Table 11-1. Hierarchy of Census Feature Classes for Use as Block Boundaries
Qualifying features ranked from highest to lowest priority:
- Must-hold census block boundary (see “Identifying and Numbering Census Blocks” section)
- Water area (double-line drainage)
- Named, addressable divided roads (by road class)
- Named, addressable undivided roads (by road class)
- Unnamed addressable divided roads (by road class)
- Unnamed addressable undivided roads (by road class)
- Other addressable features
- Feature extensions (manually inserted)
- 1980 statistical/governmental unit boundary (by category)
- Main rail line feature
- Railyard
- Rail spur and other rail feature
- Named perennial stream (single-line drainage)
- Power transmission line
- Pipeline
- Unnamed perennial stream (single-line drainage)
- Named perennial or unclassified canal, ditch, or aqueduct
- Unnamed perennial or unclassified canal, ditch, or aqueduct
- Named intermittent stream or wash (single-line drainage)
- Named braided stream (single-line drainage)
- Unnamed braided stream (single-line drainage)
- Named intermittent canal, ditch, or aqueduct
- Topographic feature (such as bluffs, cliffs)
- Fence line
- Point-to-point line
- Feature extension, other than manually inserted extension
- Other special transport feature
- Physical feature not listed
Note: Examples of features that did not qualify as block boundaries are rail features in tunnel; property line; airport, airfield, or terminal feature; cemetery boundary; golf course boundary; unnamed, intermittent stream or wash; unnamed intermittent canal, ditch, or aqueduct; water boundaries and special water features; and all nonvisible boundary features and statistical boundary features (unless tagged must-hold).
11-12Census Blocks and Block Groups
