Census Tract Program for the 2010 Decennial Census; Final Criteria
Federal Register: March 14, 2008 (Volume 73, Number 51)
Notices
Page 13836-13844
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
DOCID:fr14mr08-33
DEPARTMENT OF COMMERCE
Bureau of the Census
Docket Number 070321065-7903-02
Census Tract Program for the 2010 Decennial Census--Final
Criteria
AGENCY: Bureau of the Census, Commerce.
ACTION: Notice of Final Criteria and Program Implementation.
SUMMARY: Census tracts are relatively permanent small-area geographic divisions of a county or statistically equivalent entity \1\ defined for the tabulation and presentation of data from the decennial census and selected other statistical programs. Census tracts will also be used to tabulate and publish estimates from the American Community
Survey (ACS) \2\ after 2010. 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 across time.
\1\ For the Census Bureau's purposes, the term ``county'' includes parishes in Louisiana; boroughs, city and boroughs, municipalities, and census areas in Alaska; independent cities in
Maryland, Missouri, Nevada, and Virginia; districts and islands in
American Samoa; districts in the U.S. Virgin Islands; municipalities in the Commonwealth of the Northern Mariana Islands; municipios in
Puerto Rico; the areas constituting the District of Columbia and
Guam. This notice will refer to all these entities collectively as
``counties.''
\2\ The ACS is conducted in the United States and in Puerto
Rico. In Puerto Rico the survey is called the Puerto Rico Community
Survey (PRCS). For ease of discussion, throughout this document the term ACS is used to represent the surveys conducted in the United
States and in Puerto Rico.
This Notice announces the Bureau of the Census' (Census Bureau's) final criteria for the Census Tract Program for the 2010 Decennial
Census. In addition, this Notice contains a summary of comments received to proposed criteria published in the April 6, 2007, Federal
Register (72 FR 17329), as well as the Census Bureau's response to those comments. In response to comments received, the Census Bureau has modified its proposed criteria for the Census Tract Program for the 2010 Decennial Census.
Upon publication of the final census tract criteria contained in this Notice, the Census Bureau will offer governments, organizations, and interested data users the opportunity to review and, if necessary, suggest updates to the boundaries and attributes (e.g., tract code) of the census tracts in their geographic area as part of the Participant
Statistical Areas Program (PSAP). In addition, to census tracts, the
PSAP also encompasses the review and update of block groups, census designated places, and census county divisions (in selected states).
DATES: This notice's final criteria will be effective on March 14, 2008.
FOR FURTHER INFORMATION CONTACT: The Geographic Standards and Criteria
Branch, Geography Division, U.S. Census Bureau, via e-mail at geo.psap.list@census.gov or telephone at (301) 763-3056.
SUPPLEMENTARY INFORMATION:
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History of Census Tracts
In 1905, Dr. Walter Laidlaw originated the concept of permanent, small geographic areas as a framework for studying change from one decennial census to another in neighborhoods within New York City. For the 1910 Census, eight cities--New York, Baltimore, Boston, Chicago,
Cleveland, Philadelphia, Pittsburgh, and St. Louis--delineated census tracts (then termed ``districts'') for the first time. No additional jurisdictions delineated census tracts until just prior to the 1930
Census, when an additional ten cities chose to do so. The increased interest in census tracts for the 1930 Census is attributed to the promotional efforts of Howard Whipple Green, who was a statistician in
Cleveland, Ohio, and later the chairman of the American Statistical
Association's Committee on Census Enumeration Areas. For more than twenty-five years, Mr. Green strongly encouraged local citizens, via committees, to establish census tracts and other census statistical geographic areas. The committees created by local citizens were known as Census Tract Committees, later called Census Statistical Areas
Committees.
After 1930, the Census Bureau saw the need to standardize the delineation, review, and updating of census tracts and published the first set of census tract criteria in 1934. The goal of the criteria has remained unchanged; that is, to assure comparability and data reliability through the standardization of the population thresholds for census tracts, as well as requiring that their boundaries follow specific types of geographic features that do not change frequently.
The Census Bureau began publishing census tract data as part of its standard tabulations beginning with the 1940 Census. Prior to that time, census tract data were published as special tabulations.
For the 1940 Census, the Census Bureau began publishing census block data for all cities with 50,000 or more people. Census block numbers were assigned, where possible, by census tract, but for those cities that had not yet delineated census tracts, ``block areas''
(called ``block numbering areas'' [BNAs] in later censuses) were created to assign census block numbers.
