01-7690. Urban Area Criteria for Census 2000-Proposed Criteria

AGENCY:

Bureau of the Census, Department of Commerce.

ACTION:

Notice of Proposed Criteria and Request for Public Comment.

SUMMARY:

This Notice provides the Bureau of the Census' (Census Bureau's) proposed criteria for defining urban and rural territory based on the results of Census 2000. It also provides a description of the changes from the criteria used for the 1990 census. The Census Bureau identifies and classifies urban and rural population and delineates urbanized areas (UAs) after each decennial census using criteria that originated with the 1950 census. Since the 1950 census, the Census Bureau has reviewed and revised these criteria for each decennial census. These criteria revisions over the years reflect the Census Bureau's desire to improve the classification of urban and rural population by refining the criteria to take advantage of improvements in data collection and reporting methodologies as well as advancements in technology.

Since the 1990 census, significant technological advancements, together with already existing nationwide block numbering (which was initiated with the 1990 census), has made it possible to classify urban and rural territory on a uniform basis. The Census Bureau proposes a number of significant changes to the criteria for classification of urban and rural population to make use of this opportunity to meet its objective of a uniform result nationwide.

The Census Bureau identifies and tabulates data for the urban and rural population and territory solely for the purpose of statistical presentation and comparison. It does not take into account or attempt to anticipate any nonstatistical uses that may be made of these areas or their associated data, nor does it attempt to meet the requirements of such nonstatistical program uses. Nonetheless, the Census Bureau recognizes that some federal and state agencies are legally required to use the Census Bureau-defined urban and rural classifications for allocating program funds, setting program standards, and implementing aspects of their programs. The agencies that make such nonstatistical uses of the areas and data should be aware that the changes to the urban and rural criteria also might affect the implementation of their programs.

If a federal, state, local, or tribal agency voluntarily uses these urban and rural criteria in a nonstatistical program, it is that agency's responsibility to ensure that the results are appropriate for such use. In considering the appropriateness of such nonstatistical program uses, the Census Bureau urges each agency to consider permitting appropriate modifications of the results of implementing the urban and rural criteria specifically for the purposes of its program. When a program permits such modifications, the Census Bureau urges each agency to use descriptive terminology that clearly identifies the different criteria being applied so as to avoid confusion with the Census Bureau's official urban and rural classifications.

DATES:

Any comments, suggestions, or recommendations concerning this Census 2000 proposed program in this notice should be submitted in writing April 27, 2001.

ADDRESSES:

Address all written comments to the Director, U.S. Census Bureau, Room 2049, Federal Building 3, Washington, DC 20233-0001.

FOR FURTHER INFORMATION CONTACT:

Robert Marx, Chief, Geography Division, Census Bureau, Room 651, WP-1, Washington, DC 20233-7400, telephone [phone], or e-mail ([e-mail]).

SUPPLEMENTARY INFORMATION:

Executive Order 12866

This notice does not meet the criteria for a “significant regulatory action” as specified in Executive Order 12866.

Regulatory Flexibility Act

Because a notice of program criteria is not required by Title 5, United States Code (U.S.C.), section 553 or any other law, a Regulatory Flexibility Analysis is not required and has not been prepared (5 U.S.C. 603 (a)).

Paperwork Reduction Act

This program notice does not represent a collection of information subject to the requirements of the Paperwork Reduction Act, Title 44, U.S.C., Chapter 35.

Criteria

The following criteria will apply to the 50 states, the District of Columbia, and the Commonwealth of Puerto Rico. The Census Bureau may apply these criteria to other areas as well.

I. Census 2000 Urbanized Area and Urban Cluster Definitions

For Census 2000, an urbanized area (UA) will consist of a densely settled core of census block groups (BGs) ^[1] and census blocks ^[2] that meet minimum population density requirements, along with adjacent densely settled surrounding census blocks that together encompass a population of at least 50,000 people, at least 35,000 of whom live in an area that is not part of a military installation. For Census 2000, an urban cluster (UC) will consist of a densely settled core of census BGs and census blocks that meet minimum population density requirements, along with adjacent densely settled surrounding census blocks that together encompass a population of at least 2,500 people, but fewer than 50,000 people, or greater than 50,000 people if fewer than 35,000 of them live in an area that is not part of a military installation. All criteria based on land area, population, and population density will reflect the information contained in the Census Bureau's Topologically Integrated Geographic Encoding and Referencing (TIGER) data base and the population counts from the official Census 2000 redistricting data file.

