[Talk-GB] Advice please: Goat tracks in mountain areas

[Philip Barnes]

On Sat, 2022-02-05 at 15:04 +0000, David Woolley wrote:
> On 05/02/2022 14:26, Gruff Owen wrote:
> > 
> > It has been tagged as:
> > bicycle:no
> > highway:path
> > horse:no
> > 
> 
> What would initially concern me is that bicycle=no and horse=no
> probably 
> represent the mapper's view of its suitability, and are therefore
> very 
> subjective, which is wrong.
> 
> Not mapping it would be wrong.  The correct way is to provide 
> attributes, e.g tracktype=Grade 5; surface=ground; width=70cm; 
> smoothness=horrible; sac_scale=difficult_mountain_hiking, that allow
> a 
> router to make its own judgements (although some of these could also
> be 
> considered too subjective).  I'm not sure though, to what extent
> routers 
> actually look for such contraindications, but there is a principle
> that 
> you do not tag for the renderer, which means it is the router's job
> to 
> assess suitability and one must not try to influence it by
> misdescriptions.
> 
> Pyg Trail, to which this path is attached, is classified as 
> sac_scale=mountain_hiking, in OSM, which is the second least onerous.
> The description for sac_scale says that paper maps often do not
> include 
> paths with the most onerous values.
> 
> Total omission doesn't work, if the feature is visible, because
> people 
> will, eventually, remap it.
> 
This sounds a good approach, although in my experience goat or sheep
tracks end up with a width more like a sunken 10cm path on a steep
slope where it becomes difficult to get one boot in front of the other.

Could be worth a changeset comment pointing out the problems with
mapping this type of path without careful tagging and determine
motivation/sources used.

Phil (trigpoint)