Figure 10-2. Expanding a Census Tract or BNA for Boundary Resolution
When resolving census tract/BNA boundary discrepancies, the Census Bureau expanded the area of a census tract/BNA wherever possible. In Example 1 above, Block 205 was included in Census Tract 6.01 even though the approved census tract plan had included it in Census Tract 6.02. Because Census Tract 6.02 does not contain a Block Group 2, expanding Census Tract 6.02 does not create a discontiguous block group or duplicate any 1990 census block number in that census tract; thus, Block 205 simply becomes part of Census Tract 6.02.
After expanding a census tract/BNA, the Census Bureau flagged the affected census tracts/BNAs by adding special two-digit suffixes (beginning with .98 and then descending) to the basic census tract/BNA numbers. In Example 2, Census Tract 6.01 has been renumbered as 6.98 and Census Tract 6.02 as 6.97.
In Examples 1 and 2, it was possible to expand Census Tract 6.02 to include the affected census block (205). If expanding the census tract would have created discontiguous block groups or duplicate block numbers, the Census Bureau would have created a new, separate census tract/BNA as shown in Figure 10-3.
Census Tracts and Block Numbering Areas10-11
