Do we really NEED railway=tram_crossing resp tram_level_crossing?

[ManuelB701 (Manuel B.)]

@Minh_Nguyen

That proposal legitimized the practice of mapping street-running railway tracks as separate features crisscrossing the roadway, as an exception to the physical separation principle, in order to model track geometry more accurately.

Yeah, I was aware of this separation between road and rail (and fixing that in a couple places).

@Minh_Nguyen

Around the same time, railway=tram_crossing and railway=tram_level_crossing were informally discussed on the tagging list and on the Russian forum, but you’re right that there wasn’t a formal written proposal on the wiki.

Good to see it wasn’t a service=driveway2 situation. Still fairly rushed, though (e.g. no link to these pages whatsoever up until just now — both are very important), else it felt like these tags were pulled out of someone’s backside.

@Minh_Nguyen

To keep maps and navigation systems from “crying wolf” about these abstract crossings, iD limited railway=crossing and railway=level_crossing to heavy-rail crossings, distinguishing tram crossings.

I can slowly see this point. I can’t quite fathom this because the separation was largely past my registering (albeit not as clean everywhere, I should note) and moreover, there also are lateral crossings which would create “unnecessary” tramway crossings, though I also remember a period where StreetComplete asked the max height at any level crossing before it was disable at any tramway just for the amount of crossings.
(On that aside, in case railway=tram_crossing^[1] ever gets deprecated, the rule for street running tramways should be transplanted to railway=tram_crossing.)

@Minh_Nguyen

Moreover, trams have different safety characteristics than locomotives, and in many cities, real tram crossings look different than real heavy rail crossings.

There is a reason why I see tramways as a form of light rail and at least in Germany, tramway crossings only need to be protected by barriers (at most single barrier, to be precise) for automated train operation and IIRC that is only needed at busy intersections.^[2] Otherwise, the only protection needed are a saltire for an “exclusive” trackbed (Besonderer Bahnkörper) or none at all if considered street running (Straßenbündiger Bahnkörper).
And of course, there also is the issue railway=light_rail which itself is problematic in what even constitutes “light rail” but that’s really just a RL issue than an OSM issue per-se regarding the definitions of light rail. Where it does affect OSM is that, while not as common as with normal tramways, street running also is a thing (being one the main strength compared to proper railways which are legally forbidden to do so or at least require the streets to be cleared) but the default are full railway crossings instead of whatever fits the current situation.

@Minh_Nguyen

That said, from the edits in Germany, we can see that the use of the word “tram” is problematic, because it implies to some mappers that any tram–road crossing node would qualify.

In all fairness, this is a mixture of confusing definitions, bad naming but also of users who don’t read the tags descriptions (points at earlier me).
(This is why I justify the use of crossing:saltire=yes for any tramway crossing.)

@Minh_Nguyen

From some of the discussions surrounding these tags, it sounds to me like the intention was for data consumers to ignore them, or at least deemphasize them.

Not that it of course make them any less of hack tags (in fact, that strengthens the point).

@Minh_Nguyen

The challenge with these “tram crossings” would be to clearly but succinctly describe the difference, since there are so many edge cases.

In all fairness, if railway=tram_crossing weren’t a thing, I’d simply go with railway=crossing for any non-street-running tramway alongside a combination with railway:saltire=* (and make the tag necessary for QA at least for railway=tram/light_rail).

---

1. resp. railway=tram_level_crossing but mentioning that all the time would simply bloat the post ↩︎

2. More accurately, if the trackbed is considered “independent to any highway” (Unabhängiger Bahnkörper) which typically means grade separation but not always. ↩︎