OpenStreetMap (OSM) is a free, open geographic database maintained by volunteers. Think Wikipedia, but for map data.

Many public sources publish geospatial data which can be used to improve OSM coverage. However, raw data is not useful without tools to convert and display it in ways which allow contributors to integrate it into the map.

This talk will describe the development of such a tool, the challenges we faced along the way and how we used it to greatly improve public transport mapping for Zagreb and Rijeka.