Rethinking the buffering approach for assessing OpenStreetMap positional accuracy

Abstract

OpenStreetMap (OSM) is a free source of spatial data based on crowd-sourcing. Although OSM data are widely used in applications such as the generation of 3D models, routing and navigation, the quality issue is still one of the significant concerns when using these data. Extensive studies have focused on assessing the quality, especially the positional accuracy, of OSM data. One method for assessing accuracy is the buffering approach where a buffer is created around a validated road network using a predefined buffer radius. The percentage of OSM road lengths that lie within this buffer is then calculated. While existing studies have used the buffering approach, the method itself has not been evaluated either theoretically and experimentally. It is found that the percentage of OSM road length calculated based on the buffering approach may be imprecise if the validated road network and the OSM road network are not matched one-to-one. Therefore, this study suggests that it is necessary to first match the OSM road network with the validated road network before using the buffering approach.