11\ impervious census blocks,\12\ where the corridor of
contiguity between the component urbanized areas is at its most narrow,
other geographic boundaries,\13\ and/or the nearest location to the
midpoint between the two component urbanized areas. In all cases, the
Census Bureau will split the urban agglomeration at the best possible
location that ensures the continued existence of all urbanized areas
defined for the Census 2000.
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\11\ The Census Bureau will remove the jump or hop connection if
the component urban areas are connected via the noncontiguous
qualifying territory criteria.
\12\ The Census Bureau may remove the entire connection in cases
where urban areas are only contiguous via elongated census blocks
qualifying as urban and associated with road medians. The connection
will remain intact in situations where additional impervious census
blocks are present.
\13\ In situations where an incorporated place, CDP, or minor
civil division crosses the Census 2000 urbanized area boundary, the
2010 urbanized area boundary may be modified to follow these
boundaries if it is deemed that territory qualifying as urban
belongs more to a particular urbanized area.
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After splitting all qualifying urbanized agglomerations into their
component urbanized areas, the Census Bureau will examine all urban
area cores sharing territory contained within the boundaries of the
same urban area previously defined for the Census 2000. The Census
Bureau will merge qualifying urban territory if an urban area defined
for the Census 2000 is at risk of changing urban status from an
urbanized area to an urban cluster, or losing its urban status
entirely. If it is possible to maintain the urban status of a Census
2000 urban area, the Census Bureau will merge noncontiguous urban
territories in descending order of population \14\ until the urban area
status threshold is met.\15\
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\14\ All urban territory separated solely by water may also be
merged regardless of its population.
\15\ Nonqualifying intervening territory separating the merged
urban territories will be included to avoid the formation of
noncontiguous urban areas.
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After application in their entirety, the splitting and merging
criteria will not prevent the formation of new urban areas consisting
of territory previously defined as belonging to a Census 2000 urban
area. These criteria also will not completely prevent urban areas from
changing urban status.
6. Inclusion of Indentations
The Census Bureau will evaluate and include territory that forms an
indentation within an urban area. This recognizes that small, sparsely
settled areas that are partially enveloped by urban territory are more
likely to be affected by and integrated with contiguous urban
territory.
To determine whether an indentation should be included in the urban
area, the Census Bureau will identify a closure line, defined as a
straight line no more than one mile in length, that extends from one
point along the edge of the urban area across the mouth of the
indentation to another point along the edge of the urban area.
A census block located wholly or partially within an indentation
will be included in the urban area, if at least 75 percent of the area
of the block is inside the closure line. The total area of those blocks
that meet or exceed the 75 percent criterion is compared to the area of
a circle, the diameter of which is the length of the closure
qualification line. The territory within the indentation will be
included in the urban area if its area is at least four times the area
of the circle and less than 3.5 square miles.
If the collective area of the census blocks inside the closure line
does not meet the criteria listed above, the Census Bureau will define
successive closure lines within the indentation, starting at its mouth
and working inward toward the base of the indentation, until the
criteria for inclusion are met or it is determined that the indentation
will not qualify for inclusion.
7. Inclusion of Airports
After all territory has been added to the urban area via hop and
jump connections, enclaves, and indentations,
[[Page 53042]]
the Census Bureau will then add whole census blocks that approximate
the territory of major airports, provided at least one of the blocks
that represent the airport is within a distance of 0.5 miles of the
edge of qualifying urban territory. An airport qualifies for inclusion,
if it is currently functional and had an annual enplanement of at least
2,500 passengers in any year between 2001 and the last year of
reference in the FAA Air Carrier Activity Information System.\16\ In
cases where the qualifying airport is not contiguous to the qualifying
urban area, the intervening nonqualifying census blocks will also be
included in the urban area.
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\16\ The annual passenger boarding data only includes primary
and nonprimary commercial service enplanements as defined and
reported by the FAA Air Carrier Activity Information System.
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8. Additional Nonresidential Urban Territory
The Census Bureau will identify additional nonresidential urban-
related territory that is noncontiguous, yet near the urban area. The
Census Bureau recognizes the existence of large commercial and/or
industrial land uses that are separated from an urban area by a
relatively thin ``green buffer,'' small amount of undeveloped
territory, and/or narrow census block required for tabulation (such as
a water feature, offset boundary, road median, or area between a road
and rail feature). The Census Bureau will review all groups of census
blocks whose members qualify as urban via the impervious surface
criteria set forth in Section 1.b, have a total area of at least 0.15
square miles,\17\ and are within 0.25 miles of an urban area. A final
review of these census blocks and surrounding territory\18\ will
determine whether to include this territory in an urban area.