Starting with the 1960 Census, the Census Bureau assumed a greater role in promoting and coordinating the delineation, review, and update of census tracts. For the 1980 Census, criteria for BNAs were changed to make them more comparable in size and shape to census tracts. For the 1990 Census, all counties contained either census tracts or BNAs.
Census 2000 was the first decade in which census tracts were defined in all counties. In addition, the Census Bureau increased the number of geographic areas whose boundaries could be used as census tract boundaries. It also allowed tribal governments of federally recognized American Indian tribes with a reservation and/or off- reservation trust lands to delineate tracts without regard to State and/or county boundaries, provided the tribe had a 1990 Census population of at least 1,000.
-
Summary of Comments Received in Response to the Proposed Criteria for the Census Tract Program for the 2010 Decennial Census
The April 6, 2007, Federal Register (72 FR 17329) requested comment on the proposed census tract criteria for the 2010 Decennial Census which contained the following changes to the criteria used in the 2000
Decennial Census: (1)
Page 13837
Lowering the minimum population threshold for most census tracts from 1,500 to 1,200; (2) using housing unit counts (as an alternative to population counts) in the review and update of tracts; (3) applying the same population and housing unit thresholds to all types of populated tracts within the United States,\3\ including census tracts delineated on American Indian reservations and off-reservation trust lands,\4\
Puerto Rico, the Island Areas,\5\ and encompassing group quarters, military installations, and institutions. For census tracts delineated in these areas, the 1,200 person threshold represents an increase from the Census 2000 threshold of 1,000 people. The minimum housing unit threshold for all census tracts would be 480. The maximum population threshold of 8,000 persons/3,200 housing units and the optimum of 4,000 persons/1,600 housing units also will apply to all types of populated census tracts; (4) allowing the delineation of census tracts for large water bodies with areas of approximately 100 square miles or more and special land use (e.g., large airports or public parks) with an official name; and (5) allowing for geographic frameworks of tribal tracts (separate from the standard census tracts defined within counties) to be defined within federally recognized American Indian reservations and off-reservation trust lands.
\3\ For Census Bureau purposes, the United States includes the fifty States and the District of Columbia.
\4\ The proposed criteria for the tribal statistical areas program will be outlined in a separate Federal Register notice. In the tribal statistical areas program, federally recognized American
Indian tribes that have a reservation and/or off-reservation trust land may delineate census designated places (CDPs), and, if these areas have a population of 2,400 or greater, may delineate tribal tracts and tribal block groups for their reservation and off- reservation trust land.
\5\ For Census Bureau purposes, the Island Areas includes
American Samoa, the Commonwealth of the Northern Mariana Islands,
Guam, the U.S. Virgin Islands, and the U.S. Minor Outlying Islands.
The U.S. Minor Outlying Islands is an aggregation of nine U.S. territories: Baker Island, Howland Island, Jarvis Island, Johnston
Atoll, Kingman Reef, Midway Islands, Navassa Island, Palmyra Atoll, and Wake Island.
The Census Bureau received comments from 11 individuals regarding the proposed use of housing unit counts in the review and update of census tracts, the permitted delineation of census tracts for large water bodies and special land uses, and the proposed tribal tract approach. Commenters represented a variety of agencies and organizations, including state and local government agencies, non- profit policy research and analysis organizations, non-governmental organizations, professional societies, and private sector companies.
Comments received by the Census Bureau are summarized below, as well as the Census Bureau's response to these comments. 1. Using Housing Unit Counts in the Review and Update of Tracts
The Census Bureau received five comments in response to the proposed use of housing unit counts in the review and update of tracts and block groups as an alternative to population counts where appropriate. All five comments supported the concept, although one commenter requested more guidance on when housing units should be used to define tracts instead of population. Given the support of using housing unit counts in the review and update for census tracts, the
Census Bureau will retain the concept in the final criteria for the 2010 Census. Guidance as to when housing unit counts should be used in place of population counts in the review and update of census tracts will be discussed in this notice, and further detailed in the PSAP guidelines. 2. Permitting the Delineation of Census Tracts for Large Water Bodies and Special Land Uses
The Census Bureau received four comments in response to the proposal to encourage delineation of special land use tracts. Three commenters supported the concept. One commenter neither supported nor opposed the concept, but stated that more discussion about the concept is required. Given the support of the special land use tract designation, the Census Bureau will retain the concept in the final criteria for the 2010 Decennial Census.
