Downloading TIGER/Line Spatial Data Files :: SAS/GIS(R) 9.4: Spatial Data and Procedure Guide

Defining the Types of TIGER/Line Shapefiles Needed

This section discusses how to differentiate and download the U.S. Census Bureau TIGER/Line spatial data files that you need before importing them into SAS/GIS. There are TIGER/Line shapefiles created between the years 1990 and 2006, which are ASCII files in the Record Type (RT) format. You can also download compressed, zipped TIGER/Line shapefiles created from 2007 to the present.

TIGER shapefiles include many different file types. However, SAS/GIS requires only three file types: EDGES, FACES, and FEATNAMES. These specific shapefile file types are imported into SAS/GIS chains, nodes, and details data sets. You must unzip to extract the TIGER files to your system before you can import them into SAS/GIS.

The U.S. Census Bureau provides two methods for downloading TIGER/Line shapefiles. One is a web-based interface and the other is a File Transfer Protocol (FTP) site. Details of the required file types are next, followed by instructions for downloading both RT and shapefiles with either the web interface or the FTP method.

Required TIGER/Line Shapefile File Types

You do not need to download all types of TIGER/Line shapefiles to create a SAS/GIS map. SAS/GIS reads only the three file types listed in the following table. SAS/GIS requires all three types for each geographical region imported.

Required TIGER File Types
Name	Type	Description	Contents	Link Variable
EDGES	shp	Map features used to create GIS chains	Latitude, longitude, feature type, address ranges, and ZIP codes	TLID 1 3TFIDL, TFIDR
FACES	shp	Attribute values for left/right sides of the chains created from the EDGES shapefile features	FIPS codes for state, county, and place. Also, Census Tract, Block Group, and Block values plus ZCTAs and various Census statistical areas	TFID 2
FEATNAMES	dbf	Feature names assigned to chains created from the EDGES shapefile	Street names, street types, and directional prefixes and suffixes	TLID
1A TIGER Line ID (TLID) is a number that uniquely identifies each feature line in TIGER data. The TLID provides linkage for each line among the various TIGER files. TLID values remain consistent across TIGER release years.
2A TIGER Face ID (TFID) is a number that uniquely identifies each polygon in TIGER data. TFID values remain consistent across various TIGER release years.
3Each line of a polygon edge has a unique TIGER Face ID number referencing the polygons on the left (TFIDL) and right (TFIDR) sides.

The Census Bureau tags each TIGER line and node feature with a unique, permanent ID number. The GIS chain data set observations retain their TIGER/Line ID (TLID) values and the GIS nodes data set observations keep their TIGER Node ID (TNID) values for future reference.

Downloading TIGER/Line Record Type (RT) Files (1990 – 2006)

The U.S. Census Bureau provides an FTP site that enables you to transfer to your system multiple TIGER RT format files simultaneously.

The FTP site is ftp://ftp2.census.gov/geo/tiger/. This FTP site contains various subdirectories organizing the TIGER data by release year, geography, and file type. For example, some year’s files are organized by state. The state folders contain subfolders, one for each of its counties.

For example, the TIGER RT files for the 2000 census for Kent County, Delaware (FIPS code 10001) are in a zip file at: ftp://ftp2.census.gov/geo/tiger/tiger2k/de/tgr10001.zip. The following image shows the contents of the ZIP file.

The RT1 and RT2 file types are required. The RT4, RT5, and RT6 types are optional.

To use the FTP site, connect to the top level with an FTP application. You can use an FTP client application for Windows. Or you can invoke FTP on a DOS, UNIX, or Linux command line.

Downloading TIGER/Line Shapefiles (.shp) (2007 – present)

Interactive Web Method

There are different web pages used to download TIGER files for specific years. Use the main TIGER page to navigate to the download site for a specific TIGER year: http://www.census.gov/geo/www/tiger/index.html.

An example of the main download website for the U.S. Census Bureau layer file type selection for 2012 TIGER/Line shapefiles is: http://www.census.gov/cgi-bin/geo/shapefiles2012/main. This site enables you to select one county at a time to download. There are three layer file types that you need to select. When you finish one file type, navigate back to the Main Download Page to start selecting the next layer file type.

Edges

Note: From the drop-down menu, under the Features heading, submit the All Lines files. You will then select and submit a state. Then from the menu, select a county and click the Download button. Click the Save button when the File Download window is displayed. Specify the location where you want to write the zip file for the EDGES layer.
Faces

Note: From the drop-down menu, under the Feature Relationships heading, submit the Relationship Files selection. In the ensuing list, submit a state selection under the Topological Faces (polygons with all Geocodes) Shapefile heading. Then from the menu, select a county and click the Download button. Click the Save button when the File Download window is displayed. Specify the location where you want to write the zip file for the FACES layer.

CAUTION:

Do not select either the Topological Faces-Area Hydrography or the Topological Faces-Military Installations Relationship File.

SAS/GIS cannot process either of these layer file types.
Featnames

Note: From the drop-down menu, under the Feature Relationships heading, submit the Relationship Files selection. In the ensuing list, submit a state selection under the Feature Names Relationship File heading. Then from the menu, select a county and click the Download button. Click the Save button when the File Download window is displayed. Specify the location where you want to write the zip file for the FEATNAME layer.

CAUTION:

All three layer file types (edges, faces, and featnames) must be downloaded, or error messages are written to the SAS log during the import process.

Place into one folder all of the files extracted from the downloaded ZIP files. All files must be in one folder before attempting to import the files into SAS/GIS.

FTP Method

The U.S. Census Bureau provides an FTP site that enables you to transfer to your system multiple TIGER files simultaneously. This is a faster method than using the web interface to download one file at a time.

This FTP site contains various subdirectories organizing the TIGER data by release year, geography and file type. Note that there are subfolders for the three required file types needed, namely EDGES, FACES, and FEATNAMES.

An example of a U.S. Census Bureau FTP site is the one for 2012 TIGER/Line shapefiles: ftp://ftp2.census.gov/geo/tiger/TIGER2012/. After opening this site in a browser, you can open the EDGES, FACES, and FEATURES subdirectory folders to select multiple states and counties to download.

To use the FTP site, connect to the top level with an FTP application. You can use an FTP client application for Windows. Or you can invoke FTP on a DOS, UNIX, or Linux command line.