Census.gov to release TIGER data in shapefile format
Starting in January 2008, the Census Bureau will begin releasing TIGER spatial data in
shapefile format. A revised record layout for the shapefiles and associated relationship files is now available in [PDF] and [TEXT] formats. This document was most recently updated on December 13, 2007.
What is TIGER®?
The term TIGER® comes from the acronym Topologically Integrated Geographic Encoding and Referencing which is the name for the system and digital database developed at the U.S. Census Bureau to support its mapping needs for the Decennial Census and other Bureau programs…. [MORE]
I’ve been using TIGER streets data for years as the cheap man’s way to get streets in. TIGER has been known for very crude streets and certainly not ones you could use in a 911 system because it is not accurate to true centerlines. The Census bureau has been preforming map modernization on streets and other layers recently and there are significant improvements, though in many areas it still isn’t quite good enough…. [MORE]
How can a county or city benefit with the new TIGER GIS data in shapefile format? Now you won’t have to use a special extraction utility to get the data into shapefile format. In fact, in ArcGIS there is a batch utility that will allow you to reproject an entire county’s shapefile dataset. Every shapefile produced contains an associated projected (PRJ) file. All Census Bureau generated shapefiles are in GCS NAD83, and each PRJ file will contain the following:
GEOGCS["GCS_North_American_1983", DATUM["D_North_American_1983", SPHEROID["GRS_1980",6378137,298.257222101]], PRIMEM["Greenwich",0], UNIT["Degree",0.017453292519943295]]
So I guess it’s about time. Thanks Census guys.
And if you are interested, GEO-Jobe has the most recent Census data for (2006 second edition) TN already reprojected. It’s available in shapefile format for all available layers.
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