[OSM-talk] Proliferation of path vs. footway
Morten Kjeldgaard
mok at bioxray.au.dk
Tue Aug 11 12:41:56 BST 2009
Hi,
It seems to me that tags have proliferated because as time has gone
by, people have invented more-and-more uses for OSM -- and that is good!
However, it is a problem because mappers are trying to accomplish very
different things from the same set of tags. Here is a set of distinct
problems I can think of off the top of my head:
* Classical map features. Cities, roads, forests, ferrylines. Where
does a road/path lead? How do I get from A to B? Bridges, railway
crossings, etc.
* Legal rights. Is this road accessible to the public? Am I allowed
to drive a car here? Bicycle? Horse?
* Administrative: Who owns this road/area and who takes care of it?
* Terrain. Is this road suited for bike-racing? Mountain bikes?
4WDs? Is it steep? How steep?
* Surface: paved, gravel, grass sand?
* Environmental: Chemical/Radioactive pollution?
* Security: where is there a phone, hospital, mountain shelter? Wild
animals?
So it appears there is also an evolutiont in tags to encompass more
and more of these distinct (and useful!) pieces of information, but
unfortunately tags are being added in a ad-hoc manner to solve
particular problems without concerns of maintaining a reasonable
namespace. The addr: namespace is a good example of how a set of
complicated tags can be grouped so they don't interfere with other
requirements.
As time goes by, who knows what OSM will be used for? Perhaps the
public works of some city decides to put their water and electricity
lines on the map? Perhaps some agricultural agency wants to use OSM
for soil characteristics?
The highway=footway is IMHO an alias for the more complex highway=path
foot=yes surface=paved etc. construction. I think aliases are
perfectly legitimate constructs when dealing with very common
situations, and furthermore, much easier for newbies to remember and
deal with.
Perhaps it would be constructive to discuss the tagging structure
considering the various purposes tags have, and in line with the good
example set by the addr: namespace. For example, national OSM teams
might have access to their own name spaces, for example fr: (France)
de: (Germany) etc.; this would eliminate discussions of the differing
interpretations of certain tags that now occupy a lot of the bandwith
of this ML.
Cheers,
Morten
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