A. The “densely settled core” of a UA or UC shall include the following:

1. One or more contiguous ^[3] census BGs that have a total land area less than or equal to 2 square miles and a population density of at least 1,000 people per square mile (ppsm) ^[4] (Figures 1 and 6.). (Please note that all illustrative figures are attachments located at the end of the document.)

2. One or more contiguous census blocks that have a population density of at least 1,000 ppsm, if no qualifying BG exists.

3. One or more census BGs that have a land area less than or equal to 2 square miles, a population density of at least 500 ppsm, and that are contiguous with the census BGs and census blocks identified by criterion I.A.1. (Figures 1 and 6).

4. One or more contiguous census blocks that have a population density of at least 500 ppsm and that are contiguous with the qualifying census BGs and census blocks identified by criterion I.A.1., I.A.2., or I.A.3. (Figures 2 and 7).

5. The Census Bureau will include in the core any noncontiguous census BG(s) and/or census block(s) that otherwise qualifies based on population density and land area if it can be reached using a “hop” connection. That is, if the distance to the core is no greater than 0.5 miles, and it is connected to the core by one or more nonqualifying census blocks that:

a. When combined, have the highest population density along the shortest road connection, and

b. Has a combined population density of at least 500 ppsm, or

c. The least populated area (core or noncontiguous census BG(s) or census block(s) has a population greater than or equal to 1,000 (Figures 3 and 9).

6. Census BGs and/or census blocks surrounded by the core, as defined above, provided the BGs or blocks contain fewer than 5 square miles ^[5] (Figure 8).

7. Census BGs and/or blocks that are indentations into the core, as long as the indentation is no longer than 1 mile across the open end, and has a length at least three times greater than the distance across the open end (Figure 8).

B. Census BGs and/or census blocks adjacent to a UA or UC core consists of the following:

1. Territory made up of one or more contiguous census blocks, with a population density of at least 500 ppsm, that are not contiguous to the core, provided that the core of the UA or UC has a population of at least 1,000, and that the contiguous blocks are within the distance of either a jump, a jump plus one or more hops, or an uninhabitable territory connection.

2. The following connection criteria determine the method used for connecting densely settled noncontiguous territory to the qualifying core of a UA or UC:

a. The Census Bureau will include additional noncontiguous area in a UA or UC using a “jump” connection if the noncontiguous area is within 2.5 miles of the main body of a core that has a total population of at least 1,500 people, and is connected to it by one or more nonqualifying census blocks that:

(1) Are adjacent to a road connection;

(2) When combined, have the highest population density along the connection; and

(3) Together with the qualifying outlying blocks/BGs, have a combined population density of at least 500 ppsm (Figures 3 and 10), or the noncontiguous qualifying blocks/BGs has a total population greater than or equal to 1,000.

The Census Bureau will not include additional noncontiguous area in a UA or UC if the connection required to include it is greater than 0.5 miles and the link required to connect the additional area starts from territory already qualifying under criterion I.B.1.b.

b. For territory added using a jump, the Census Bureau will include additional noncontiguous area in a UA or UC that is connected to territory added using a jump by using a “hop” connection if the distance between the UA or UC is within 0.5 miles of qualifying territory, and connected to it by one or more nonqualifying census blocks that:

(1) When combined, have the highest population density along the shortest road connection; and

(2) Together with the outlying qualifying territory, have a combined population density of at least 500 ppsm (Figures 3 and 9), or the noncontiguous qualifying territory has a total population greater than or equal to 1,000. Hop connections are allowed after jump connections as long as the conditions in criterion I.B.1.b. still apply.

c. The Census Bureau will include uninhabitable territory ^[6] to the main body of the core or adjacent qualifying territory if the area to connect it is within 5 road miles, and as long as the 5 miles include no more than 2.5 miles of otherwise habitable territory. In addition, one of the following conditions must be met:

(1) The noncontiguous qualifying territory has a total population greater than or equal to 1,000; or

(2) The overall population density of the linking and noncontiguous qualifying territory (excluding water) has a total population density of at least 500 ppsm (Figure 4).

