Tagging habits for mapping public transport stops in OSM vary greatly from region to region. Next to the original tagging scheme there are the PTv2 scheme and some non-standard tagging habits. For data consumers it's hard to simply get a list of, say, all bus stops in a city. For some stops there's only a stop position on the road, others only have a platform, and some are mapped as a combination of pole, platform and stop position. PTSA (Public Transport Stop Analysis for OSM) on the one hand visualizes all public transport stop related data available in OSM across all modalities and, thus, helps to analyze local tagging habits and to find mistakes in the data. On the other hand, PTSA automatically generates groups of stop objects belonging to one and the same stop, whether it's mapped as a single object are as a combination of two or three objects. PTSA is updated once per day and has worldwide coverage. See https://gauss.whz.de/ptsa.

The talk provides an introduction to PTSA for data analysis and quality assurance and discusses some technical issues faced during the development of the project.