Towards quality metrics for openstreetmap

Volunteered Geographic Information (VGI) is currently a “hot topic ” in the GIS community. The OpenStreetMap (OSM) project is one of the most popular and well supported examples of VGI. Traditional measures of spatial data qual-ity are often not applicable to OSM as in many cases it is not possible to access ground-truth spatial data for all regions mapped by OSM. We investigate to develop mea-sures of quality for OSM which operate in an unsupervised manner without reference to a “trusted ” source of ground-truth data. We provide results of analysis of OSM data from several European countries. The results highlight spe-cific quality issues in OSM. Results of comparing OSM with ground-truth data for Ireland are also presented. 1