Microsoft maps powered by Open data is an ongoing effort to create the best map using data from open sources. The road network on our map is completely generated using Open Street Maps data. In order to measure and improve the data quality of the OSM road data, we are developing a road conflation tool that can match roads from the OSM road network to roads from any given provider. Using this tool, we can generate valuable comparison metrics and reports, but more importantly it allows us to identify roads that are potentially missing from the OSM map. We can also discover differences in road classification and road attributes between the two sources. Our editorial team then contributes to OSM by adding the missing information precisely where it needs to be added.