piebro/osm-data huggingface dataset:
Kevin Kofler (2023-06-15 12:35:14+00:00): > aber im engeren und Wiki-Sinn steht es wie im Deutschen für ein mehr oder weniger geradliniges Objekt

Das ist völliger Unsinn: Nirgends auf:

* https://wiki.openstreetmap.org/wiki/Tag:tunnel%3Dculvert
* https://wiki.openstreetmap.org/wiki/DE:Tag:tunnel%3Dculvert
* https://wiki.openstreetmap.org/wiki/DE:Key:tunnel
* https://wiki.openstreetmap.org/wiki/Key:tunnel

ist von "geradlinig" die Rede. Auch z.B. Eisenbahntunnel sind oft alles andere als gerade, siehe z.B. den in Bau befindlichen Semmering-Basistunnel. Zudem ist für OSM ausschließlich die englischsprachige Definition relevant.

Zudem fehlt mit deiner "Korrektur" die Information, daß der Bach in diesem Bereich unterirdisch verläuft, komplett, weil du keine Alternative für den nach deiner Privatmeinung "falschen" tunnel-Tag vorzuschlagen hast. Damit hast du Information gelöscht = Vandalismus.

Ein Revert-War:
https://www.openstreetmap.org/changeset/137367465
ist jedenfalls KEIN konstruktiver Beitrag.
Kevin Kofler (2023-06-15 12:38:40+00:00): > Ich finde es übrigens bemerkenswert, wie viele Leute sich hier wichtig machen und den Kanal umtaggen, aber selber gemappt hat von euch noch keiner einen Kanal, dazu seid ihr zu faul!

Um zu erkennen, daß ein unterirdisch verlaufender Bach einen Tag braucht, der ebendies beschreibt, muß ich nicht dort gewesen sein.
Kevin Kofler (2023-06-15 12:41:16+00:00): Siehe https://www.openstreetmap.org/changeset/137368001 für die von fkv angezettelte Revert-War.
Negreheb (2023-06-15 12:48:55+00:00): Ein bisschen Respekt gegenüber anderen Mappern ist schon angebracht! Wir wollen hier alle schließlich eine korrekte Datenbank erstellen. 

https://wiki.openstreetmap.org/wiki/Key:tunnel Hier steht nichts von 'gerade' oder Eingängen. 
> Das hier ist ein Kanal mit einem Ausgang zum Liesingbach hin, aber keinem Eingang, somit kein Tunnel.

Nur, weil du nicht weisst, wo der Eingang ist oder nur, weil der Eingang unter der Erde unzugänglich ist oder unter Wasser macht es das nicht weniger zu einem Eingang.
Negreheb (2023-06-15 12:53:20+00:00): Das OSM-Wiki verweist bei der Erklärung übrigens auch weiter auf das normale Wiki mit https://en.wikipedia.org/wiki/Tunnel 

"A tunnel may be for foot ..., or for a canal. ... Some tunnels are used as sewers or aqueducts to supply water for consumption or for hydroelectric stations. ..." 

Das ist doch hier recht zutreffend, oder etwa nicht?
Luzandro (2023-06-15 12:57:03+00:00): Ein waterway=drain ist nicht unterirdisch. Auch layer ist nur eine relative Angabe für überlagernde Abschnitte, aber ein negativer Wert sagt nicht aus, dass es sich um etwas unterirdisches handelt. Und ab wo ist dann ein U-Bahn-Tunnel kein Tunnel mehr, wenn er unterirdisch endet?
KaiRo (2023-06-15 12:59:04+00:00): Wenn du ein besseres Tagging für einen "eingehausten" Bacj hjast, dann kannst du es gern hier verwenden, aber einfach reverten bringt nix. Ich hab bein Vorbeifahren dort nie genau geschaut, aber wenn das ein "eingehuster" bach ist, der also in Rohren verläuft, dann ist ein Tagging wie bei der Wien im Bereich Karlsplatz sinnvoll, und dort ist tunnel=yes verwendet worden.
Negreheb (2023-06-15 13:01:18+00:00): Ich persönlich wäre dafür, dass wir das hier reverten, zurück zu tunnel=*, da wir hier eine Mehrheit haben, die das richtig findet und das auch vorher schon drinnen war (von dir selbst eingetragen - korrekt, meiner Meinung nach) und du dann eine Diskussion im Forum oder auf der Mailingliste über das Thema eröffnest. Vielleicht gibts dann ja neue Infos und wir sagen dann auch "Ja, okay, wir sollten das Wiki wirklich umschreiben."

