Designated direction for railway tracks

[Zverikk]

Oneway tag is not applicable to railway=rail (and others, like railway=subway), because there are no legal obstacles to trains going either way. But usually there is a common direction of travel. Mappers use these tags to specify it:

• ​railway:preferred_direction=forway/backward/both
• ​designated_direction=forward/backward/both

These tags are used on 61k and 3.5k objects respectively. Could you please add both, ot at least the first one, to presets and the map style? It would help mappers not add oneway=yes on railway tracks and hint at the correct tagging.

Also it'd be great to validate railway+oneway combilation and suggest a better tagging.

[Klumbumbus]

Hm, currently there are ​88k ways with railway=* + oneway=*, which is more than the 61k ​railway:preferred_direction.
Is there a clear statement from the "railway fraction" of OSM about this tagging topic?

[Zverikk]

Yes, oneway is not formally applicable to railways, since trains are not forbidden by law to go in opposing directions. Oneway is a kind of access: think of it as "access:backward=no". For that reason two railway communities — german and russian — invented these two tags to map designated directions of railway tracks.

[Zverikk]

Also see a comment about oneway here: ​https://wiki.openstreetmap.org/wiki/OpenRailwayMap/Tagging#Railway_Line

[skyper]

There are several solutions (some might be combined):

• ignoring oneway for railway
• using oneway:train=*, oneway:railway=* or similar
• using access tags train:forward/backward or similar
• using the proposed railway:preferred_direction=forway/backward/both and ​designated_direction=forward/backward/both

[Zverikk]

Why invent new tags for what's already on the map?

[skyper]

Replying to Zverikk:

Why invent new tags for what's already on the map?

• What are railway:preferred_direction=forway/backward/both and ​designated_direction=forward/backward/both? New? Not any more I guess.
• train:forward/backward is mentioned on the ​wiki page for designated_direction=forward/backward/both and not new.

Current numbers, all only ways:

1. oneway=* together with railway=*: 98129 ​keys/oneway?filter=ways#combinations
2. railway:preferred_direction=*: 77137 ​keys/railway:preferred_direction?filter=ways
3. designated_direction=*: 14278 ​keys/designated_direction?filter=ways