Three comments were received in response to the proposal to encourage delineation of large water body tracts. Two commenters supported the concept. One commenter opposed the concept, citing increased confusion and disorientation for data users with respect to what is commonly seen on non-census maps. Additional internal review and discussion of the large water body tract proposal led to a recommendation to not retain this requirement in the final criteria.
Given the mixed response to the large water tract proposal, and subsequent internal review and discussion, the Census Bureau will not retain the large water tract concept in the final criteria for the 2010
Decennial Census. 3. Allowing for a Geographic Framework of Tribal Census Tracts Defined
Within Federally Recognized American Indian Reservations and Off-
Reservation Trust Lands, and Separate From the Standard Census Tracts
Defined Within Counties
The Census Bureau received two comments supporting the proposed tribal tract approach. In addition, two commenters requested clarification of the concept. The tribal tract approach will be fully explained in the ``American Indian Areas (AIAs) for the 2010 Census--
Proposed Criteria and Guidelines'' Federal Register notice to be published.
Changes to Proposed Criteria for the Census Tract Program for the 2010
Decennial Census
Changes made to the final criteria (from the proposed criteria) in
``Section III, General Principles and Criteria for Census Tracts for the 2010 Census'' are as follows: 1. Section A, ``General Principles,'' subsection 2, fourth sentence: replaced ``local governments and planners'' with ``PSAP participants'' because not all participants in the 2010 PSAP will be representatives of local governments or will be professional planners.
In the fifth sentence, we deleted the reference to water body tracts since this proposed criterion has not been adopted in the final criteria. We also changed the wording in the fifth sentence to improve the flow of the text and provide greater clarity. 2. Section A, ``General Principles,'' subsection 2: added sentences referencing optimal population and housing unit thresholds for census tracts and the importance of the optimum threshold with regard to reliability and availability of sample-based data. 3. Section A, ``General Principles,'' subsection 3: added text to help clarify why we are now permitting the use of housing unit counts in the review and updating of census tracts for the 2010 Census. 4. Section A, ``General Principles,'' subsection 4: removed the reference to water body tracts since this proposed criterion has not been adopted in the final criteria. 5. Section B, ``Changes to the Census Tract Criteria for the 2010
Census:'' this section was omitted from this Notice as all changes are addressed in the final criteria. 6. Section C, ``Census Tract Criteria for the 2010 Census:'' moved the following criterion ``Census tracts must not cross State and county boundaries,'' as the first listed criterion. Because this criterion supersedes all other criteria, we felt it required specific mention.
Page 13838
7. Section C in the April 6, 2007 Federal Register (72 FR 17329) is now Section B. 8. Section C, ``Census Tract Criteria for the 2010 Census:'' the criterion listed first, ``A census tract must comprise a reasonably compact and contiguous land area,'' is now listed third in this notice, partly as a result of the addition of the criterion relating to adherence to state and county boundaries, but also to produce a more logical flow to the criteria. As a result of this change, and the change listed above, all other criteria in this section have been renumbered. 9. Section C, ``Census Tract Criteria for the 2010 Census,'' subsection 4.g: removed reference to water body tracts since that proposed criterion has been eliminated from the final criteria. 10. Section C, ``Census Tract Criteria for the 2010 Census,'' subsection 5: added the word ``measurement'' after ``area'' in the title of the subsection, in the text, and in the table providing tract thresholds. In subsection 5a, we revised the wording to improve flow and provide greater clarity. 11. Section C, ``Census Tract Criteria for the 2010 Census,'' subsection 5c: we revised the text in this subsection to provide greater clarity. We removed the reference to the level of population or housing units at which a tract need not be merged since this is not a specific criterion. The Census Bureau will provide a variety of examples in the PSAP guidelines to help guide participants when deciding whether to merge adjacent tracts. 12. Section C, ``Census Tract Criteria for the 2010 Census,'' subsections 5d and 5e: we changed the order in which these subsections appear in the final criteria to provide a more logical flow to the presentation. In addition, we deleted the reference to water body tracts that appeared in subsection 5e of the proposed criteria. 13. Section C, ``Census Tract Criteria for the 2010 Census,'' subsection 6b: removed criteria pertaining to codes for water body tracts since water body tracts have been deleted from the final criteria, and modified the high end of the range of allowable census tract identifiers from 9949 to 9989. 14. Section C, ``Census Tract Criteria for the 2010 Census,'' subsection 7: added the word ``measurement'' after ``area'' in the text and table in this section. 15. Section D, ``Tribal Tracts:'' in response to comments received, we revised wording throughout the section to provide greater clarity.
