Protomaps Blog

Slicing OpenStreetMap Just Got Fresher

Developing software for OpenStreetMap data all starts with the PBF - it’s nodes, ways and relations in the raw, native OSM format. You can make tiled maps, PostGIS databases, or GeoJSON out of PBFs, but those conversions lose some tagging and metadata. With PBF, you get pure OpenStreetMap!

The global OSM.org website provides a weekly copy of the entire planet as one ~80GB PBF. And there’s convenient sites like Geofabrik Downloads for getting just one country of data. These are amazing free resources, with one catch: if you’re contributing data to OSM, those sources are instantly out of date once you upload.

Protomaps Extracts

Protomaps Extracts (previously hosted at protomaps.com/extracts) aims to solve this - it’s a web portal to download minute-updated extracts of OSM for any area, up to 100 million nodes. Well, that’s how it used to be, because this is the last post about Protomaps Extracts here! The service has been migrated to an OpenStreetMap US Community Project, at the url slice.openstreetmap.us, and has:

  • A flashy new logo and domain
  • a new, 100% open source backend and UI, with no API keys or logins required
  • a new GitHub organization SliceOSM outside of the Protomaps umbrella project

New project: SliceOSM

Think about OpenStreetMap as a big pizza party. You can’t eat a whole pizza yourself: you just want a a slice of your local city or country. And with minutely updates, if you add your own toppings, like pineapple or anchovies, your friends get those on their pizza slice too!

By migrating into the OpenStreetMap US nonprofit, this service:

  • Brings the tool to a wider audience outside of just Protomaps map users
  • Increases the open source maintenance “bus factor”
  • In the future, can seamlessly integrate with other OSMUS initiatives such as OSMCha, OpenTrailMap, and MapRoulette

Providing this free service is also supported by hosting credits from the AWS Open Data program.

Project Structure

SliceOSM is built on the OSM Express database for replicating the OpenStreetMap planet by the minute and spatial indexing via S2 cells. It’s intended to succeed Michal Migurski’s original Metro Extracts as well as Mapzen’s Extracts on Demand.

The project is designed to be modular and re-usable, with:

Project Alternatives

SliceOSM is designed for city to country-sized slices, made by human editors. If you need larger areas, bulk slices, or automated use, some alternatives you should look into are: