[Federal Register Volume 62, Number 19 (Wednesday, January 29, 1997)]
[Notices]
[Pages 4246-4249]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-2185]
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DEPARTMENT OF COMMERCE
Bureau of the Census
[Docket No. 961213356-6356-01]
RIN 0607-XX25
Census Tract Program for Census 2000--Proposed Criteria
AGENCY: Bureau of the Census, Commerce.
ACTION: Notice of proposed program revisions and request for comments.
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SUMMARY: Census tracts are relatively permanent small-area geographic
divisions of a county or statistically
[[Page 4247]]
equivalent entity 1 defined for the tabulation of decennial census
data and selected other statistical programs. The primary goal of the
census tract program is to provide a geographic unit that has stable
boundaries between decennial censuses. Other goals include the
identification of geographic areas that represent meaningful geographic
divisions of a county based on economic or social interaction,
significant topographic differences within a county, or a certain
degree of demographic homogeneity at the time of original delineation.
The Census Bureau uses census tracts to tabulate and disseminate a wide
variety of data. For Census 2000, census tracts will be established
across the entire area of the United States, Puerto Rico, and the
Island Areas (American Samoa, Guam, the Northern Mariana Islands, and
the Virgin Islands of the United States).
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\1\ Includes parishes in Louisiana; boroughs and census areas in
Alaska; independent cities in Maryland, Missouri, Nevada, and
Virginia; that portion of Yellowstone National Park in Montana;
districts in American Samoa and the Virgin Islands of the United
States; municipalities in the Northern Mariana Islands; municipios
in Puerto Rico; and the entire area constituting the District of
Columbia; and Guam. This notice will refer to all these entities
collectively as ``counties.''
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Census tracts first appeared in the 1910 census when local
officials in eight of the larger cities delineated these areas. In the
1910, 1920, and 1930 censuses, the Census Bureau published census tract
data as special tabulations; in 1940, the Census Bureau began including
census tract data in its standard publications. The number of data
subjects and the amount of data, as well as the number of counties
containing census tracts, increased in every census through 1990. For
the 1990 census, the Census Bureau inaugurated complete nationwide
coverage and statistics for census tracts or statistically equivalent
entities known as block numbering areas (BNAs.) For Census 2000, the
Census Bureau will combine the similar programs into a single census
tract program.
To determine the boundaries and identification numbers of census
tracts, the Census Bureau offers a program to local participants, such
as locally identified agencies and American Indian tribal officials,
whereby they can review and update the boundaries of the census tracts
and BNAs delineated for the 1990 census and suggest revisions according
to the criteria developed and promulgated by the Census Bureau. The
Census Bureau will then review the resulting Census 2000 census tract
plans for conformance to these criteria.
As the first step in this process, the Census Bureau requests
comments on its proposed criteria for the delineation of census tracts
in conjunction with Census 2000. These criteria will apply to the 50
states, the District of Columbia, American Indian and Alaska Native
areas, Puerto Rico, and the Island Areas. The Census Bureau may modify
and, if necessary, reject proposals for census tracts that do not meet
the criteria established following this notice.
Besides the proposed criteria, this notice includes a description
of the changes from the criteria used for the 1990 census and a list of
definitions of key terms used in the criteria.
DATE: Any suggestions or recommendations concerning the proposed
criteria should be submitted in writing by February 28, 1997.
ADDRESS: Director, Bureau of the Census, Washington, DC 20233-0001.
FOR FURTHER INFORMATION CONTACT: Dr. Joel Morrison, Chief, Geography
Division, Bureau of the Census, Washington, DC 20233-7400, telephone
(301) 457-1132, or e-mail to joel.morrison@census.gov.''
SUPPLEMENTARY INFORMATION: The census tract delineation criteria have
evolved over the past nine decades in response to decennial census
practices and the preferences of local participants and data users.
After each decennial census, the Census Bureau, in consultation with
past participants and data users, reviews and revises these criteria.
Then, before the next decennial census, the Census Bureau offers state,
tribal, and local officials an opportunity to correct, update, and
otherwise improve the universe of census tracts.