Discussion of tribal tracts is contained in Section C of this Notice.
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General Principles and Criteria for Census Tracts for the 2010
Decennial Census
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General Principles 1. A century of census tract use has shown that continuity and comparability in tracts and their boundaries over time are of considerable importance to data users. Comparability has always been a goal in the census tract program since its inception for the 1910 census; however, as the use of tract data increases, the importance of comparability increases as well. Maintaining comparability of tract boundaries over time facilitates longitudinal data analysis. The advent of the ACS and the averaging of sample data for tracts over a five-year span further underscore the need for consistent tract boundaries over time.
Pursuant to this goal of continuity and comparability, the Census
Bureau requests that where a census tract must be updated, for example to meet the minimum or maximum population or housing unit thresholds, that the outer boundaries of the tract not be changed, but rather that a tract be split into two or more tracts, or merged with an adjacent tract. The Census Bureau discourages changes to tract boundaries (that is, ``retracting''), except in specified circumstances, which the
Census Bureau will review on a case-by-case basis. 2. The sample size for the ACS is smaller than the sample from the decennial census long form of previous censuses. As a general rule, estimates from programs providing sample data, including the ACS, for geographic areas with smaller populations will be subject to higher variances than comparable estimates for areas with larger populations.
In addition, the Census Bureau's disclosure rules may have the effect of restricting the availability and amount of sample data published for geographic areas with small populations. Aiming to create census tracts that meet the optimal population of 4,000 and maintaining minimum thresholds will improve the reliability and availability of data, and
PSAP participants should consider these factors when defining their census tracts. Therefore, each census tract must encompass at least 1,200 people or at least 480 housing units unless it is flagged as a special land use tract, or is coextensive with a county with fewer than 1,200 people. Any census tract with a population or housing unit count less than the minimum threshold should be merged with an adjacent census tract to form a single tract with at least 1,200 people or at least 480 housing units (Figure 1). Optimally, census tracts should have 4,000 people or 1,600 housing units. Meeting or exceeding the optimum thresholds will help improve the reliability of sample data for census tracts. The Census Bureau will use Census 2000 population and housing unit counts, with allowance made for growth since 2000, to assess whether each census tract submitted meets this criterion.
Program participants may submit local estimates as a surrogate for the
Census 2000 population and housing unit counts for a census tract.
Page 13839
GRAPHIC
TIFF OMITTED TN14MR08.074 3. With the advent of the ACS and the ``continuous measurement'' of characteristics of the population and housing based on a five-year average, there are some new issues to consider in the census tract criteria. To accommodate this change, either population or housing units may be used in the review of census tracts. The use of housing unit counts accommodates seasonal communities in which residents often are not present on the date of the decennial census, but will be present at other times of the year and for which period estimates may be reflected in the ACS. The ACS is designed to produce local area data as of a 12-month period estimate (or an average); whereas, in the past local area data were represented as of the April 1 census day. 4. The Census Bureau recognizes that there are geographic areas that are not characterized by a residential population, and which local participants may wish to separate from populated tracts for analytical or cartographic purposes or both. Such areas may be designated as special land use tracts to distinguish them from populated census tracts. Special land use tracts must be designated as a specific type of land use (e.g., state park, municipal park) and have an official name, generally have little or no residential population or housing units, and must not create a noncontiguous census tract. If located in a densely populated urban area, a special land use tract must have an area measurement of approximately 1 square mile or more. If delineated completely outside an urban area, a special land use tract must have an area of approximately 10 square miles or more. The Census Bureau recognizes that some special land use areas not intended for residential population, such as parks, may contain some population, such as caretakers or the homeless. Our intent is to allow for the delineation of parks and other special land use areas as separate tracts and therefore will accept such areas as tracts even if some residential population is present. 5. To facilitate the analysis of data for American Indian tribes, and to recognize their unique governmental status, program participants are encouraged to merge, split, or redefine census tracts to avoid unnecessarily splitting American Indian reservations and off- reservation trust lands. Each contiguous American Indian reservation and/or off-reservation trust land should be included, along with any necessary territory outside the reservation and/or off-reservation trust land, within a single census tract or as few census tracts as possible for the 2010 Census. This is the only situation in which retracting is encouraged. For example, see Figure 2 below.
