Making a Better Map: four months of @OpenStreetMap with @MapBox & @foursquare

Jul 10th

Earlier this year, we embraced the OpenStreetMap movement, changing all the maps on foursquare.com to gorgeous maps powered by MapBox. Today, we’re featuring a guest post from MapBox data lead Alex Barth on how MapBox works with the foursquare community and OpenStreetMap to continually make better maps:

foursquare’s switch to OpenStreetMap-based MapBox Streets on the web a few months ago was a huge incentive for the foursquare community to start contributing to OpenStreetMap. People started to let us know about data problems they saw and actively started mapping themselves. Immediately we saw a big bump in contributor growth, and while the foursquare-motivated user influx is just a small part of an already steep curve (in 2011 the OpenStreetMap community grew by 150%), the foursquare community adds a unique perspective. In short, if people check in at a place that isn’t on the map they want to add it; the trick now is to make adding data to the map easier. In the end, this is about making a better map guided by user feedback and data analysis – here’s how we’re doing this.

Analysis: check-ins as priority driver
Even without foursquare users actively reporting to us, we are leveraging user activities for quality control. Anonymized check-in data lets us run global analysis comparing check-ins with OpenStreetMap locations, and more fine-grained analysis placing the number of check-ins on street level maps. In fact we designed an entire site to help us find where OSM was weak compared to where foursquare users check-in: mapbox.com/foursquare-checkins.

Analysis first starts on a very macro level. Here you can see OpenStreetMap data in pink and foursquare check-ins in green on the Indian subcontinent. The overall picture shows solid OpenStreetMap coverage (try the map’s toggle to get a sense of overall coverage).

As we drill into an area, we work with the foursquare API to help quickly focus on which areas on the map are missing data. Here you can see a street level view of Ipanema beach showing foursquare check-in density on MapBox Streets.

25777 check-ins as returned by the Foursquare API in Ipanema beach

Feedback: Enabling a community of mappers
All over the globe, users check in on the street level, where data issues are quick to detect. With over 50% of users outside the United States, we are working around the world to identify data gaps on the map that most affect foursquare users while at the same time helping make it as easy as possible for foursquare users to become part of the larger OSM community. In the past four months we have received 138 map-related support requests through foursquare’s channels. As you can see below, in spite of the huge US user base, the majority of issues are reported from threshold countries. This has everything to do with the traditionally strong footing of OpenStreetMap in the United States and Europe. The result is that,in broad terms, foursquare’s switch to OpenStreetMap draws our attention to coverage in countries like Indonesia, Brazil, India and Mexico.

Tracing satellite imagery
Guided by user feedback and data analysis, we have attempted to respond quickly by working on tracing satellite imagery and fixing street names and label tags. These are some of the cities we have thus improved: Mexico City, Bangkok, Brasilia, Caracas, Fortaleza, Istanbul, Kuwait City, Sao Paulo and Ulaan Bataar – you can find a full list here. Based on your feedback, we have also looked at a whole series of college campuses.

It’s key for us to connect with local communities. As our knowledge of remote places is obviously limited, working with locals is essential. Ultimately it is up to local OpenStreetMap contributors to create a rich map of their surroundings, and to add and maintain points of interest, street names, and so forth. Specifically, satellite tracing has helped us to build fruitful relationships, where we can provide large swaths of data to motivate local contributions.

A great example is Campo Grande, Brazil. Departing from a report by local foursquare user Muzito, we started out improving OpenStreetMap coverage by satellite tracing. A little later we noticed that without our direct interaction, Muzito had figured out how to contribute to OpenStreetMap himself.

Tracing progress after a week. Note how in the meantime Muzito has become active on OpenStreetMap.

Example of street name data, contributed after tracing efforts.

Another good example is Guadalajara, Mexico, where foursquare has received various reports about insufficient street data. Guadalajara was in a pretty good shape on OpenStreetMap already, but there were pockets in the suburbs that we could quickly fill. Soon thereafter, we saw local user groups quickly following up with added information from the ground.

Progress in Guadalajara between March 1st and March 15th of 2012.

Example of street name data, contributed after tracing efforts.

Often a support request is not reporting missing data, but a glitch to be repaired. We fix those right away – for instance this patch of the Tennessee River by Decatur, Alabama.

Fixed: Tennessee River, Alabama

Seeing their neighborhoods on foursquare motivates people to add rich level of detail, like this area of Towson, Maryland that foursquare Superuser 3 Talllguy and his friend Phil have worked on.

These examples illustrate how OpenStreetMap grows: in iterations, by individuals contributing significant amounts of data, building off of each other. Rather than a single player going in and creating full coverage, data is added in layers by many. This all improves and expands OpenStreetMap, and its aim to create and maintain the fertile ground for others to build upon.

Get involved
If you see areas on the map that could use improvement, please report them through foursquare’s support channel. And, if this post has made you curious about OpenStreetMap, learn about contributing at Learn OSM, or check out our open issue tracker to keep up with developments. Have questions or suggestions? We’d love to hear them – just tweet us at @MapBox.

- Alex Barth , data lead at MapBox

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