A method, apparatus and computer readable storage medium are provided for determining a path of a mobile device in a public transportation building. In a method, a plurality of position data items are collected. Each position data item represents a respective position parameter captured by a mobile device that is indicative of a coarse position of the mobile device when the respective position parameter was captured by the mobile device. The method also includes determining, at least partially based on the position data items and public transportation data, an arrival area and/or a departure area of the public transportation building as start and end, respectively, of the path. The method further includes determining, at least partially based on building map data, a plurality of potential paths of the mobile device in the public transportation building starting at the arrival area and/or ending at the departure area.