Und wenn du eben keine Zustimmung bekommst, müsstest du dich dann halt auch an das halten, auf was sich die lokale Community einigt. Es ist halt ein Community-Projekt und nicht deine persönliche Spielwiese. 

Und ob der Kanal jetzt zwei oder drei Wochen länger noch ein tunnel=* ist, sollte ja wirklich egal sein.
Kevin Kofler (2023-06-15 13:14:02+00:00): Der tunnel-Tag wurde ursprünglich nicht von fkv eingetragen, sondern von Johannes M.

(Damit ist das hier auch fkvs erster Revert in der Angelegenheit, und sein Revert meines Reverts bereits der zweite aufeinanderfolgende.)
fkv (2023-06-15 13:23:42+00:00): Nein, es ist kein Bach, sondern ein Kanal! Um das herauszufinden hätte es gereicht, mich einfach zu fragen. Von mir ist alles öffentlich, von der Mailadresse bis zur Telefonnummer. Wer weiter über das Tagging diskutieren will, der möge sich bitte vorher den Kanal vor Ort anschauen, mit Stirnlampe und evtl. Gummistiefeln. Ansonsten vertraut bitte darauf, dass ich mich besser als ihr mit dem Tagging unterirdischer Objekte auskenne. Ich kartiere seit 13 Jahren für OSM und bin beim Höhlenverein für künstliche Anlagen zuständig. Ich bin immer bemüht, mein Wissen weiterzugeben, und nehme auch gern Anregungen entgegen. Aber ich habe keine Lust mit Leuten herumzustreiten, die keine Ahnung habe, aber glauben mich belehren zu können oder meine Objekte hinterrucks umtaggen.
KaiRo (2023-06-15 15:12:18+00:00): Wenn es ein Abflusskanal für Regenwasser ist, dann ist es m.E. wie ein "eingehauster Bach" zu betrachten (da es auch das ist, ob ein bacch künstlich oder natürlich angelegt ist, spielt IMHJO keine Rolle). Und so wie bei der Wien sehe ich damit tunnel=yes als gerechtfertigt. Aber obwohl ich dort mit dem Rad öfters mal vorbei fahre, werde ich mich nicht drum streiten, das ist mir zu sehr eine Verschwending meiner Energie.
Negreheb (2023-06-15 15:46:13+00:00): Es freut mich, dass wir zu einem gemeinsamen Schluss gekommen sind fkv, dass das ein Kanal ist und damit auch als "tunnel=*" getagged werden sollte. 

Passend  zum OSM-Wiki https://wiki.openstreetmap.org/wiki/Key:tunnel "tunnel=* is used for , ...canals, etc. that run in a tunnel. " und auch passend zum normalen Wiki https://en.wikipedia.org/wiki/Tunnel "A tunnel may be for foot or ... for a canal."

Schön, dass wir hier eine Einigung erzielen konnten :)

Revert in https://www.openstreetmap.org/changeset/137378350 durchgeführt
kuhni74 (2023-06-15 17:05:02+00:00): die gleiche Diskussion gibt es gerade auf https://www.openstreetmap.org/changeset/132653902
Woazboat (2023-06-15 19:34:30+00:00): Ob das ein Bach, ein Kanal oder ein, zwei oder mehrere Eingänge hat ist völlig egal. Wenn es unterirdisch geführt wird ist ein `tunnel=*` Tag richtig und notwendig.
SomeoneElse (2023-07-07 20:03:59+00:00): Hello fkv,
The golden rule of OSM is that if lots of people are telling you that you are wrong, you probably are.
Here https://osm.mapki.com/history/way/1021250484 suggests that there is no-one on your side in this particular argument.
If you _still_ think that you are correct, please take the discussion to https://community.openstreetmap.org/c/communities/at/59 .
Best Regards,
Andy Townsend, from OSM's Data Working Group.
SomeoneElse (2023-07-07 20:04:30+00:00): Hallo fkv,
Die goldene Regel von OSM lautet: Wenn Ihnen viele Leute sagen, dass Sie falsch liegen, dann liegen Sie wahrscheinlich falsch.
Hier deutet https://osm.mapki.com/history/way/1021250484 darauf hin, dass in diesem speziellen Argument niemand auf Ihrer Seite ist.
Wenn Sie immer noch der Meinung sind, dass Sie Recht haben, führen Sie die Diskussion bitte zu https://community.openstreetmap.org/c/communities/at/59.
Mit freundlichen Grüßen,
Andy Townsend von der Datenarbeitsgruppe von OSM.
fkv (2023-07-08 00:38:58+00:00): @SomeoneElse I can find no such "golden rule" in the wiki, and I bet there never was. A rule that is in the Wiki is the "on the ground rule" (https://wiki.openstreetmap.org/wiki/Disputes#On_the_Ground_Rule). I'm the only mapper who has been inside this sewer and knows what it looks like. The others are armchair mappers who have not even been at the entrance. I already explained to them that this is a sewer and why it's not a tunnel, but they didn't even care to read, and were still talking about a brook. It's ridiculous.