In July and August 1995, the Census Bureau issued invitations to
local groups and agencies to participate in the delineation of
statistical geographic areas for Census 2000. These groups and agencies
included regional planning agencies, councils of governments, county
planning agencies, officials of Federally recognized American Indian
tribes, and officials of the 12 nonprofit Alaska Native Regional
Corporations.
In 1997, the Census Bureau will provide materials and detailed
guidelines to program participants for the review and delineation of
census tracts for Census 2000.
A. Criteria for Delineating Census Tracts for Census 2000
The Census Bureau proposes the following criteria for use in
delineating Census 2000 census tracts.
1. General Characteristics
A census tract must meet the population and boundary
feature criteria and comprise a reasonably compact, continuous land
area internally accessible to all points by road; the only exceptions
are:
(a) where the tract is defined to include a specific legal or land-
use area that itself is discontinuous, in which case discontinuity is
allowed.
(b) where a discontinuous area or inaccessible area would not meet
population size requirements for a separate census tract, in which case
the discontinuous or inaccessible area must be combined within an
adjacent or proximate census tract.
(c) where the topography or geographic patterns of settlement are
not compact, but are irregularly shaped, in which case a census tract
shape can depart from the compactness requirement.
A county boundary always must be a census tract boundary.
This criterion takes precedence over all other criteria or requirements
except for the population threshold criteria for census tracts on
American Indian reservations (AIRs) in multiple counties.
Census tracts must cover the entire land and inland water
area of each county. In coastal waters, territorial seas, and the Great
Lakes, the Census Bureau recommends creating in each county a single
census tract covering such water bodies to provide for complete census
tract coverage.
2. Identification
A census tract has a basic census tract number composed of
no more than four digits and may have a two-digit decimal suffix.
Census tract numbers must be unique within each county.
The range of acceptable basic census tract numbers for
Census 2000 is 1 to 9989; census tracts delineated specifically to
complete coverage in territorial seas and the Great Lakes will use the
number 0000 in each county.
Census tracts delineated within or to encompass an AIR
that crosses county or state and county boundaries, where the intent is
for the census tract to ignore the county or state boundary for
tabulation in an American Indian geographic hierarchy, will use numbers
9400 to 9499.
The range of acceptable census tract suffixes is .01 to
.98. The Census Bureau reserves the .99 suffix to identify civilian and
military ships as ``crews-of-vessels'' census tracts.
3. Boundary Features
The Census Bureau recommends that most census tract boundaries
follow visible and identifiable features. This makes the location of
census tract boundaries less ambiguous. The Census
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Bureau also permits the use of legal boundaries in some states and
situations to allow for census tract-to-governmental unit relationships
where the governmental boundaries tend to remain unchanged between
censuses. The following features are acceptable as census tract
boundaries for Census 2000:
All state and county boundaries (always required).
Visible, perennial natural and cultural features, such as
roads, rivers, canals, railroads, above-ground high-tension power
lines, and so forth.
All minor civil division (MCD) boundaries (generally towns
or townships) in Connecticut, Indiana, Maine, Massachusetts, New
Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and
Vermont.
Those MCD boundaries not coincident with the boundaries of
incorporated places that themselves are MCDs (being either coextensive
with an MCD or independent of MCDs) in Illinois (townships only, not
election precincts), Iowa, Kansas, Michigan, Minnesota, Missouri
(governmental townships only), Nebraska (townships only, not election
precincts), North Dakota, Ohio, South Dakota, and Wisconsin.
Barrio, barrio-pueblo, and subbarrio boundaries in Puerto
Rico, census subdistrict boundaries in the Virgin Islands of the United
States, MCD-county and island boundaries in American Samoa, and
municipal district boundaries in the Northern Mariana Islands.
All incorporated place boundaries in Connecticut, Maine,
Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode
Island, and Vermont.
Conjoint incorporated place boundaries in other states;
that is, the boundary separating two different incorporated places.
AIR boundaries.
American Indian trust land, Alaska Native village
statistical area, and Alaska Native Regional Corporation boundaries, at
the discretion of the Census Bureau, insofar as such boundaries are
unambiguous for allocating living quarters as part of Census 2000
activities.
When the features listed above are not available for selection, the
Census Bureau may, at its discretion, approve other nonstandard visible
features, such as ridge lines, pipelines, intermittent streams, fence
lines, and so forth. The Census Bureau also may accept, on a case-by-
case basis, the boundaries of selected nonstandard and potentially
nonvisible features such as the boundaries of National Parks and
National Forests, cemeteries, or other special land-use properties, the
straight-line extensions of visible features, and other lines of sight.
