Digital Map Database


The ProximityOne Digital Map Database (DMD) is comprised of point, line and area shapefiles and related datasets covering the United States. DMD is used to associate virtually any type of subject matter data to the geographic infrastructure down to the address and intersection level of detail. Vector-based geography include:
  • Points ... address locations, schools, hospitals, other related
  • Lines ... roads, railroads, water, other related.
  • Area/polygon ... statistical & political area boundaries, other related
Derived resources:
  • Census Tract/Block Street Index

DMD is updated continuously and covers the United States, Puerto Rico and U.S. territorial areas.

DMD 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 (CVXE GIS tools using TLF data integrated with other wide-ranging data).

Augmenting the Census 2010 and more recent vintage TLF, DMD 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 and successor TLFs, there are significant gaps and omissions. DMD 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 TLFs are obsolete in many respects by the time they becomes available for public use. Newer road segments have already been added; others removed; others have had attributes change in value. DMD 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, DMD 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 DMD. These areas include ZIP Code Area (ZCAs), School Attendance Zones (SAZs) and Census 2000-like urban areas.

Line/Segment Shapefiles
  • All Lines
    - Major Roads
    - Detail Roads

Point/Marker Shapefiles
  • All Points
    - Hospitals
    - Public Schools
    - Private Schools

Boundary Shapefiles
  U.S. & State   Core-Based Statistical Area   City/Place   ZIP Code Area
  Congressional District   Metropolitan Division   County Subdivision   Census Tract
  County   Urbanized Area/Urban Cluster   School District   Census Block Group
    Urban Cluster   School Attendance Zone   Census Block

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