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ProximityOne GeoBase
• Points ... address locations, schools, hospitals, among others. • Lines ... roads, railroads, water, among others. • Area/polygon ... statistical area boundaries, political area boundaries, water, among others. GeoBase is updated continuously and covers the United States, Puerto Rico and U.S. territorial areas. GeoBase is an extension and update to the Census Bureau TIGER/Line (TLF) shapefiles. Warren Glimpse, founder of ProximityOne, developed the Columbia, MO GBF/DIME file used as the prototype for the TLF program and is developer of desktop and Web-based GIS applications/tools (CommunityViewer GIS, DMILab Tools among others) using TLF data integrated with other wide-ranging data. Augmenting the Census 2010 TLF, GeoBase is developed on a TLF base that benefits from the extensive re-working of the TLF data under the LUCA and MAF programs. Use of improved coordination with local street centerline files, E911 data, and address coverage editing the new TLF data are vastly improved relative to previous versions. Segment Side Geocoding Having intersection-to-intersection road segments coded with address ranges on both sides of the segment has always been an important feature of the TLF data. Since the geocodes (such as census block) are also coded to both sides of the road segment, the TLF data provide a near unique means of correctly assigning an address to a geocode. Filling in Gaps; Keeping Current Even with improvement in the Census 2010 TLF, there are significant gaps and omissions. GeoBase improves the TLF by updating and completing key missing or incorrect data values (address ranges, ZIP codes, other) in a manner that enables a cross-walk back to the original TLF record. Similarly, Census 2010 TLF is obsolete by the time it becomes available for public use. Newer road segments have already been added; others removed; others have had attributes change in value. GeoBase improves the TLF by updating and completing segments in a manner that enables a cross-walk back to the original TLF record. Unique Shapefiles Reflecting Today's Geography As certain geographies change, such as school districts, GeoBase is updated with a cross-walk back to the original TLF record. Point-oriented data that are missing or incorrectly coded, such as schools, are updated. Other geographic lines/points/polygons, not available from Census, are developed using GeoBase. These areas include ZIP Code Area (ZCAs), School Attendance Zones (SAZs) and Census 2000-like urban areas. See more about these geographies below. Line/Segment Shapefiles • All Lines - Major Roads - Detail Roads Point/Marker Shapefiles • All Points - Hospitals - Public Schools - Private Schools Boundary Shapefiles
1 Urbanized Area (UA), Urban Cluster (UC) and ZIP Code Tabulation Area (ZCTA) boundaries will be defined at a later date by the Census Bureau. Provisional UA and UC boundary files will be developed by Proximity in early 2011. See more about Census 2010 urban areas. ZIP Code Area (ZCA), similar to ZCTA, boundaries will be developed by Proximity in early 2011. School Attendance Zones, not developed by the Census Bureau, will be developed in early 2011. See additional information below about UA, UC, SAZ and ZCA boundaries. GeoBase New/Custom Geographic Areas School Attendance Zones. School Attendance Zones (SAZs) are a new type of geography developed by ProximityOne. While individual school districts develop local school attendance zones, the SAZs provide the first set of national scope school attendance zones. SAZs cover the U.S. wall-to-wall. Each SAZ is comprised of a set of unique census blocks. SAZs are defined/contained within a corresponding school district. An SAZ exists for each elementary school. If no elementary school (or only one) exists in a district, the SAZ is the same as the school district. SAZs contain the census block where the school is located (core block). Additional contiguous blocks are assigned the SAZ core block based on geographic and demographic measures and thresholds. Where possible/applicable, SAZs are defined to include whole block groups or census tracts. Urban Areas. Urbanized Area (UA) and Urban Cluster (UC) boundary files are developed by ProximityOne using a methodology similar to Census 2000. The Census Bureau will apply a new methodology to designate urban areas fro Census 2010; those boundaries/designations will become available in 2012. The ProximityOne UA/UC boundaries will be updated annually based in part on the most recent ACS annual updates. ZIP Code Areas. ZIP Code Areas (ZCAs) are similar to the Census Bureau ZIP Code Tabulation Area but vary in some important ways. A census block to USPS ZIP code equivalence file is developed annually through a process that geocodes USPS delivery data. The first of these using Census 2010 census block data will be developed in the period December 2010 through March 2011. The Block-ZCA equivalance file is used to generate the annual ZCA boundaries used for the development of ZCA estimates and projections. Each ZCA is comprised of a set of unique census blocks. Register to keep up-to-date on GeoBase developments. Mention GeoBase in the text section. Additional Information Proximity develops geographic-demographic-economic data and analytical tools and helps organizations knit together and use diverse data in a decision-making and analytical framework. We develop custom demographic/economic estimates and projections, develop geographic and geocoded address files, and assist with impact and geospatial analyses. Wide-ranging organizations use our tools (software, data, methodologies) to analyze their own data integrated with other data. Contact Proximity (888-364-7656) with questions about data covered in this section or to discuss custom estimates, projections or analyses for your areas of interest. |
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