4. Population Thresholds
The Census Bureau proposes the following population criteria for
census tracts (see Table 1):
In the United States, Puerto Rico, and the Virgin Islands
of the United States: 1,500 to 8,000 inhabitants, with an optimum of
4,000 inhabitants.
In American Samoa, Guam, and the Northern Mariana Islands:
1,500 to 8,000 inhabitants, with an optimum of 2,500 inhabitants.
On American Indian reservations: 1,000 to 8,000
inhabitants, with an optimum of 2,500 inhabitants. (The population
criteria for AIRs apply to the entire reservation, including AIRs in
multiple counties or states).
In all counties, for census tracts delineated to enclose
an institution, a military installation, or other ``special place''
population: at least 1,000 inhabitants, with no optimum average or
maximum (no change from 1990). (A special place includes facilities
with resident population, such as correctional institutions, military
installations, college campuses, workers' dormitories, hospitals,
nursing homes, and group homes. A special place includes the entire
facility including nonresidential areas and staff housing units, as
well as all group quarters population.)
Table 1.--Population Thresholds for Census 2000 Census Tracts
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Population thresholds
Area description -----------------------------------------
Optimum Minimum Maximum
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United States, Puerto Rico,
Virgin Islands of the U. S... 4,000 1,500 8,000
American Samoa, Guam, Northern
Mariana Islands.............. 2,500 1,500 8,000
American Indian reservation... 2,500 1,000 8,000
Special place census tract.... none 1,000 none
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5. Comparability and Implementation
As in previous censuses, the Census Bureau generally will not
accept newly proposed census tracts that do not meet the required
minimum population. However, with appropriate justification, the Census
Bureau may grant exceptions on a case-by-case basis. For example, to
facilitate census tract comparability over time, any 1990 census tract
or BNA (except a ``sliver'' census tract/BNA--see 6. Sliver Census
Tracts) that is virtually unchanged (that is, having less than five
percent of the 1990 population affected by a boundary revision) may be
recognized as a Census 2000 census tract even if its population falls
below the minimum required population or above the maximum allowable
population. The Census Bureau, however, recommends combining low
population census tracts and splitting large population census tracts
to meet the goal of providing meaningful small-area data.
6. Sliver Census Tracts
The Census Bureau will not retain, or continue to recognize for
Census 2000, any 1990 ``sliver'' census tracts or BNAs. After the
Census Bureau inserted the 1990 census tracts into the TIGER data base,
sliver census tracts resulted from:
County boundary changes or corrections.
Special land-use boundary changes or corrections (military
reservations, National Parks, and so forth).
Local requests to correct errors in the insertion of 1990
areas into the TIGER data base.
Sliver census tracts usually cover a very small area, and in most
cases involve little or no population or housing. The Census Bureau has
adopted new rules for establishing tabulation geographic areas in
Census 2000 by separating the collection areas from the tabulation
areas. This change will eliminate the need for such sliver census
tracts in Census 2000.
In 1990, the Census Bureau established rules to assign special
numerical suffixes to identify sliver census tracts, generally
beginning with .98 and continuing in descending order. The Census
Bureau applied the suffix to both the original census tract that lost
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territory and the newly created sliver census tract. For Census 2000,
we recommend that local participants dispense with the sliver suffix
for legitimate census tracts, but will not require a change if
specifically requested by the local participant for comparability
purposes.
B. Changes to the Criteria for Census 2000
Most provisions of the census tract criteria remain unchanged from
those used in conjunction with the 1990 census, with the few exceptions
summarized below:
1. The Census Bureau is combining the census tract and BNA programs
to create a single census tract program. The major differences between
the 1990 census tracts and BNAs were: (1) representatives of the states
or Census Bureau staff were responsible for the delineation of BNAs
rather than local census statistical areas committees, and (2) census
tracts were delineated mainly according to population criteria, while
BNAs were delineated to meet data collection criteria based on the
number of housing units rather than population. For Census 2000, the
Census Bureau will contact local officials for the delineation of
census tracts, and there will not be a housing unit criterion, thus
bringing both areas under a single standard.