Hops are allowed after uninhabitable territory connections as long as the conditions in criterion I.B.1.a. still apply.

3. Other territory with a population density of less than 500 ppsm, provided that it:

a. Eliminates an enclave of no more than 5 square miles in the territory otherwise qualifying for a UA or UC when the surrounding territory qualifies on the basis of population density, or

b. Closes an indentation in the boundary of the territory otherwise qualifying for inclusion in a UA or UC if the contiguous territory qualifies on the basis of population density, provided that the indentation:

(1) Is no more than 1 mile across the open end;

(2) Has a length at least 3 times greater than the distance across the open end;

(3) Is closeable by means of a census block boundary located across or close to its open end; and

(4) Encompasses no more than 5 square miles.

4. As a result of the UA and UC delineation, an incorporated place ^[7] or census designated place (CDP) ^[8] , may be partially within and partially outside of a UA or UC. Any place that is split by a UA or UC boundary is referred to as an extended place (Figures 5 and 11).

II. UA and UC Central Places

The Census Bureau will identify one or more central places for each UA and UC (if an incorporated place or CDP exists within the UC) using the following criteria:

A. The UA or UC central place is an incorporated place or CDP with the most population within the UA or UC. Additional places may become UA or UC central places provided that:

1. The place's population within a UA or UC exceeds 50,000 people; or

2. The place's population is at least 2/3 of the most populous UA or UC central place.

III. UA and UC Titles and Codes

The title of a UA or UC identifies the place(s) that is (are) most populated within the UA or UC. All population requirements for places and minor civil divisions ^[9] (MCDs) apply to the population of the place or MCD that is within the specific UA or UC being named.

A. UA and UC Titles

The following criteria are used to determine UA and UC titles:

1. The UA or UC title includes the name of the incorporated place with the most population within the UA or UC (minimum population of 2,500). As many as two additional incorporated place names can be part of the UA or UC title. Additional incorporated place names are added to the title, provided that either the incorporated place's UA or UC population exceeds 250,000 people or the incorporated place has both (1) a UA or UC population of at least 2,500 and (2) a UA or UC population that is at least 2/3 of the total in the most populous place in the UA or UC.

If the UA or UC does not contain an incorporated place having at least 2,500 people, the UA or UC title will include the single name that occurs first from the following list:

a. The nonmilitary CDP with the largest population within the UA or UC, if its population is at least 2,500;

b. The incorporated place with the largest population within the UA or UC;

c. The nonmilitary CDP with the largest population within the UA or UC;

d. The military CDP with the largest population within the UA or UC;

e. The governmental MCD with the largest population within the UA or UC; or

f. A local name recognized for the area by the United States Geological Survey's Geographic Names Information System, with preference given to post office names recognized by the United States Postal Service (USPS).

2. The criterion for the sequence of place or MCD names in the UA or UC title consists of the qualifying names in descending order of their Census 2000 population within the UA or UC.

3. The UA or UC title will include the USPS abbreviation of the name of each state into which the UA or UC extends. The order of the state names is the same as the order of the related place or MCD names in the UA or UC title. For UAs or UCs that extend into states in which there are no place names as part of the UA or UC title, the names of these states are included in descending order of the state's Census 2000 population within the UA or UC.

4. If a single place or MCD qualifies as the title of more than one UA or UC, the largest UA or UC will use the name of the place or MCD. The smaller UA or UC will have a title consisting of the place or MCD name and a compass directional. The compass directional will generally describe the location of the lesser populated UA or UC; for example, a UA titled Allenville and a UC titled Allenville South.

5. If any name in a UA or UC name duplicates a name in another UA or UC within the same state, the name of the county that has most of the population of the largest place or MCD will be appended after the duplicate place or MCD name in parentheses for each UA or UC. If there is no central place or MCD, then the name of the county with the greatest population residing in the UA or UC will be appended. For example, Springfield (Ames County), OH, and Springfield (Jefferson County), OH.

B. UA and UC codes

The Census Bureau will assign a 5-digit numeric code to each UA and UC. The code will be based on an alphabetic sequence of all UA and UC names, and sequenced by state code where names repeat.

