[Tagging] highway=footway - Advanced definition: Distinction footway vs path

[Richard]

On Tue, Aug 04, 2015 at 05:41:52PM +0200, Michael Reichert wrote:
> Hi Richard,
> 
> Am 2015-08-04 um 16:59 schrieb Richard:
> > On Sun, Aug 02, 2015 at 11:43:21PM +0200, Michael Reichert wrote:
> >> I fully oppose highway=footpath. This is not backward-compatible and
> >> will therefore break almost all applications which use OSM data. It
> >> conflicts with existing, heavily used tagging. 
> > 
> > quite the opposite. It won't break anything. It will be ignored for some
> > time untill data consumers learn about th new tag.
> 
> Every data user who does not support highway=footpath will loose all
> paths have highway=footpath because he expect them as highway=footway or
> highway=path. That's what I call backward-incompatible.

sure, but there are no such paths right now so nothing will be lost.
People who create them will have to live with it that they won't show up
on mapnik for some time or mabye never will. highway=via_ferrata isn't
rendered on mapnik, so what? Footpaths naturally aren't the main scope
of mapnik and there are several specialised hiking/outdoor maps which
are much better at this.

Redefining existing tags is what causes true breakage. In 2008 highway=path
was approved saying 
   "The default access restriction of highway=path is open 
    to all non-motorized vehicles, but emergency vehicles are allowed. "
Some years later, Feb 15 2015 the page was changed without vote and discussion 
to claim that : 
   "The default access restrictions of paths varies from country, see 
    OSM_tags_for_routing/Access-Restrictions"
- with the net result that all highway=path (s) previously mapped in Austria 
were retroactively changed to imply "bicycle=no" unless explicitly tagged 
otherwise.
  http://wiki.openstreetmap.org/w/index.php?title=Tag:highway%3Dpath&diff=1141261&oldid=1118909

Changning default restrictions of well known and widely used tags is the 
way to hell.

Richard