Description of the 2008 Relationship Tables

The All Lines shapefile (edges.shp) contains the geometry and attributes of each 
topological primitive edge.  Each edge has a unique TLID (TIGER/Line Identifier) value.  
The left and right faces for an edge can be determined by linking on the TFIDL (left) or 
TFIDR (right) attribute to the TFID attribute in the Topological Faces relationship table 
(faces.dbf).

The Address Ranges relationship table (addr.dbf) contains the attributes of each address 
range.  Each address range has a unique ARID value.  The edge to which an address 
range applies can be determined by linking to the edges shapefile on the TLID attribute.  
Multiple address ranges can apply to the same edge (an edge can have multiple address 
ranges).

The Address Range-Feature Name relationship table (addrfn.dbf) contains a record for 
each address range-linear feature name relationship.  The purpose of this relationship file 
is to identify all street names associated with each address range.  An edge can have 
several feature names; an address range located on an edge can be associated with one or 
any combination of the available feature names (an address range can have multiple 
feature names).  The address range is identified by the ARID attribute, which can be used 
to link to the Address Ranges relationship table.  The linear feature name is identified by 
the LINEARID attribute that relates the address range back to the featnames.dbf table.

The Feature Names relationship table (featnames.dbf) contains a record for each feature 
name-edge combination, and includes the feature name attributes.  The edge to which a 
Feature Names relationship table record applies can be determined by linking to the All 
Lines shapefile on the TLID attribute.  Multiple Feature Names relationship table records 
can link to the same edge, for example, a road edge could link to US Hwy 22 and 
Rathburn Road.  The linear feature to which the feature name applies is identified by the 
LINEARID attribute.  Multiple feature names may exist for the same edge (linear 
features are not included in the data set, but could be constructed using the All Lines 
shapefile and the relationship tables).

The Topological Faces relationship table contains the attributes of each topological 
primitive face.  Each face has a unique TFID value.  The face geometries can be built 
from the All Lines shapefile using the edges’ left and right face relationships.  The 
geometries of each geographic entity can then be built by dissolving the face geometries 
on the appropriate attribute(s) in the Topological Faces relationship table.

The Area Landmark shapefile (arealm.shp) contains the geometry and attributes of each 
area landmark.  Each area landmark has a unique AREAID value.

The Topological Faces-Area Landmark relationship table (facesal.dbf) contains a record 
for each face-area landmark relationship.  The face to which a Topological Faces-Area 
Landmark relationship table record applies can be determined by linking to the 
Topological Faces relationship table on the TFID attribute.  The area landmark to which a 
Topological Faces-Area Landmark relationship table record applies can de determined by 
linking to the Area Landmark shapefile on the AREAID attribute.  A face may be part of 
multiple area landmarks.  An area landmark may consist of multiple faces.

The Area Hydrography shapefile contains the geometry and attributes of each area 
hydrography feature.  Each area hydrography feature has a unique HYDROID value.

The Topological Faces-Area Hydrography relationship table contains a record for each 
face-area hydrography feature relationship.  The face to which a Topological Faces-Area 
Hydrography relationship table record applies can be determined by linking to the 
Topological Faces table on the TFID attribute.  The area hydrography feature to which a 
Topological Faces-Area Hydrography relationship table record applies can be determined 
by linking to the Area Hydrography shapefile on the HYDROID attribute.  A face may be 
part of multiple area water features.  An area water feature may consist of multiple faces.

The Other Identifiers relationship table contains external identifier codes, such as 
National Hydrographic Dataset (NHD) codes and individual county identifiers.  The edge 
to which an Other Identifiers relationship table record applies can be determined by 
linking to the All Lines shapefile on the TLID attribute.  Not every TLID has an external 
identifier associated with it, and some TLIDs may have more than one.