IV. Splitting UAs

The Census Bureau uses the geographic structure of metropolitan areas (MAs), which includes metropolitan statistical areas (MSAs), consolidated metropolitan statistical areas (CMSAs), and primary metropolitan statistical areas (PMSAs) to determine when to define separate contiguous UAs.^[10] After delineating the boundary of each UA, the Census Bureau will examine the relationship between the UAs and any MSA, CMSA, or PMSA using the following criteria to determine if the UAs should be split and, if so, where the boundary should be located between these UAs:

A. UA Split Criteria

The Census Bureau will split UAs when the following conditions exist:

1. Two or more qualifying UAs are in different MSAs or PMSAs, and the distance along which their areas are contiguous is less than 3 miles.

The split will occur at the location nearest the MSA or PMSA boundary along which their area of contiguity is less than 3 miles.

2. Two or more qualifying UAs are in different CMSAs, and the distance along which their areas are contiguous is less than 3 miles. The split will occur at the CMSA boundary.

V. Urban and Rural Classification

The Census Bureau will classify as urban all population residing within the boundaries of UAs and UCs. Conversely, the Census Bureau will classify as rural all population and territory that are not within any UA or UC.

VI. Differences Between the Proposed Census 2000 UA Criteria and the 1990 Census UA Criteria

The following summary describes the most important differences between the 1990 census UA criteria and the UA criteria proposed for Census 2000:

A. The Census Bureau will not automatically recognize previously existing UA territory for Census 2000 UA delineation. There will be no “grandfathering” of areas that qualified for earlier censuses. In past censuses, the Census Bureau generally included all territory from previous UA ^[11] delineations. Grandfathering was used extensively in past censuses.

Grandfathering creates a significant impediment when trying to implement UA criteria changes. When areas that would not qualify under new criteria are retained within UAs due to the use of “grandfathering,” this diminishes the effect of the new criteria by retaining areas that the new criteria otherwise would exclude. Therefore, “grandfathering” creates an uneven application of the criteria where similar nonqualifying areas are either retained or excluded from different UAs based solely on “grandfathering.”

B. The Census Bureau will use UCs rather than places to determine the total urban population outside of UAs. Previously, place boundaries were used to determine the urban and rural classification of territory outside of UAs; all incorporated places that had at least 2,500 people had all or part (based on the extended city criteria) of their population classified as urban. The entire land area and population of all CDPs with a population of at least 2,500 people were classified as urban because the extended city criteria did not apply to CDPs. With the creation of UCs, place boundaries are “invisible” when creating and classifying the cores of densely settled population agglomerations.

Urban classification, based solely on the boundaries of incorporated places and CDPs, is very uneven and limited. Urban classification of a place outside of a UA stopped at the place's boundary. Densely settled areas that were adjacent to a qualifying place were not classified as urban. Areas that were densely settled and included more than 2,500 inhabitants, but did not include a place with a population of at least 2,500, were classified as rural. CDPs that were overbounded, containing little densely settled area, but with a population of at least 2,500, always were classified as entirely urban.

The UC concept, based only on census BG and census block density, does not recognize incorporated place or CDP boundaries (except where the boundaries serve as qualifying BG or block boundaries). Densely settled qualifying agglomerations of 2,500 or more people qualify regardless of the total population, or even the existence, of incorporated places or CDPs. This eliminates bias by removing the effect of state laws governing incorporation and annexation or of local participation in the CDP program.

C. The extended city criteria are extensively modified for 2000. Any place that is split by a UA or UC boundary is referred to as an extended place. Previously, sparsely settled areas were examined using density and area measurements to determine whether or not they were excluded from the UA.

The 1990 extended city criteria complemented the previous UA criteria whose focus was to include whole places wherever possible, except for those incorporated places that were very overbounded and very large. The use of different density thresholds within incorporated place territory (100 ppsm rather than 1,000 ppsm outside of places) again was biased based on state laws of incorporation and annexation. The new urban criteria, based solely on the population density of census BGs and census blocks, will provide a continuum of urban areas.

D. The proposed criteria increase the permitted jump distance from 1.5 to 2.5 miles. Jumps between qualifying areas that are less than or equal to 0.5 miles are hops, not jumps. In addition, noncontiguous areas with a population of 1,000 or more qualify for inclusion regardless of the overall combined density of the qualifying and connecting areas.

