I have read https://wiki.openstreetmap.org/wiki/OpenRailwayMap/Tagging but I'm a bit confused about how to know if a track can be used in both directions.
For a given way, should I rely on the value of the key oneway and on the value of the key railway:bidirectional ?
And I'm confused about the description of the value "possible" for the key railway:bidirectional. Does it mean a way with that value may be bidirectional or not ?
Thanks for your answers.