Proposal talk:Covered

• denote that an object is covered by another object where the use of layers or tunnel (eg a footway, on the ground but under a building) is inappropriate.. FrViPofm 22:52, 3 November 2009 (UTC)

As stands, I think this is too general. Using the same tag to represent that a bridge is a covered bridge and that a power line is buried is overkill. Unfortunately, unless the definition gets tightened, I have to oppose. Anthony 15:53, 4 November 2009 (UTC)

I have no problem with this being broken into three proposals, "covered", "buried" and "submerged" to cover the same functionality, if that is the general consensus. However, I personally prefer the KISS approach. --Turbodog 22:26, 4 November 2009 (UTC)

Partial concession on this issue. See last paragraph of response to Ed Avis. --Turbodog (Randy) 18:42, 5 November 2009 (UTC)

not sufficient

See levels for a method to map 3D objects. --Lulu-Ann 12:24, 4 November 2009 (UTC)

As stated in the referenced levels, "A level is a floor in a building". "Covered" is intended to tag items that are exterior to the building, although they may pass through (such as a pseudo tunnel) or under (such as a portico) a portion of the building confines. It seems to me one would have to create a complex relation for the building, which included a way which was not truly a part of the building, just to show a simple covered passage. While that might be doable, it seems like overkill, and would add excessive and unnecessary computation requirements to, for example, a router that is attempting to create an outside pedestrian route with minimum exposure to the elements. If it were raining and I was waiting for someone in the portico of a building, talking to them on a cell phone, I would not say "I'm on the ground floor of the building", I would say "I'm outside, at the front entrance" (optionally adding, "under the portico"). -- Turbodog 20:21, 4 November 2009 (UTC)

Why is this needed?

I've read the description but I don't understand why layer is insufficient for the examples given.

If a building has a road passing through the middle then at layer 0 surely you should map the road and the two halves of the building on either side? Or, indeed, just make it a convention that roads passing through buildings on the map are covered by higher floors of the building - this seems to be the convention already used on the map, and doesn't seem to require a new tag. Tagging whether a power line is buried or in a trench seems like a good idea, but wouldn't buried=yes/no suffice for that? I suppose the question I'd ask is when would a road passing through a building ever *not* be covered? -- Ed Avis <eda@waniasset.com> 09:39, 5 November 2009 (UTC)

If you must depend on layering, then you must map the way (road, path, etc.), the two building halves, and the upper floors as a separate layer, and then create a relation between them. This is fine if you want to get into the complexity of 3D building mapping. But, I believe that those whose primary purpose is to map ways for routing purposes will not want to get into that complexity, just to show that a characteristic of the way is that it is covered. I know I don't. I'm perfectly happy to leave the whole 3D building rendering thing to others at this point. There are many more basic mapping issues to be addressed in my city.

Do you have a reference to the convention of roads being assumed as under buildings? I'm not aware of one, and it is well known that this is not the way they are currently rendered, see http://www.openstreetmap.org/?lat=32.679882&lon=-97.394399&zoom=18 and http://www.openstreetmap.org/?lat=32.6952360570431&lon=-97.3609766364098&zoom=18 as examples. I suppose that COULD be established as a convention, but it clearly is not at this time. As far as when is a way passing "through" a building not covered by higher floors, the answer is when the way is on top of the building, as service lanes in a roof parking lot.

- Good points, I had not considered the case of lanes on top of a building. If this proposal goes ahead then existing roads through buildings will need checking and tagging with covered=yes or covered=no (I think the latter will be more common). That's fine, I'm happy to support this proposal. -- Ed Avis <eda@waniasset.com> 12:08, 6 November 2009 (UTC)

I think covered=no as the default should be adequate for situations where that is the case, and no property would need to be added.--turbodog 05:29, 7 November 2009 (UTC)