The increase in the permitted jump distance is proposed as a means to recognize improvements in the transportation network, and the associated changes in development patterns that reflect these improvements, coupled with governmental influence to provide additional “green space” between developments.

The Census Bureau developed the use of hops to extend the urban definition across small nonqualifying census blocks, thereby avoiding the need to designate the break in qualifying blocks as a jump. Most of these hop blocks are developed for nonresidential uses, such as schools, shopping centers, office complexes, industrial parks, and parks or other green space.

E. An indentation in qualifying territory has to be three times longer than the distance across its mouth for its inclusion in a UA or UC. Previously, an indentation only had to be two times longer. Increasing the distance it takes for inclusion of indentations reduces the chances of sparsely settled area along the fringe of a core being classified as urban.

F. The revised uninhabitable jump criteria are more restrictive regarding the types of terrain over which an uninhabitable jump can be made than was permitted under the 1990 census UA criteria.

The new restriction on the types of territory that can be treated as uninhabitable is an attempt to remove ambiguity from the designation of undevelopable or uninhabitable territory. The 1990 census criteria permitted jumps across various types of supposedly undevelopable terrain based on information that normally is not contained within the TIGER data base. For example, floodplains, mud flats, steep slopes, and marshes were designated as undevelopable, but only where a census or local official specifically requested the designation. Because this type of terrain information usually does not exist within the TIGER data base, attempting to use such information under the current criteria is inappropriate. Therefore, the designation of uninhabitable territory is limited to those types of terrain and land use for which the TIGER data base has a complete inventory, such as bodies of water, national parks and monuments, and military installations.

G. The UA central place and title criteria will no longer follow standards predefined by other federal agencies. Previously, many UA central places and titles were based on MA central city definitions set forth by the Office of Management and Budget.

The new MA criteria will be, and always have been, applied later than the UA criteria. To avoid creating a situation in which the 2000 UA or UC central places and titles would need to follow MA central city definitions that were established in the early 1990s, these criteria create an objective zero-based approach.

VII. Effects of the Census 2000 UA Criteria on the 1990 Urban Classification

A. The aforementioned changes in urban criteria may classify as much as three percent (five million) more people as urban than the previous criteria did.

The majority of this increase will come from how urban population is defined outside of UAs. Under the former criteria, urban population outside of UAs was limited to people living in incorporated places and CDPs that had a total population of 2,500 or more. With the change to UC delineation, many densely settled unincorporated areas will be classified as urban for the first time, as well as places having a population fewer than 2,500 that adjoin densely settled territory that brings the total population of the area to 2,500 or more.

The overwhelming majority of densely settled unincorporated areas are located adjacent to incorporated places. Incorporated places in states with strict annexation laws are less likely to annex the densely settled areas that are adjacent to them. Connecticut, Massachusetts, Michigan, New Jersey, New York, and Pennsylvania are states with strict annexation laws. These states will have a higher proportional increase in urban population than those states with liberal annexation laws, such as Alabama, Arizona, Mississippi, Oklahoma, Tennessee, and Texas, where incorporated places are more likely to annex adjacent densely settled areas.

Another element of the criteria that will cause an increase in total urban population is the inclusion into UAs of nearby areas that did not qualify under the former jump criteria. Some areas that were excluded from a 1990 UA because it took two jumps to get to them may be included in a Census 2000 UA because one of the jumps is now classified as a hop. Others may be included because of the increase in the jump distance from 1.5 to 2.5 miles.

B. The total urban area may decrease by as much as 7 percent (6,600 square miles).

The decrease in urban area is due to the removal of the whole place and extended city qualification criteria and the requirement to retain areas that were previously within UAs (“grandfathering”). The decrease results from using a higher density requirement in places (500 ppsm rather than the 100 ppsm used for the 1990 census in extended cities) and the ability to classify CDPs as part urban and rural. States that have liberal annexation laws or overbounded places will notice the most significant decreases in total urban land area.

