OpenStreetMap as an input source for producing governmental datasets: the case of the Italian geographic institute

The role of Volunteered Geographic Information (VGI) to integrate, update or complement authoritative datasets released by governments has become increasingly important. This work analyses the contribution of OpenStreetMap (OSM), the most popular VGI project, as one of the input sources that the Military Geographic Institute (IGM), one of the Italian governmental mapping agencies, has used for producing the National Summary Database (DBSN). This database, which was recently released for 12 out of the 20 Italian regions, has a schema organised into a hierarchical structure composed of 10 layers, 30 themes and 93 classes, where each geospatial object carries information on the specific data source it was derived from. For each DBSN layer and theme, we first calculated the fraction of objects derived from OSM in all the Italian regions and related provinces. We found a heterogeneous picture with OSM contribution generally being limited, with the exception of few regions and layers/themes where the DBSN was almost exclusively derived from OSM. An in-depth comparison between the DBSN and OSM building datasets showed that OSM building completeness is varying across Italian regions and provinces, but in all regions there are buildings in OSM that are not included in the DBSN. The work shed light on the opportunities and obstacles for OSM to become a primary input source for the production of governmental datasets.