On Wed, 27 Jan 2016 09:53:14 +1100 Warin <61sundow...@gmail.com> wrote:
> On 27/01/2016 8:50 AM, Clifford Snow wrote: > > > > On Tue, Jan 26, 2016 at 1:14 PM, Warin <61sundow...@gmail.com > > <mailto:61sundow...@gmail.com>> wrote: > > > > layer=-1 to me says this is below natural ground level. And here > > that is not the case - the road is above natural ground level > > and that should be tagged layer=1 .. to be absolutely technically > > correct. > > > > But many use the layer=-1 on culverts as a convenience of less > > work. > > > > tunnel=building_passage > > > > I am not understanding where that tag would be applied. What > > would be > > tagged this way? > > > > > > The convention it to tag what is inside the tunnel. Similar to a > > bridge where what is on the bridge carries the tag. > > > > > > According to the wiki: > > > > Layer provides absolutely no information about relative or > > absolute height difference of objects which do not immediately > > cross or overlap. A change in layer should not be used to > > indicate a change in elevation. A bridge is at layer 1 even if it > > is only several feet above sea level while the peak of Mount > > Everest is at layer 0 even though it is 8848 meters above sea level. > > > > Negative values do not imply that object is underground, use > > location > > <https://wiki.openstreetmap.org/wiki/Key:location>=underground > > > > <https://wiki.openstreetmap.org/w/index.php?title=Tag:location%3Dunderground&action=edit&redlink=1> > > for this purpose. > > > > Since it is a culvert, going under a road, I use layer=-1. If you > > tag it layer=1, then you are saying the stream is above the road. > > Err no. > I would prefer to tag the road at layer=1 as that is elevated > compared to what naturally existed before. Note this is a > 'preference'. I too take the path of less work compared to being > absolutely technically correct. > > > Which might be correct in some instances, but looking at the > > picture, it looks like it goes under the road. If you call the slab > > of concrete a bridge, then layer=1 would be correct. > > > > Clifford > > > > > I think the wiki is deceptive in claim level=0 does not imply > anything. I think it implies the"local ground level" level=0 means that given object is at ground floor of building. ( see https://wiki.openstreetmap.org/wiki/Key:level ). layer=0 (or better and more common - lack of layer tag) means that it is above intersecting objects tagged with layer=-1, layer=-2 etc and below intersecting objects tagged with layer=1, layer=2 etc. location=underground, location=overground etc give information about position relative to the ground. _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