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GRAPHIC
TIFF OMITTED TN14MR08.075
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Census Tract Criteria for the 2010 Decennial Census
The criteria herein apply to the United States, including federally recognized American Indian reservations and off-reservation trust lands, Puerto Rico, and the Island Areas. The Census Bureau may modify and, if necessary, reject any proposals for census tracts that do not meet these final criteria. In addition, the Census Bureau reserves the right to modify the boundaries and attributes of tracts as needed to meet the published criteria and/or maintain geographic relationships before the final tabulation geography is set for the 2010 Census.
The Census Bureau Sets Forth the Following Criteria for Use in
Reviewing, Updating, and Delineating 2010 Census Tracts: 1. Census tracts must not cross state or county boundaries. 2. A census tract must cover the entire land and water area of a county. 3. A census tract must comprise a reasonably compact and contiguous land area.
Noncontiguous boundaries are permitted only where a noncontiguous area or inaccessible area would not meet population or housing unit count requirements for a separate census tract, in which case the noncontiguous or inaccessible area must be included within an adjacent or proximate tract. For example, an island that does not meet the minimum population threshold for recognition as a separate tract should be combined with other proximate land to form a single tract. Each case will be reviewed and accepted at the Census Bureau's discretion. 4. Census tract boundaries should follow visible and identifiable features.
To make the location of census tract boundaries less ambiguous, wherever possible, tract boundaries should follow visible and identifiable features. The use of visible features also makes it easier to locate and identify tract boundaries over time, as the locations of many visible features in the landscape tend to change infrequently.
State and county boundaries must be census tract boundaries. The Census
Bureau also permits the use of incorporated place and minor civil division boundaries in states where those boundaries tend to remain unchanged over time (see Table 1).
The Following Features are Preferred as Census Tract Boundaries for the 2010 Census: a. State and county boundaries must always be census tract boundaries. This criterion takes precedence over all other criteria or requirements (except for tribal tracts on federally recognized American
Indian reservations and/or off-reservation trust lands). b. American Indian reservation and off-reservation trust land boundaries. c. Visible, perennial natural and cultural features, such as roads, shorelines, rivers, perennial streams and canals, railroad tracks, or above-ground high-tension power lines. d. Boundaries of legal and administrative entities in selected states.
Table 1 identifies by state which minor civil division (MCD) and incorporated place boundaries may be used as census tract boundaries.
Table 1.--Acceptable MCD and Incorporated Place Boundaries
Boundaries of MCDs not coincident with the
All MCD
boundaries of
All incorporated
Only conjoint boundaries
incorporated
place boundaries
incorporated places that
places boundaries themselves are
MCDs
Alabama......................... .................. .................. ..................
X
Alaska.......................... .................. .................. ..................
X
Arizona......................... .................. .................. ..................
X
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Arkansas........................ .................. .................. ..................
X
California...................... .................. .................. ..................
X
Colorado........................ .................. .................. ..................
X
Connecticut.....................
X ..................
X ..................
Delaware........................ .................. .................. ..................
X
Florida......................... .................. .................. ..................
X
Georgia......................... .................. .................. ..................
X
Hawaii.......................... .................. .................. ..................
X
Idaho........................... .................. .................. ..................
X
Illinois........................ ..................
X \a\ ..................
X
Indiana.........................
X .................. ..................
X
Iowa............................ ..................
X ..................
X
Kansas.......................... ..................
X ..................
X
Kentucky........................ .................. .................. ..................
X
Louisiana....................... .................. .................. ..................
X
Maine...........................
X ..................
X ..................
Maryland........................ .................. .................. ..................
X
Massachusetts...................
X ..................
X ..................
Michigan........................ ..................
X ..................
X
Minnesota....................... ..................
X ..................
X
Mississippi..................... .................. .................. ..................
X
Missouri........................ ..................
X \b\ ..................
X
Montana......................... .................. .................. ..................
X
Nebraska........................ ..................
X \a\ ..................
X
Nevada.......................... .................. .................. ..................
X
New Hampshire...................
X ..................
X ..................
New Jersey......................
X ..................
X ..................
New Mexico...................... .................. .................. ..................
X
New York........................
X ..................
X ..................
