In this chapter, the examples we will look at will use spatial data from the OpenStreetMap project, a Wikipedia for maps. It's a convenient data source because it's free for everyone to use and download, and it has global coverage (although the quality may vary). The OSM project itself only serves a full dump (called planet.osm
), which is huge and hard to process. Luckily, third-party services offering smaller extracts exist.
At the time of writing, there were three notable services:
- Mapzen (https://mapzen.com/data/metro-extracts/) offers ready-made extracts of metropolitan areas around the world for anyone, and custom extracts for registered users.
- Geofabrik (http://download.geofabrik.de/) offers continental and country extracts. No sign-in is required.
- BBBike (http://extract.bbbike.org/) offers custom extracts of medium-sized areas (up to 24 million square kilometers or 768 MB of data). No sign-in is required, but a valid e-mail address is...