Take zipcode boundaries out of uszipcode data, and make it into geojson and topojson files.

Zip code is not actually a geographical designation. Rather, it is where the US Post Office delivers mail. So, no mail delivery, no zip code. So, the maps have holes. The U.S. Census has a more geographical concept of Zip Code Tabulation Areas, or ZCTAs, but they are not in this project.

There is a Makefile for the conversions, but the initial print_zip_geojson.py you have to run yourself.

To print geojson for zip5

$ virtualenv
$ source .venv/bin/activate
$ pip install -r requirements
$ ./print_zip_geojson.py > json/zip5.geojson

To convert to topojson

$ npm install topojson-server
$ export PATH=$PATH:`pwd`/node_modules/topojson-server/bin/
$ export NODE_OPTIONS="--max-old-space-size=8192"
$ geo2topo zipcodes=json/zip5.geojson > json/zip5.topojson

To merge zipcodes into zip3

$ npm install topojson-client
$ export PATH=$PATH:`pwd`/node_modules/topojson-client/bin/
$ topomerge zip3=zipcodes -k 'd.properties.zip5.slice(0,3)' < json/zip5.topojson > json/zip3.topojson

See also

• mapshaper.org
• pypi.org/project/uszipcode/
• github.com/topojson/topojson-client/blob/master/README.md#topomerge