Three weeks ago, I first talked about connectivity issues in OSM data. More specifically, I introduced an analysis layer showing un- or half-connected islands of the road network, i.e. strongly connected components (SCCs). Read here for more information on SCCs.

A few weeks have passed since the announcement and it is about time to look at the numbers and how they developed over the past weeks. And let me tell you, the numbers are good!

Have a look at the plots. An explanation follows below:

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Team OSRM is happy to announce a new data analysis feature for OpenStreetmap data based on OSRMs great routing capabilities. Over the past weeks, we at Team OSRM received a number of complaints that a certain part of the road network was not route-able and were asked for help. We observed that some of these error were not caused by obviously invalid tagging, but by connectivity issues such as unconnected islands of the road network, sources and sinks. Think of the latter two as one-ways where you can drive in but not out, and vice-versa. There are in fact 1,074,201 such way segments today.

For the impatient: head to OSRMs demo site and activate the ‘small components’ layer or use the routing view of Geofabriks great OSM Inspector to see the visualization.

Big thanks go to Geofabrik for hosting the tile layer that we use.

Strongly connected components

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