Regarding buried/submerged vs. covered. I have thought of situations where the two should be distinguished, i.e., a way (power line, water main, etc.) that is buried in the ground, versus the same way in a concrete trench with removable concrete or metal plates covering it. It would definitely be advantageous to key those differently due to the availability, one by excavation only, the other by removing the plates. I'll modify the feature page to indicate that a way that is "covered" but does not penetrate a structure edge, implies that the cover is removable. This would also apply to storm drains along highways, as I have seen them in other countries, besides the US, in particular, Japan comes to mind. I'll add a photo reference later. Likewise I'll remove the submerged reference and leave that to another proposal. --Turbodog (Randy) 18:37, 5 November 2009 (UTC)

porticos and tunnels through buildings

I'd keep using tunnel=yes for tunnels through buildings. No need to split the building, or add any layers: make the road share a node with each wall and make the section through the building a tunnel. I'd say that even the right hand tunnel in the given example http://www.bahnfotokiste.de/s_bahn/blankenese/blankenese_6.html is a tunnel through that building. Only when the building looks like a "bridge" over the road below, I'd consider splitting the building further away from the road (where the walls are, naturally)) and making the central section layer=1 + bridge=yes... the example picture of Brückenrasthaus could be an example of that.

In your last example above, layer=1 on the overpassing structure should be sufficient; under most circumstances there should be no need for "bridge". The alternate, if you don't want to break the building into pieces, and then ues a relation to put it back together again would be to use covered=yes on the road. That would depend on the circumstances - how you understand the building, and what you are trying to accomplish. -- --turbodog 05:57, 7 November 2009 (UTC)

Only for features shorter than their width, or open on multiple sides, such as the mountain road example at http://de.wikipedia.org/wiki/Datei:Galeriestra%C3%9Fe_cropped.jpg would be misleading to tag as a tunnel, so covered=yes would be a good attribute for such cases. As for the covered bridge example, I'm content with current practice of tagging such as bridge=yes + tunnel=yes. I've personally drawn some significant porticos as highway=pedestrian + area=yes + tunnel=yes and sharing nodes with the building on all open sides, but will switch them from tunnel to covered. IMO if there are floors above the portico, the building extends to the outline of the roof and with the proposed tag it could be drawn respectively. In the end it's then just a matter of agreeing on whether to split the building into two areas, the "above portico" part and the part "touching ground". Then again, there are some significant/large canopies/extended roofs (as separate ways, sharing some nodes with the building itself and tagged man_made=canopy), under which the walkable area would also be with covered=yes. Alv 09:29, 6 November 2009 (UTC)

To me, tagging an item as both a bridge and a tunnel seems contradictory - personal opinion - but something I could live with. I know others have stronger feelings about it. -- --turbodog 05:57, 7 November 2009 (UTC)

Random comments

• Would "undecover" work better? "Undercover parking" sounds better than "covered parking".
  • I guess it depends on where you are from. "Covered parking" is a common term here. It can describe anything from underground parking to a multi-level parking garage, to a corrugated roof over an open parking place.
• Does this include "indoors"? Ie, a mall, a garage, a warehouse...
  • Yes, in some cases. Remember that it is primarily for use where layers are ambiguous or contradictory. A good example would be a service road running through a warehouse. They are both constructed on the ground at the same elevation, and the warehouse is contiguous; not walls with a separate roof perched on top (unless you want to get into 3D mapping). It doesn't make sense to me to "trench" the road at layer=-1 nor to "suspend" the building at layer=+1 to indicate that the road is covered by the warehouse rather than going over it (as a roof parking area might go).
• The "reservoir_covered" tag does sound dubious enough to be better as "covered=yes". I can't really picture a covered reservoir...it might be a stretch to use the same tag for this, as well as for roads that happen to be under cover...Stevage 06:59, 4 December 2009 (UTC)
  • We use the same property on different types of ways and areas all the time. The most common one is probably using "bridge=yes" for both highways and railways. The use of "tunnel" can be found related to highways, railways, and waterways. Why not "covered=yes" for different types of ways and areas? There are numerous examples of covered reservoirs (else why the older "reservoir_covered"?). The Kelly Tarleton Aquarium cited in the text was built in an abandoned underground reservoir, that was excavated into the side of a hill.--turbodog 20:01, 4 December 2009 (UTC)