U.S. Geocoding Databases

The U.S. geocoding databases contain the spatial data necessary to perform address standardization and geocoding. You must install at least one of these databases.

• Centrus Enhanced Geocoding—This database consists of TIGER data provided by the U.S. Geological Survey and address data provided by the U.S. Postal Service.
• TomTom Geocoding—This database provides more up-to-date data than the Centrus Enhanced Geocoding database. It requires an additional license. The data is provided by TomTom, a third-party provider of spatial data, and postal data from the U.S. Postal Service.
• HERE Geocoding—This database provides more up-to-date data than the Centrus Enhanced Geocoding database. It requires an additional license. HERE data is provided by HERE, a third-party provider of spatial data. For more information about these databases, contact your sales representative.
• ZIP + 4 Centroid—This database provides only address standardization and ZIP + 4 centroid matching. It does not provide street-level matching.

These databases use proprietary files called SPD files. For ZIP Code centroid matching, the file us.Z9 contains all the centroid info for all states and normally has a z9 extension.

Each geocoding database has an optional Statewide Intersections Index. The Statewide Intersection Index is designed to enable fast intersection identification on a statewide basis. For example, the Statewide Intersection Index will allow the database to search for "1st and Main St, CO" and return a list of possible matches in Colorado more quickly than searching the entire geocoding database for each instance of the intersection.