Ghost of Midnight

… about neighbors, community and Front Porch Forum

Zip Codes and Polygons

Posted on Wednesday, December 10, 2008 by No comments yet

Defining physical boundaries of neighborhoods is a cornerstone of Front Porch Forum. So we’re interested in local boundaries generally.  Vermont-based Maponics shares a good primer today about ZIP Codes and carrier routes (and they have neighborhood polygons too)…

The ZIP Code and carrier route coding system was specifically developed by the United States Postal Service (USPS) in order to make mail delivery more efficient.  This means that what the average person refers to as a “ZIP Code”, is actually a collection of addresses that have the same 5-digit code assigned to them. The USPS then further splits up each of these ZIP Codes into smaller blocks of addresses: carrier routes. A carrier route literally corresponds to the group of addresses that an individual mail service employee is responsible for delivering to each day.

There are roughly 43,000 ZIP Codes in the US.  These are divided into approximately 600,000 unique carrier routes with, on average, 15 carrier routes per ZIP Code.  Fifty percent of these are PO Box-based carrier routes which do not have actual delivery areas.

ZIP Codes and carrier routes do not tie in to any other US geography. Because of this, they frequently cross city, census tract, county and even state boundaries. The USPS does not provide maps or map data for ZIP Codes and carrier routes. Businesses looking for postal map data to inform their sales territory tracking, direct marketing and other initiatives have to turn to private map data compilers for this information.

Read the full post

Posted in: Community Management, Front Porch Forum, Local Online, Maps, Neighborhood, Vermont

Leave a Reply

Your email address will not be published. Required fields are marked *