North Carolina.................. .................. .................. ..................
X
North Dakota.................... ..................
X ..................
X
Ohio............................ ..................
X ..................
X
Oklahoma........................ .................. .................. ..................
X
Oregon.......................... .................. .................. ..................
X
Pennsylvania....................
X ..................
X ..................
Rhode Island....................
X ..................
X ..................
South Carolina.................. .................. .................. ..................
X
South Dakota.................... ..................
X ..................
X
Tennessee....................... .................. .................. ..................
X
Texas........................... .................. .................. ..................
X
Utah............................ .................. .................. ..................
X
Vermont.........................
X ..................
X ..................
Virginia........................ .................. .................. ..................
X
Washington...................... .................. .................. ..................
X
West Virginia................... .................. .................. ..................
X
Wisconsin....................... ..................
X ..................
X
Wyoming......................... .................. .................. ..................
X
\a\ Townships only.
\b\ Governmental townships only. e. Additionally, the following legally defined, administrative boundaries would be permitted as census tract boundaries: i. Barrio, barrio-pueblo, and subbarrio boundaries in Puerto Rico; ii. Census subdistrict boundaries in the U.S. Virgin Islands; iii. County and island boundaries (both MCD equivalents) in
American Samoa; iv. Election district boundaries in Guam; v. Municipal district boundaries in the Commonwealth of the
Northern Mariana Islands; and vi. Alaska Native regional corporation boundaries in Alaska, at the discretion of the Census Bureau, insofar as such boundaries are unambiguous for allocating living quarters as part of 2010 Census activities. f. When acceptable visible and governmental boundary features are not available for use as tract boundaries, the Census Bureau may, at its discretion, approve other nonstandard visible features, such as ridgelines, above-ground pipelines, intermittent streams, or fence lines. The Census Bureau may also accept, on a case-by-case basis, the boundaries of selected nonstandard and potentially nonvisible features, such as the boundaries of military installations, national parks, national monuments, national forests, other types of parks or forests, airports, marine ports, cemeteries, golf courses, penitentiaries/ prisons, or glaciers, or the straight-line
Page 13842
extensions of visible features and other lines-of-sight. g. The boundaries of parks, forests, large airports, and military installations, provided the boundaries are clearly marked or easily recognized. 5. Population, Housing Unit, and Area Measurement thresholds.
The following are the population, housing unit, and area measurement threshold criteria for census tracts (as summarized in
Table 2).
Table 2.--Tract Thresholds
Tract type
Threshold type
Optimum
Minimum
Maximum
Standard & tribal tracts............. Population threshold....
4,000
1,200
8,000
Housing Unit threshold..
1,600
480
3,200
Special land use tracts.............. Area measurement
none
1.0
none threshold for an urban area (square miles).
Area measurement
none
10
none threshold outside an urban area (square miles).
Population threshold....
Little or none, or within the standard tract thresholds
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Population counts should be used, in most cases, to review and update census tracts. Housing unit counts should be used for seasonal communities that have no or low population on census day (April 1).
Locally produced population and housing unit estimates can be used when reviewing and updating tracts, especially in areas that have experienced considerable growth since Census 2000. b. The housing unit thresholds are based on a national average of 2.5 persons per household. The Census Bureau recognizes that there are regional variations to this average and will take this into consideration when reviewing all tract proposals. c. The Census Bureau recognizes the tension that exists between meeting the optimum population or housing unit threshold in a tract and maintaining tract comparability over time. For example, if sufficient population or housing unit growth has occurred since 2000 or is expected before 2010 for a census tract, based on Census 2000 data, was below the minimum thresholds, the tract should not be merged with another tract. Supporting evidence may be requested by the Census
Bureau. However, should the census tract's population not increase as expected and does not meet either of the minimum thresholds in 2010, this may adversely affect the reliability and availability of any sample estimates for that tract. For this reason, the Census Bureau suggests merging the census tract with another if there is a possibility that anticipated growth will not be sufficient to meet minimum thresholds. d. For the 2010 Census, the Census Bureau allows the delineation of special land use tracts. A special land use tract must be designated as a specific land use type (e.g., State park), must have an official name
