Census Tract Program for Census 2000Proposed Criteria

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

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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 ``[email protected].''

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]

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