OpenStreetMap improves every day. Its unparalleled global coverage — from roads and rivers to pharmacies, forests, and much more — makes OpenStreetMap a vital resource for building high-quality visual maps and navigation services for every part of the world. And OpenStreetMap data is unlocking details at a scale previously impossible, examining block by block what street networks say about every city in the world. Three recent research projects are stand-out examples of how OpenStreetMap data enables global-scale analysis to inform how we plan and experience urban environments.

Million Neighborhoods

The University of Chicago’s Mansueto Institute built Million Neighborhoods to identify informal settlements, or slums. These neighborhoods are typically dense and severely underserved by roads, power, water, sanitation, and other infrastructure that we all depend on in our daily lives. Slums are typically areas that are hard to get in and out of, compounding the challenges residents of these neighborhoods face. To draw attention to this, the researchers used every building in OpenStreetMap, and calculated just how difficult it was for slum residents to reach the main road network, visualizing the results using colors to highlight the least accessible areas.

Nairobi is a city I know well, and Million Neighborhoods successfully identifies its informal settlements by this method, visualized as red in the map above. However, the analysis also exposes a limitation (and opportunity) of this approach: a dependency on comprehensive coverage in OpenStreetMap. While roads are fully covered in Nairobi, one area called Mathare does not have building footprints in OpenStreetMap, and is therefore not highlighted on the map at all. Good reason to keep mapping!

SprawlMap

SprawlMap from McGill University examines an opposite challenge that can result from unconstrained urban growth: building with too much space. Cul-de-sacs, loops, and huge blocks are the street pattern typical of urban sprawl, design choices that result in an under-connected and car-focused road network. This in turn drives dependency on automobiles, increased CO2 emissions, and social isolation. SprawlMap analyzed street network patterns from OpenStreetMap globally to evaluate their level of disconnectedness, and then complemented that analysis with other data on the geographic expansion of urban areas over the past 30 years. The results highlight a worrying trend: sprawl is accelerating and spreading to new cities across the globe.

The high- quality road network data available through OpenStreetMap has opened up the ability for researchers to perform this type of analysis in nearly every urban setting in the world. Above is Cape Town (where this weekend’s State of the Map was to be, before going virtual). The city follows a typical urban pattern consisting of a dense, well-connected downtown core (the blue area near the western coast) with poorly connected residential sprawl (in purple and red shades) expanding out to the east.

Pedestrians First

Pedestrians First is an initiative by the Institute for Transportation and Development Policy to improve walkability in growing cities. Their analysis uses OpenStreetMap to identify where cities are getting it right. They examine where the street network is dense, compact, and walkable (including car-free areas), and combine those scores with proximity to essential amenities, like schools and medical facilities (from OpenStreetMap data), and access to public transportation (from open data transit schedules).

Interestingly, both urban centers and informal settlements can score well using this methodology, as seen in the green highlighted areas of both the downtown and Soweto township in Johannesburg, South Africa. This suggests that smarter planning, to both reduce sprawl and provide better services to established dense settlements, downtown or informal, could make cities more livable for people across society.

This analysis is similar to well-known services like Walk Score, typically found on real estate sites in the US and Europe, but because the analysis is powered by globally available OpenStreetMap data it can be applied to every city in the world. Like Million Neighborhoods, Pedestrians First also helps identify where OpenStreetMap can improve coverage of things like schools and healthcare points of interest which are not mapped as comprehensively as the road network.

Want to learn more? The annual State of the Map conference is an amazing opportunity to learn more about how OpenStreetMap is used around the world — and it’s happening online this weekend (and will be recorded, if you’re reading this later). Tune in to catch Taylor Reich presenting Pedestrians First, the Million Neighborhoods team is sharing their methodologies, and Jennings Anderson is examining global-scale patterns in how companies are contributing to OpenStreetMap data. Check out the full agenda of State of the Map and see you there.

Maps feature data from Mapbox and OpenStreetMap and their data partners.