Warn if bridge=* && tunnel=*

[RicoZ]

Apparently there are 3006 cases worldwide.

Example - ​https://www.openstreetmap.org/way/164721951 has tunnel=culvert + bridge=yes.

[Klumbumbus]

While working on #11837 I noticed that there are a lot of cases with tunnel=* and bridge=* which are valid (overground tunnels or underground bridges). So a warning would produce a lot of false positives. I'm pretty sure that even your linked example is valid. This canal is covered on long passages, and in this case on a bridge.

[RicoZ]

Imho anything that looks like a tunnel but is on a bridge is a kind of a covered bridge. We have bridge=covered and bridge=* + covered=yes to for this cases.

The wikipage for tunnel says in the first sentence "tunnel=* is used for roads, railway line, canals etc that run underground (in tunnel). " (there is the exception tunnel=building_passage)

Underground bridges could exist in subway stations and similar. However that does not mean that the same way should be tagged tunnel & bridge at the same time. If it is an underground building it could be level+bridge (where I consider the bridge as somewhat optional as building levels are in concept similar to bridge).

If there is a bridge in a tunnel than there are multiple ways in that tunnel and as long as there is no equivalent to man_made=bridge there is no way to model it correctly. For the time being location=underground + bridge=yes might be slightly better.

In practice I have looked at bridge & tunnel & layer=-1..-3 and soon gave up seeing very few that looked legitimate, mostly tunnel=building_passage or with either location/level/indoor

[Klumbumbus]

Imho anything that looks like a tunnel but is on a bridge is a kind of a covered bridge. We have bridge=covered and bridge=* + covered=yes to for this cases.

covered=* is usually used for cases, where atleast one side is open. Ok, for bridges this is maybe a bit less strikt, but for example in this case ​way/207832488 I cannot really say, that this is tagged absolutely wrong.

The wikipage for tunnel says in the first sentence "tunnel=* is used for roads, railway line, canals etc that run underground (in tunnel). " (there is the exception tunnel=building_passage)

Underground bridges could exist in subway stations and similar. However that does not mean that the same way should be tagged tunnel & bridge at the same time. If it is an underground building it could be level+bridge (where I consider the bridge as somewhat optional as building levels are in concept similar to bridge).

If there is a bridge in a tunnel than there are multiple ways in that tunnel and as long as there is no equivalent to man_made=bridge there is no way to model it correctly. For the time being location=underground + bridge=yes might be slightly better.

bridge/tunnel=yes does not mean that the way IS a bridge/tunnel, but that the highway/waterway/railway/... runs over/through a bridge/tunnel. So if a railway=* runs over a bridge in a (big) tunnel (with more railways in the same tunnel) then both bridge=yes and tunnel=yes are correct at the same time.