Are you sure you got your forum link right? It does not lead to any discussion about sewers or tunnels. Both are not specific to Austria anyway. The lack of a forum or ML discussion on this topic indicates that the people who started quarreling aren't independent of each other, but it's only one (Negreheb) who brought in all of his friends. Otherwise they couldn't have posted all within just a few hours. There's no way they would ever have come across this sewer, let alone all at the same time.

Do you think this should be a game of "You bring all of your friends, and I bring all of my friends, and then let's fight" ? Can't we just choose the tags based on the facts?

I know what a tunnel is, and what is not. I have been surveying natural and artificial caves for 13 years, and I'm officially responsible for man-made underground facilities at the region's cave club. To make sure, I asked a club mate who has been involved in tunnel construction planning, and he confirmed that this is not a tunnel. I can forward you his mail. It would be easy for me to outnumber Negreheb and his friends by bringing some of the 500 members of our club, but again, that would be ridiculous. And frankly speaking, my club mates wouldn't love to waste their time on such a needless debate. Most of them are hard-working people who have better things to do.
Kevin Kofler (2023-07-08 05:47:53+00:00): Replying to your 4 paragraphs one by one:

1. If a DWG member tells you that something is a "golden rule", you should accept the friendly advice instead of trying to argue over it. The DWG are the ones who will ultimately have to make the call whether your edits are constructive or not, so you ought to listen to them.

2. SomeoneElse's point was that you should open a new thread in the forum if you want to continue arguing, instead of doing it here. Exactly so that you get feedback from more community members. That said, the forum is not the only place where community discussion happens. Your changes were discussed on #osm-at IRC/Matrix, which is why several people found them. We were not personally contacted by Negreheb or anybody else, that is what IRC/Matrix is for. And the channel that was used is an official discussion venue for OSM in Austria.

3. We are not Negreheb's or whoever's "friends" (see above), but community members from #osm-at IRC/Matrix. And the facts are that this underground rainwater canal (I would not call it a "sewer" since it does not go into the sewage system, but directly into the Liesing brook) is underground and as such needs a tag that specifies that.

4. What a "tunnel" is for you, or even for cave explorers in general, is not relevant here. For OSM, what matters is the definition of the tunnel=culvert OSM tag: https://wiki.openstreetmap.org/wiki/Tag:tunnel%3Dculvert which states it is "a device used to channel water" and "for a stream/drain/ditch passing under a road". In other words, this tag is intended exactly for the kind of artificial underground canal we have here, according to your own description. Hence, it is not constructive to repeatedly delete this accurate tag.
Kevin Kofler (2023-07-08 05:53:07+00:00): Since this is around 600m long, you can argue that it should be tunnel=flooded ("an artificial structure intended to channel water on a significant distance" "(over 100 meters)" – see https://wiki.openstreetmap.org/wiki/Tag:tunnel%3Dflooded ) rather than tunnel=culvert, and I would be fine with that too, but what is clear is that this needs SOME tunnel=* tag because it runs underground.
fkv (2023-07-08 06:12:30+00:00): tunnel=* neither means that an object is underground, nor do all underground objects need a tunnel=* tag. location=underground exists for that purpose, and/or layer<0 (which is already set). Apart from that, I can only repeat my request to all quarrelers to go there and see what it looks like before you steal my time.
Woazboat (2023-07-08 10:58:18+00:00): If you need an explicit written sentence on the wiki to tell you that OSM is a community project then you probably need to work on your understanding how OSM works. You aren't mapping alone in a green field and need to work in collaboration with the (local) community. 

Your definition of what a 'tunnel' is and isn't has no bearing on what the `tunnel=*` tag means and is used for in OSM. You need to work with established OSM definitions and not try to single-handedly make OSM fit your world view.

In OSM, the `tunnel=*` tag is used for a wide variety of things that are 'artificial'/'man made' passages for vehicles, people, cables/infrastructure, water, etc... to pass through something else like a mountain, soil or even buildings.

Whether it is underground or not is independent of the fact that it is a 'tunnel'.
The `layer=*` tag also only specifies the relative height of overlapping features and similarly has no influence on whether something is a tunnel or not. It also does not specify that something is located underground.