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\17\ The Census Bureau found in testing that individual (or
groups of) census blocks with a high degree of impervious surface
land cover with an area less than 0.15 square miles tend to be more
associated with road infrastructure features such as cloverleaf
overpasses and multilane highway medians.
\18\ Additional census blocks within eighty feet of the initial
groups also qualifying as impervious, but failing the shape index,
are also identified for review.
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9. Assigning Urban Area Titles
A clear, unambiguous title based on commonly recognized place names
helps provide context for data users, and ensures that the general
location and setting of the urban area can be clearly identified and
understood. The title of an urban area identifies the place(s) that is
(are) most populated within the urban area. All population requirements
for places and minor civil divisions (MCDs) apply to the portion of the
entity's population that is within the specific urban area being named.
The following criteria will be used by the Census Bureau to determine
the title of an urban area:
a. The most populous incorporated place with a population of 10,000
or more within the urban area will be listed first in the urban area
title.
b. If there is no incorporated place with a population of 10,000 or
more, the urban area title will include the name of the most populous
incorporated place or CDP having at least 2,500 people in the urban
area.
Up to two additional places, in descending order of population
size, may be included in the title of an urban area provided that:
c. The place has 250,000 or more people in the urban area, or
d. The place has at least 2,500 people in the urban area, and that
population is at least two-thirds of the urban area population of the
most populous place in the urban area.
If the urban area does not contain a place with an urban population
of at least 2,500 people, the Census Bureau will consider the name of
the incorporated place, CDP, or MCD with the largest total population
in the urban area, or a local name recognized for the area by the
United States Geological Survey's (USGS) Geographic Names Information
System (GNIS), with preference given to names also recognized by the
United States Postal Service (USPS). The urban area title will include
the USPS abbreviation of the name of each state or statistically
equivalent entity into which the urban area extends. The order of the
state abbreviations is the same as the order of the related place names
in the urban area title.\19\ If an MCD name is used (outside of New
England), the title also will include the name of the county in which
the MCD is located.
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\19\ In situations where an urban area is only associated with
one place name but is located in more than one state, the order of
the state abbreviations will begin with the state within which the
place is located and continue in descending order of population of
each state's share of the population of the urban area.
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If a single place or MCD qualifies as the title of more than one
urban area, the largest urban area will use the name of the place or
MCD. The smaller urban area will have a title consisting of the place
or MCD name and the direction (North, South, East, and/or West) of the
smaller urban area as it relates geographically to the larger urban
area with the same place or MCD name.
If any title of an urban area duplicates the title of another urban
area within the same state, or uses the name of an incorporated place
or CDP, that is duplicated within a state, the name of the county that
has most of the population of the largest place or MCD is appended, in
parentheses, after the duplicate place name for each urban area. If
there is no incorporated place or CDP name in the urban area title, the
name of the county having the largest total population residing in the
urban area will be appended to the title.
C. Definitions of Key Terms
Census Block: A geographic area bounded by visible and/or invisible
features shown on a map prepared by the Census Bureau. A block is the
smallest geographic entity for which the Census Bureau tabulates
decennial census count data.
Census Designated Place (CDP): A statistical geographic entity
encompassing a concentration of population, housing, and commercial
structures that is clearly identifiable by a single name, but is not
within an incorporated place. The CDPs are the statistical counterparts
of incorporated places and represent distinct, unincorporated
communities.
Census Tract: A small, relatively permanent statistical geographic
division of a county defined for the tabulation and publication of
Census Bureau data. The primary goal of the census tract program is to
provide a set of nationally consistent, small, statistical geographic
units, with stable boundaries that facilitate analysis of data between
decennial censuses.
Contiguous: A geographic term referring to two or more areas that
are adjacent to one another, sharing either a common boundary or at
least one common point.
Core Based Statistical Area (CBSA): A statistical geographic entity
defined by the U.S. Office of Management and Budget (OMB), consisting
of the county or counties associated with at least one core (urban
area) of at least 10,000 population, plus adjacent counties having a
high degree of social and economic integration with the core as
measured through commuting ties with the counties containing the core.
Metropolitan and micropolitan statistical areas are the two types of
CBSAs.
Enclave: A territory not qualifying as urban that is either
completely surrounded by qualifying urban territory or surrounded by
qualifying urban territory and water.