(e.g., Jay Cooke State Park), have little or no residential population, and must not create a noncontiguous tract. In some instances, multiple areas can be combined to form a single special land use tract if the land management characteristics are similar, such as a special land use tract comprising adjacent Federal and State parks. If the special land use tract is delineated in a densely populated, urban area, the tract must have an area of approximately one square mile or more. If the special land use tract is delineated completely outside an urban area, the tract must have an area of approximately 10 square miles or more. e. The Census Bureau may waive the maximum population and housing unit thresholds as required to achieve the objectives of this notice. 6. Identification of Census Tracts. a. A census tract has a basic census tract identifier composed of no more than four digits and may have a two-digit decimal suffix. b. The range of acceptable basic census tract identifiers for the 2010 Census is from 1 to 9989 (but, see 6.c. below); tracts delineated specifically to complete coverage of large water bodies will be numbered from 9950 to 9989 in each county. c. Census tracts delineated within or to primarily encompass
American Indian reservations and/or off-reservation trust lands can continue to be numbered from 9400 to 9499. Local participants may opt to renumber these census tracts in a numeric range consistent with the rest of the county since tribal tracts will represent a separate and distinct geographic framework. d. Census tract identifiers must be unique within each county. e. Once used, census tract identifiers cannot be reused in a subsequent census to reference a completely different area within a county. If a tract is split, each portion may keep the same basic 4- digit identifier, but each portion must be given a unique suffix. If a census tract that was suffixed for Census 2000 is split, each portion must be given a new suffix. f. The range of acceptable census tract suffixes is .01 to .98. 7. Census Tract types.
Table 3 provides a summary of the types of census tracts (with their respective population, housing unit, and area measurement thresholds) that the Census Bureau will use for the 2010 Census.
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Table 3.--Summary of Census Tract Types
How distinct from
Population
Housing unit
Area measurement standard census tracts
thresholds
thresholds
thresholds
Standard & tribal tracts....... Tribal tracts are
Optimum: 4,000;
Optimum: 1,600; none. conceptually similar
Minimum: 1,200;
Minimum: 480; and equivalent to
Maximum: 8,000.
Maximum: 3,200. census tracts defined within the standard state-county-tract- block group geographic hierarchy used for tabulating and publishing statistical data.
Special land use tract......... A tract encompassing a Little or none... Little or none... 1.0 square mile large airport, public
within an urban park, or public
area/10 square forest with little or
miles outside an no population or
urban area. housing units. In a densely populated, urban area, a special land use tract should be approximately 1 square mile in area or greater. If delineated completely outside an urban area, a special land use tract should have an area of 10 square miles or greater.
-
-
Tribal Tracts
Tribal tracts are statistical geographic entities defined by the
Census Bureau in cooperation with tribal officials to provide meaningful, relevant, and reliable data for small geographic areas within the boundaries of federally recognized American Indian reservations and/or off-reservation trust lands. As such, they recognize the unique statistical data needs of federally recognized
American Indian tribes. The delineation of tribal tracts allows for an unambiguous presentation of tract-level data specific to the American
Indian reservation and/or off-reservation trust lands without the imposition of state or county boundaries, which might artificially separate American Indian populations located within a single reservation and/or off-reservation trust land. To this end, the
American Indian tribal participant may define tribal tracts that cross county or State boundaries, or both. For federally recognized American
Indian tribes with reservations and/or off-reservation trust lands that have more than 2,400 residents, the Census Bureau will offer the tribal government the opportunity to delineate tribal tracts and other tribal statistical geography on their reservation and/or off-reservation trust land. For federally recognized tribes with an American Indian reservation and/or off-reservation trust lands that have fewer than 2,400 residents, the Census Bureau will define one tribal tract coextensive with the reservation and/or off-reservation trust land.
Tribal tracts must be delineated to meet all other census tract criteria, and must be numbered uniquely so as to clearly distinguish them from county-based census tracts. Tribal tracts are conceptually similar and equivalent to census tracts defined within the standard
State-county-tract geographic hierarchy used for tabulating and publishing statistical data.
Tribal tracts are defined to provide meaningful and reliable statistical data, particularly sample-based data, for small geographic areas within a reservation and/or off-reservation trust land. To accomplish this in as meaningful a manner as possible, tribal tract geography will constitute a geographic framework separate from standard county-based census tracts and will be defined through a separate program designed specifically for tribal statistical geography. This differs from the procedure for Census 2000 in which tribal tracts were defined for federally recognized American Indian reservations and/or off-reservation trust lands and standard census tracts were identified by superimposing county and state boundaries onto the tribal tracts.