Of course most tunnels (that aren't `tunnel=building_passage/avalanche_protector`) are indeed underground and that should probably be assumed as the default so that we don't need to add `location=underground` to all of them. For the exceptions that aren't, `location=overground` should be added instead.
From that perspective, adding a `tunnel=*` tag _does_ strongly imply that it is underground, even if it does not explicitly specify it. Tagging `location=underground` in addition would also be correct (even if possibly slightly redundant).
Kevin Kofler (2023-07-08 11:28:50+00:00): > Apart from that, I can only repeat my request to all quarrelers to go there and see what it looks like before you steal my time.

Why should I waste my time going there? Seeing the object is not going to change my opinion that this needs a tunnel=* tag.

The issue is not that we do not know what this object looks like, but that we fundamentally disagree with your narrow view of what deserves a tunnel=* tag.

And layer=* by itself is not sufficient to describe something as being underground or a tunnel. It only describes its altitude relative to the other layers (and even there, only the ordering and not the precise altitude). It is a hint to 2D renderers in which order to draw things and allows 3D or multilayer renderers to separate the layers. It is also a hint to routers because it implies a turn restriction on roads crossing at different layers (as cars and bicycles cannot jump up or down). But it says nothing about whether the layer=-1 object is a tunnel, an open ditch, or just located in a dell.
fkv (2023-07-08 11:44:38+00:00): @Woazboat Yes, it's a community project of 500000 mappers and not of your gang consisting of 3-or-so persons. One of them has already proven how much he ignores community decisions by changing the tagging of Begegnungszonen against a community voting in the Talk-AT mailing list. And none of you is a local mapper in the sense that you've ever been there. Out of those who have been there, there is a 100% agreement rate that this is not a tunnel.

You say that tunnel=* is used for passages that pass through something else, but this sewer doesn't pass through anything. As I have mentioned numerous times, it has an entrance on one end only. That's a difference to the discussion mentioned by Kuhni. He pointed out that there is another entrance (where the Knotzenbach goes underground). That's why I left his tunnel=* tag in place, even though he allowed me to remove it. Another difference is that he *is* a local mapper who contributes, whereas the people involved in this edit war with me are not.
Kevin Kofler (2023-07-08 12:23:23+00:00): The community voting you mention was overturned by a more recent voting in the forum.
Kevin Kofler (2023-07-08 12:25:12+00:00): And water necessarily enters somewhere and exits somewhere else, whether you can see the entrance/exit or not. That is just basic physics.
Kevin Kofler (2023-07-08 12:35:53+00:00): @SomeoneElse: I hope you can see from the above discussion that it is impossible to reason with fkv and that the only thing that will work is sanctions.
SomeoneElse (2023-07-08 22:36:57+00:00): (answering some of the questions above)

> Are you sure you got your forum link right?  
Yes, I deliberately linked to the Austrian forum.  The international tagging forum is https://community.openstreetmap.org/c/help-and-support/tagging/71 ; I suspect you'd receive even more pushback there.

What you seem to be saying is that it is an "underground drain that is somehow not a tunnel".  Obviously I've never been to the location in question so can't add my own thoughts as to how to tag this particular example, but tunnel tags are regularly used with the underground portions of drains and ditches.
fkv (2023-07-09 00:15:12+00:00): Yes, if they have an entrance on each end. A tunnel=* tag signals the renderer to render an underground passage with an entrance on each side so viewers know they can get out at the other end. It's dangerous to add tunnel=* tags to objects that don't have that other entrance, as it would mislead viewers into thinking they can get out at the other end when they actually can't. They get deeper and deeper into it and potentially get stuck. Note that this particular sewer gets tighter the deeper you crawl into it. Even if you don't get stuck, you may lose orientation. There's no GPS inside and no mobile phone reception, even if you get close to one of the manholes. The danger is real, and armchair mappers have no idea about it. Do you want to be responsible when a serious incident happens? In the best case, OSM would only be in the news for causing a rescue operation. In the worst case, there would be an indictment for manslaughter, and the culprit wouldn't be me, that's for sure. Even if no incident occurs, the risk creation alone is already a violation of Austrian law. The criminal offence is called Gemeingefährdung (public endangerment), § 177 StGB (or now that you know about it, it would be intentional: § 176 StGB – the minimum jail term is 1 year).
Kevin Kofler (2023-07-09 05:57:49+00:00): Neither tunnel=culvert nor tunnel=flooded implies that you can walk through the object, that is your major misunderstanding. I would say that "flooded" even pretty much implies that you can NOT walk through the object because it is flooded with water. But even with "culvert", that follows from the tagging as a waterway.

The water surely enters somewhere and exits somewhere, but nothing in the tunnel tag implies that those entrances are usable by humans.

