The Spatial Metadata Identifier (SMID) in the All Lines shapefile identifies the source of the coordinates for each line segment and provides the link between the TIGER/Line Shapefile and the source and horizontal spatial accuracy information. Please note that the horizontal spatial accuracy, where reported in the metadata, refers to the realigned street features identified as matched to a positionally accurate source file with that accuracy. Individual feature-based horizontal spatial accuracy does not apply to the entirety of the TIGER/Line Shapefile.

The North American Datum of 1983 was used in the 48 contiguous states, the District of Columbia, Alaska, Hawaii, (only Oahu Island within Honolulu County, HI (15003)), Puerto Rico, the Virgin Islands of the United States, and the Pacific Island Areas. Even though a NAD83 PRJ file will accompany every TIGER/Line Shapefile, there are a few island areas in TIGER that have not gone through the NAD83 transformation process and are still in local astronomic datums. For detailed information regarding these exceptions please refer to the metadata that is included with each TIGER/Line Shapefile.

If you need further information concerning the content of the TIGER/Line Shapefiles, please contact the Geographic Products Branch, Geography Division at tiger@census.gov.