[OSM-dev] Overlapping polygons - verboten or not?

[M∡rtin Koppenhoefer]

2011/4/20 Patrick Kilian <osm at petschge.de>:
> Overlapping polygons are definitly ok. A closed way with building=yes on
> top of a landuse=residential area is perfectly ok and very common.


+1


> The rule is "don't create overlapping polygons of the same type". So two
> landuse areas, say landuse=residential and landuse=forest, shouldn't
> overlap.


Even this might depend on the "type" / key/value. And as landuse is
not describing actual landuse (sometimes it is landcover, see
landuse=grass) this rule is IMHO not even valid for landuse. How else
would you describe a "forest" on a brownfield or greenfield? Or on a
landfill?

I'd say generally it is OK to make overlapping polygons, but some
combinations (e.g. landuse=industrial and landuse=residential, or 2
overlapping polygons both with landuse=residential) are not valid / do
not make sense.

cheers,
Martin