2. The Census Bureau is increasing the number of governmental units
that have boundaries acceptable to use as census tract boundaries. The
added areas are: all MCDs in Indiana and selected MCDs in Illinois,
Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota,
South Dakota, and Wisconsin; the MCD-county and island areas of
American Samoa; and villages in New York.
3. The Census Bureau now allows officials of Federally recognized
AIRs meeting the 1,000 minimum population threshold to delineate census
tracts without regard to state or county boundaries. Although the
Census Bureau will tabulate data for each state-county-census tract
part, it also plans to provide summed data for all components of each
census tract bearing the same numeric identifier within a Federally
recognized AIR.
4. The Census Bureau will use census tracts only as tabulation
areas, thus allowing late corrections to census tract boundaries as a
result of legal county boundary changes or to correct errors without
having to create unique sliver census tracts for such areas.
Definitions of Key Terms
Alaska Native Regional Corporation (ANRC)--A corporate entity
established under the Alaska Native Claims Settlement Act of 1972,
Public Law 92-203, as amended by Public Law 92-204, to conduct both the
business and nonprofit affairs of Alaska Natives. Twelve ANRCs cover
the entire State of Alaska except for the Annette Islands Reserve.
Alaska Native Village statistical area (ANVSA)--A statistical
entity containing the densely settled extent of an Alaska Native
village that constitutes an association, band, clan, community, group,
tribe, or village recognized pursuant to the Alaska Native Claims
Settlement Act of 1972, Public Law 92-203, as amended by Public Law 92-
204.
American Indian reservation (AIR)--A Federally recognized American
Indian entity with boundaries established by treaty, statute, and/or
executive or court order and over which American Indians have
governmental jurisdiction. Along with reservation, designations such as
colonies, communities, pueblos, rancherias, and reserves apply to AIRs.
Block numbering area (BNA)--A small-area, statistical geographic
division of a county or statistically equivalent area delineated in
1990 instead of and generally geographically equivalent to census
tracts. For Census 2000, the Census Bureau is merging the BNA program
into the census tract program.
Coastal water--Water bodies between territorial seas and inland
water, the encompassing headlands being more than one mile apart and
less than 24 miles apart.
Conjoint--A description of a boundary shared by two adjacent
geographic entities.
Continuous--A description of areas sharing common boundaries, such
that the areas, when combined, form a single piece of territory.
Discontinuous areas form disjoint pieces.
Crews-of-vessels census tract--A census tract created at the time
of enumeration for allocating the shipboard population of merchant and
military ships and identified with a special numeric suffix equal to
.99.
Great Lakes' waters--Water area beyond one mile wide headland
embayments located in any of the five Great Lakes: Erie, Huron,
Michigan, Ontario, or Superior.
Incorporated place--A type of governmental unit, sanctioned by
state law as a city, town (except in New England, New York, and
Wisconsin), village, or borough (except in Alaska and New York), having
legally prescribed limits, powers, and functions.
Inland water--Water bodies entirely surrounded by land or at the
point where their opening to coastal waters, territorial seas, or the
Great Lakes is less than one mile across.
Minor civil division (MCD)--The primary governmental or
administrative division of a county in 28 states, Puerto Rico 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.
Nonvisible feature--A map feature that is not visible on the ground
such as a city or county boundary through space, a property line, a
short line-of-sight extension of a road, or a point-to-point line of
sight.
Special place--A specific location requiring special enumeration
because the location includes people not in households or the area
includes special land use. Special places include facilities with
resident populations, such as correctional institutions, military
installations, college campuses, workers' dormitories, hospitals,
nursing homes, group homes, and land-use areas such as National Parks.
A special place includes the entire facility, including nonresidential
areas and staff housing units, as well as all group quarters
population.
Territorial seas--Water bodies not included under the rules for
inland water, coastal water, or Great Lakes' waters, see above.
Visible feature--A map feature that one can see on the ground such
as a road, railroad track, above-ground transmission line, 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 pose no problem in their location during field
work.
Dated: December 18, 1996.
Martha Farnsworth Riche,
Director, Bureau of the Census.
[FR Doc. 97-2185 Filed 1-28-97; 8:45 am]
BILLING CODE 3510-07-P
