Schools in Dakar
Getting more out of Open Street Maps?
At Ona, we’ve always been big fans Open Street Maps (OSM). What’s always bugged me is I felt (like many groups), we’ve failed to fully understand and leverage the incredible wealth of data that OSM represents. Sure, our basemaps are powered with OSM data. And yes, we encourage partners to contribute data back whenever possible, but surely couldn’t we be using OSM to do more?
The problem for me with OSM is that is always seemed a bit “flat”. I knew the data in OSM is incredibly rich. I could clearly see a neighboring school on a map, for example, but I just didn’t fully grasp how to access it’s underlying properties. Key features remained “baked” into the map. Discovering OSM Overpass and finally understanding OSM as a result, completely changes everything for me.
What is OSM Overpass?
Overpass is a third party API that helps expose and extract specific features from OSM. Using a powerful query language you can extract specific features from OSM for a specified area. This makes it easy to extract all the towns, roads or health facilities from an area (with their properties) in a format that can be converted into common geospatial formats like shapefiles or geojson for external analysis and visualization. Using the overlay query you can even do things like extract all the gas stations along a particular road.
One of the challenges with Overpass is the query language, while powerful, has a pretty steep learning curve. Luckily, there is a great tool called Overpass Turbo that helps simplify the query building process and instantly lets you visualize the search results on a map. I found it to be an invaluable resource to understanding what’s possible with Overpass better.
So why is this so exciting?
OSM goes from an open alternative to Google Maps to potentially the canoncial source for shared locations. Or if leveraged properly, the foundation for a global check-in service. At Ona we’ve always asked ourselves, if I could check-in to a restaurant or bar to rate it, why can’t we do the same for a rural clinic in Africa? The answer is simple. We’ve lacked a shared sense of where things are. From experience, I know trying to rely on names to uniquely identify rural communities is completely unfeasible. And most critical infrastructure like water points simply lack names. GPS points are great for creating a dot on the map but don’t serve you well if you are interested in tracking changes over time.
We’ve explored the check-in idea down a number of paths. Our mistake was not to recognize that OSM provides not only the technical infrastrucure required for such a service but, as an invaluable common good, OSM IS the place where this open data should live.
At Ona, we’re trying to build towards a future where aid and humanitarian response efforts will be better coordinated. The ability to accurately share a common sense of location is critical to that.
To this end, we have been working with the American Red Cross and SpatialDev on a project that moves us one step closer to making the idea of “OSM check-ins” a reality. We’ll share more about the exciting progress and it’s implications shortly.