[Tagging] Micro- and macromapping with area=*

Daniel Koć daniel at xn--ko-wla.pl
Mon Mar 30 15:02:29 UTC 2015

Lately I was trying to rethink our general tagging schemes and came up 
with the impression that areas half-designed part of OSM tagging system.

IMO we have 2 problems with it: small one in microscale and a big one in 
macroscale, but most probably we can deal with them separately.


In microscale we have some common uses of area=yes tag as area hint, 
like with highway=footway, highway=pedestrian or highway=service. But I 
think we also need some other like (a) highway=cycleway + area=yes or 
(b) highway=crossing + area=yes (both are quite easy to extend) and more 
complicated, but highly needed (c) street area scheme like in 
http://wiki.openstreetmap.org/wiki/Proposed_features/Street_area .

We won't see the issue just looking at the taginfo usage statistics:


but it's easy to understand there's something wrong with having some 
popular area types being tagged and rendered as such, while some other 
are still considered just a point or a line. And it's not the future, 
it's already here at z19 (z18 is still rather fine) - for example some 
streets can be even 4 times wider than on default rendering (see the 
holes between footways and the streets at 
http://www.openstreetmap.org/#map=19/52.23171/21.02082 )!


Macroscale is harder, because general hierarchy of tags is treated as 
given and I think we need to fix this hierarchy a bit. The problem is 
best visible when compared to buildings and I already wrote about it on 
Talk list, so let me quote relevant parts:

"That's what we have now (forgetting the buildings functions issue for a

amenity=school & building=school
landuse=religious & building=church
landuse=industrial/man_made=works & building=industrial (?)

and I see the pattern like this:

area=school & building=school
area=religious & building=church
area=industrial/works & building=works

Just "area" instead of "amenity/landuse/man_made/..." hell - isn't it
easier and more elegant?"

"You can spot a building and you know what the rules are:

1. The key will be always "building" - not anything else (like "house" 
or "architecture").
2. If you don't know anything more about it, "yes" is safe, general 
value you can always choose (and if you know the form, you are welcome 
to choose something specific).

What if we could have the same level of clearness for areas? For example 
natural=wood vs landuse=forest - you see the area covered with trees 

1. You are not sure what the key should be (is it maintained or not?).
2. You have no safe general value, because "wood" implies "natural" key
- but again: you may not know if it's really not maintained.

"Area=trees" might be the kind of close analogy to "building=yes" in 
such cases. BTW: it's still available (
http://taginfo.openstreetmap.org/keys/area#values ) and such use isn't 
even disallowed in the light of our current documentation ( 
http://wiki.openstreetmap.org/wiki/Key:area )."

[ https://lists.openstreetmap.org/pipermail/talk/2015-March/072375.html 


What do you think about both micro- and macroscale changes in scope of 

Piaseczno Miasto Wąskotorowe

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