Support traffic_signals=*

[daganzdaanda]

Recently there was a discussion at ​https://community.openstreetmap.org/t/fussgangerampeln-als-triplet-gemappt/107802 where flohoff argued that the detailed mapping of simple (pedestrian) crossings with a highway=traffic_signals, then a highway=crossing and then again a highway=traffic_signals breaks routers which should give a penalty to a regular highway=traffic_signals but should not do so for a crossing.
During the discussion I noticed ​https://wiki.openstreetmap.org/wiki/Key:traffic_signals for the first time, and thought using this could solve the routing problem.

I think JOSM should add support for traffic_signals=* to the dialogue for traffic lights. It's already in use quite a bit, and it could be useful.

Maybe talk with the iD people, to establish a common understanding for the best value(s) in cases like a crossing for pedestrians and bikes (mentioned in https://josm.openstreetmap.de/ticket/22611 which asks for a validator test). Right now, I guess a light for pedestrian and cyclist crossing could also be done with traffic_signals=pedestrian_crossing and bicycle=yes.

See also the previous https://josm.openstreetmap.de/ticket/17808 (wontfix, but 3 years ago when the tagging was not yet that common)

[skyper]

Wow, the values are a mess. Currently the most common ones are signal (604656), traffic_lights (45796), pedestrian_crossing (13473), crossing (4007) and yes (3934). The rest is below 3000.
What is the difference between signal and traffic_lights? What is the difference between pedestrian_crossing and crossing? What does yes mean?
In general there is a mix of describing the purpose and the type (number and colors of lights). The proper meaning of the values and the general purpose of the key need to be sorted out. Otherwise I do not think this tag should be added to JOSM core.