In this second part of our ongoing series, Map Mavin Methods, about finding and using open data, we’ll take a look at how to export layers easily from OpenStreetMap. OpenStreetMap, often referred to as the “Wikipedia of Maps”, is a crowdsourced map of the world whose data is entirely open source and editable. With data being contributed by regular folks around the globe, OSM often has features mapped that are more up-to-date than its proprietary counterparts.
While extracting layers from a giant database such as OSM may sound fancy or complicated, it’s actually very simple (though there certainly are complex processes that can be performed in OSM). In the case of most large cities on earth, one can simply click hyperlinks to downloaded desired spatial layers and other datasets. All of the data you’ll find with the steps outlined here will work great with Map Mavin!
First, go to www.openstreetmap.org/export. Look at the sidebar and click the link, “Metro Extracts”, and you’ll be brought to mapzen.com/data/metro-extracts/. Here you will see a map of the world with transparent red rectangles over the major metropolitan areas. These locations all have extractable data that can be used in Map Mavin, such as roads, city boundaries, etc.
To be clear, one can extract a whole host of data from OSM, and this is by no means restricted to urban areas; but for the purpose of this introductory level series, we’re going to focus on these large cities as it’s an easy intro to finding freely available data online.
For any questions related to Map Mavin and web mapping in general, please don’t hesitate to reach out to Fletcher with the contact information below.