[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  

[[Page 53030]]


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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).

------------------------------------------------------------------------
                              Proposed 2010 Census    Final 2010 Census
          Criteria                  criteria              criteria
------------------------------------------------------------------------
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.
------------------------------------------------------------------------

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.
---------------------------------------------------------------------------

    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.
---------------------------------------------------------------------------

    \2\ The NLCD includes data for the entirety of the United 
States, Puerto Rico, and the U.S. Virgin Islands.
---------------------------------------------------------------------------

    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.
---------------------------------------------------------------------------

    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.
---------------------------------------------------------------------------

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.
---------------------------------------------------------------------------

    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