C. When the Census 2000 UA criteria are applied using 1990 census data, the following four 1990 census UAs fail to qualify using the proposed criteria:

1990 UA	1990 UA population	Proposed criteria population
Bristol, VA	52,563	49,687
Brunswick, GA	50,066	47,282
Dover, DE	50,787	49,355
Ithaca, NY	50,132	49,416

The removal of the whole place qualification criteria is the primary reason why these four areas may fail to qualify as UAs following Census 2000. The 1990 census whole place qualification criteria required that whole CDPs were either included or excluded from a 1990 UA, but there is no requirement under the Census 2000 criteria to include whole CDPs. The 1990 UA qualification of Brunswick, Dover, and Ithaca relied on the inclusion of whole CDPs, but large areas of these CDPs did not meet the population density requirement under the 2000 criteria. Bristol was a 1980 UA, which by virtue of “grandfathering,” qualified all 1980 UA territory as 1990 qualifying territory. In addition, the entire area of Bristol City was included in the UA because it failed to meet the extended city criteria. However, portions of Bristol City do not qualify under the Census 2000 criteria because of low population density.

Even though the 1990 UAs listed above fail to qualify using Census 2000 criteria and 1990 data, they do not necessarily indicate that they will not qualify as Census 2000 UAs. There may have been positive population growth since 1990 in those four areas such that the total qualifying population will rise above 50,000. As stated previously, 1990 census population data were used to determine the qualifying area for these four 1990 UAs. No other 1990 UAs failed to qualify as a result of the criteria changes.

A. Former urban places may be classified as rural under the Census 2000 UC criteria.

The UC criteria do not qualify incorporated places and CDPs that have a population of 2,500 or more as urban based solely on their total populations. Urban classification is based solely on the delineation of a qualifying UC of at least 2,500 people at a density of at least 500. Those places that do not have a qualifying UC of at least 2,500 population based primarily on density will be classified as rural. Places with a population just above 2,500 and those with low densities or dispersed cores may not qualify as urban. Conversely, incorporated places and CDPs that have a population less than 2,500 may be classified wholly or partially as urban when the population outside the place is inside part of a qualifying UC that reaches the 2,500 population threshold.

Dated: February 12, 2001.

William G. Barron,

Acting Director, Bureau of the Census.

Footnotes

1.  A census block group (BG) is a group of census blocks within a census tract whose numbers begin with the same digit; for example, BG 3 within a census tract includes all census blocks numbered from 3000 to 3999.

2.  A census block is an area normally bounded by visible features, such as streets, streams, and railroads, and by nonvisible features, such as the boundary of an incorporated place, minor civil division, county, or other Census 2000 tabulation entity.

3.  Contiguity requires at least one point of intersection.

4.  Population density is calculated by dividing the total population of the census BG or census block by the land area of that BG or block.

5.  Census BGs and/or census blocks are defined as “surrounded” if the boundary of the BG or block completely borders the core. Additionally, bodies of water wider than one mile across are excluded from the equation, so that a census BG and/or census block completely surrounded by the core and excluded water bodies are included in the core.

6.  Uninhabitable territory is defined as territory in which residential development is not possible; that is, it consists of bodies of water, national parks and monuments, and military installations. Water is an example of a topographic situation in which habitation is not possible due to a physical limitation. National parks, such as Yellowstone and Yosemite, and military installations are examples of territory in which habitation is restricted due to governmental regulations. Because the Census Bureau does not maintain an extensive land use data base for the entire country, only the aforementioned land use types, which are included within the Census Bureau's TIGER data base, will be used when distinguishing between habitable and uninhabitable territory.

7.  An incorporated place is a governmental unit designated as a city, town (except in New England and Wisconsin), village, or borough (except in New York and Alaska), and includes all consolidated cities.

8.  A census designated place (CDP) is a statistical equivalent of an incorporated place and represents a locally defined named area. CDPs include comunidades and zonas urbana in Puerto Rico.

9.  A minor civil division is a legal subdivision of a county or statistically equivalent entity. Governmental MCDs exist in Connecticut, Illinois, Indiana, Kansas, Maine, Massachusetts, Michigan, Minnesota, Missouri, Nebraska, New Hampshire, New Jersey, New York, North Dakota, Ohio, Pennsylvania, Rhode Island, South Dakota, Vermont, and Wisconsin.

10.  The Census Bureau considers two UAs to be contiguous if they share a common boundary line (not simply a point), and the area on each side of this shared boundary qualifies for inclusion in its respective UA based on the minimum population density criterion of 500 ppsm.

11.  The Census Bureau did not include previously existing territory within a UA for the 1990 census if the population of the pre-existing UA fell below a total population of 50,000.