People doing dangerous things due to OSM tagging is an issue we have in the mountains with "footways" that are really alpine climbing paths. I have never heard of it ever having been an issue with tunneled water canals, at least here in Austria.
Kevin Kofler (2023-07-09 06:02:41+00:00): PS: And the current tagging is much more misleading because it makes it look like the canal is not covered (and that is also how the renderers will render it, but even interpreting the tags manually will give this false impression).
Luzandro (2023-07-09 06:16:41+00:00): > "footways" that are really alpine climbing paths

There are people, who consider climbing routes of grade 7 to be highway=path

https://www.openstreetmap.org/note/3053909
SomeoneElse (2023-07-09 08:13:32+00:00): Re:
> Yes, if they have an entrance on each end. A tunnel=* tag signals the renderer to render an underground passage with an entrance on each side so viewers know they can get out at the other end. 
You _really_ do need to discuss your interpretation of "what a tunnel is" NS "what other features it implies" more widely.
KaiRo (2023-07-09 12:12:49+00:00): fkv, it's great to have experts like you in this community, this is one thing that makes OSM so special. Now, this case looks to me like it is a simple misunderstanding. OSM tags are very often used for a much broader calls of objects than the expert or common definitions of those names. This is to make it easier for applications building on the database, needing to support fewer classifications (and there are already a ton). What experts (or even "normal" people) call a "tunnel" is something different than what the tunnel=* tag in OSM is used for. There is overlap of course, but the OSM tag goes farther than the expert or common definition, and we tag things as "tunnel=*" that are just "similar" to what a "tunnel" usually is. Also, having that tag on it doesn't mean in any way that people can or should enter it. It's merely to say that this way is "housed" in some way and going underneath the ground or large other objects (and not just covered with a roof or similar, which would be "covered"). In this concrete case, if this waterway doesn't have this tag, it would have to be visible on the surface, and I think we can all agree that it isn't. So, the only two options are to not have it exist at all in OSM or to have it marked with the "tunnel=*" tagging, which may not fit the expert definition but it "good enough" for OSM. And yes, any other underground drainage or sewer should have that tagging as well, if it's geographically relevant enough to be in the OSM data set at all.
fkv (2023-07-10 19:23:54+00:00): @SomeoneElse: tunnel=* is defined in the wiki as an "underground passageway". As a native English speaker, would you say that a cul de sac is a passageway? Is it a passage if all you can do is return to the starting point?

If the anwer is yes to both questions, I can try to write a clarification proposal (similar to what I've done for natural=cliff), but it will take me at least a week because I will be handicapped from chemotherapy.

@KaiRo: Why would it be visible on the surface if layer<0 or location=underground is set? Are you talking about Carto rendering? Maybe it's just a Carto bug? Or location=underground (which is currently not set) fixes Carto rendering? If it's not about rendering, but just about tagging, then I'm curious if you want to make tunnel=* compulsory on all linear underground objects, or if there are any exceptions. The next question would be whether you wish to deprecate location=underground in favor of tunnel=*.
SomeoneElse (2023-07-10 19:38:55+00:00): > As a native English speaker, would you say that a cul de sac is a passageway? Is it a passage if all you can do is return to the starting point?

Yes, "tunnel" can be used for features like that.  No one would think that https://en.wikipedia.org/wiki/Williamson_Tunnels are not tunnels because there is no exit at one end for some of them.

Rather than "writing a clarification proposal" I'd again suggest (as I mentioned before) just discussing it with other users on the forum.

I have to say, if this is a sewer / drain that drains into the stream to the north, surely there's some way for water (or, er, "other fluids") to get into it in the first place?  Presumably some sort of pipework?
Woazboat (2023-07-10 19:55:45+00:00): As an additional data point: Mine tunnels also (often) only have one entrance, are not meant for transportation from one end/exit to the other, and are also tagged with `tunnel=*`.
https://www.openstreetmap.org/way/227946737

Note that 'tunnel=*` does not necessarily mean it's for humans in the first place. (e.g. `tunnel=culvert`)

> make tunnel=* compulsory on all linear underground objects

If they are artificially 'housed'/'eingefasst' then yes. Not if it's a natural cave.
Woazboat (2023-07-10 20:05:01+00:00): I think the wiki page for `location=*` provides a reasonable guideline for when to use the `tunnel=*` key.

https://wiki.openstreetmap.org/wiki/Key:location

> "For features which are contained within a _self-supporting_ tunnel (...) use `tunnel=*` (...)"

This distinction is quite reasonable I think. If a cable is simply buried in the ground without anything around it it would just be tagged with `location=underground` without a `tunnel=*` tag.