Exempted Territory: A territory that is exempt from the urban area
criteria because its extent is entirely of water or an unpopulated road
corridor that crosses water.
[[Page 53043]]
Group Quarters (GQ): A place where people live or stay, in a group
living arrangement that is owned or managed by an entity or
organization providing housing and/or services for the residents. These
services may include custodial or medical care, as well as other types
of assistance, and residency is commonly restricted to those receiving
these services.
Hop: A connection from one urban area core to other qualifying
urban territory along a road connection of 0.5 miles or less in length.
Impervious Surface: Man-made surfaces, such as building roofs,
roads, and parking lots.
Incorporated Place: A type of governmental unit, incorporated under
state law as a city, town (except in New England, New York, and
Wisconsin), borough (except in Alaska and New York), village, or other
legally recognized description that provides a wide range governmental
services for a concentration of people within legally prescribed
boundaries.
Indentation: A recess in the boundary of an urban area produced by
settlement patterns and/or water features resulting in a highly
irregular urban area shape.
Initial Urban Area Core: Contiguous territory qualifying as urban
according to population count, density, and degree of impervious
surface land cover.
Institutional Group Quarters: People under formally authorized,
supervised care or custody in institutions at the time of enumeration,
who are generally, restricted to the institution, under the care or
supervision of trained staff, and classified as ``patients'' or
``inmates.''
Jump: A connection from one urban area core to other qualifying
urban territory along a road connection that is greater than 0.5 miles,
but less than or equal to 2.5 miles in length.
MAF/TIGER (MTDB): Database developed by the Census Bureau to
support its geocoding, mapping, and other product needs for the
decennial census and other Census Bureau programs. The Master Address
File (MAF) is an accurate and current inventory of all known living
quarters including address and geographic location information. The
Topologically Integrated Geographic Encoding and Referencing (TIGER)
database defines the location and relationship of boundaries, streets,
rivers, railroads, and other features to each other and to the numerous
geographic areas for which the Census Bureau tabulates data from its
censuses and surveys.
Metropolitan Statistical Area: A core based statistical area (CBSA)
associated with at least one urbanized area that has a population of at
least 50,000. A metropolitan statistical area comprises a central
county or counties containing the urbanized area, plus adjacent
outlying counties having a high degree of social and economic
integration with the central county as measured by commuting.
Micropolitan Statistical Area: A core based statistical area (CBSA)
associated with at least one urban cluster that has a population of at
least 10,000, but less than 50,000. A micropolitan statistical area
comprises a central county or counties containing the urban cluster,
plus adjacent outlying counties having a high degree of social and
economic integration with the central county as measured by commuting.
Minor Civil Division (MCD): The primary governmental or
administrative division of a county in 29 states and the Island Areas
having legal boundaries, names, and descriptions. MCDs represent many
different types of legal entities with a wide variety of
characteristics, powers, and functions depending on the state and type
of MCD. In some states, some or all of the incorporated places also
constitute MCDs.
New England City and Town Area (NECTA): A statistical geographic
entity that is delineated by the U.S. Office of Management and Budget
(OMB) using cities and towns in the New England states as building
blocks rather than counties, and that is conceptually similar to the
metropolitan and micropolitan statistical areas.
Noncontiguous: A geographic term referring to two or more areas
that do not share a common boundary or a common point along their
boundaries, such that the areas are separated by intervening territory.
Noninstitutional Group Quarters: Dwelling of people who live in
group quarters other than institutions.
Rural: Territory not defined as urban.
Urban: Generally, densely developed territory, encompassing
residential, commercial, and other nonresidential urban land uses
within which social and economic interactions occur.
Urban Area: The generic term used to refer collectively to
urbanized areas and urban clusters.
Urban Cluster (UC): A statistical geographic entity consisting of a
densely settled core created from census tracts or blocks and
contiguous qualifying territory that together have at least 2,500
persons but fewer than 50,000 persons.
Urbanized Area (UA): A statistical geographic entity consisting of
a densely settled core created from census tracts or blocks and
contiguous qualifying territory that together have a minimum population
of at least 50,000 persons.
Executive Order 12866
This notice has been determined to be not significant under
Executive Order 12866.
Paperwork Reduction Act
This notice does not contain a collection of information subject to
the requirements of the Paperwork Reduction Act, 44 United States Code,
chapter 35.
Dated:August 16, 2011.
Robert M. Groves,
Director, Bureau of the Census.
[FR Doc. 2011-21647 Filed 8-23-11; 8:45 am]
BILLING CODE 3510-07-P