For Census 2000 products in which data were presented by state and county, the standard state-county-census tract hierarchy was maintained, even for territory contained within an American Indian reservation and/or off-reservation trust land. In such instances, the state/county portions of a tribal tract were identified as individual census tracts. These standard census tracts may not have met the minimum population thresholds; therefore, potentially limiting sample data reliability or availability for both the tribal tract and the derived standard tracts. The change in the tribal tract program for the 2010 Census, creating standard, county-based census tracts nationwide and maintaining tribal tracts as a completely separate set of geography from standard tracts for both geographic information and data presentation purposes, seeks to eliminate, in part, these issues that existed with Census 2000 data.
As with standard census tracts submitted through this program, the tribal tracts will be submitted to the Census Bureau, and will be subject to review to ensure compliance with the final published criteria. Tribal tracts will be defined as part of a separate Tribal
Statistical Areas Program (TSAP) for the 2010 Census. Detailed criteria pertaining to tribal tracts will be published in a separate Federal
Register notice pertaining to all American Indian statistical areas defined through the TSAP.
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Definitions of Key Terms
Alaska Native regional corporation (ANRC)--A corporate geographic area established under the Alaska Native Claims Settlement Act (Pub. L. 92-203, 85 Stat. 688 (1971)) to conduct both the business and nonprofit affairs of Alaska Natives. Twelve ANRCs cover the entire state of
Alaska except for the Annette Island Reserve.
American Indian off-reservation trust land--A federally recognized
American Indian land area located outside the boundaries of an American
Indian reservation whose boundaries are established by deed and over which a federally recognized American Indian tribal government has governmental authority.
American Indian reservation (AIR)--A federally recognized American
Indian land area with boundaries established by final treaty, statute, executive order, and/or court order and over which a federally recognized American Indian tribal government has governmental authority. Along with reservation, designations such as colonies, communities, pueblos, rancherias, and reserves apply to AIRs.
Conjoint--A description of a boundary shared by two adjacent geographic entities.
Contiguous--A description of areas sharing common boundaries, such that
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the areas, when combined, form a single piece of territory.
Noncontiguous areas form disjoint pieces.
Group quarters--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. This is not a typical household-type living arrangement. 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.
People living in group quarters are usually not related to each other.
Group quarters include such places as college residence halls, residential treatment centers, skilled nursing facilities, group homes, military barracks, correctional facilities, and workers' dormitories.
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), or village, generally to provide governmental services for a concentration of people within legally prescribed boundaries.
Minor civil division (MCD)--The primary governmental or administrative division of a county in 28 states and the Island Areas having legal boundaries, names, and descriptions. The 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.
Nonvisible feature--A map feature that is not visible on the ground such as a city or county boundary through space, a property line, or line-of-sight extension of a road.
Retracting--Substantially changing the boundaries of a tract so that comparability over time is not maintained.
Special land use tract--Type of census tract that must be designated as a specific land use type (e.g., state park) and have an official name (e.g., Jay Cooke State Park), must have little or no residential population or housing units, and must not create a noncontiguous tract. If delineated in a densely populated, urban area, a special land use tract must have an area of approximately one square mile or more. If delineated completely outside an urban area, a special land use tract must have an area of approximately 10 square miles or more.
TIGER[reg]--Topologically Integrated Geographic Encoding and
Referencing database developed by the Census Bureau to support its mapping needs for the decennial census and other Census Bureau programs. The topological structure of the TIGER[reg] 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.
Visible feature--A map feature that can be seen on the ground, such as a road, railroad track, major above-ground transmission line or pipeline, river, stream, shoreline, fence, sharply defined mountain ridge, or cliff. A nonstandard visible feature is a feature that may not be clearly defined on the ground (such as a ridge), may be seasonal
(such as an intermittent stream), or may be relatively impermanent
(such as a fence). The Census Bureau generally requests verification that nonstandard features used as boundaries for the PSAP geographic areas pose no problem in their location during field work.
Executive Order 12866
This notice has been determined to be not significant under
Executive Order 12866.
Paperwork Reduction Act
This program notice does not contain a collection of information subject to the requirements of the Paperwork Reduction Act, 44 U.S.C.,
Chapter 35.
Dated: March 10, 2008.
Steve H. Murdock,
Director, Bureau of the Census.
FR Doc. E8-5076 Filed 3-13-08; 8:45 am
BILLING CODE 3510-07-P
