Passable vs impassable scrub (or heath)

Claudio_Tam · 2022-11-07T09:36:01.269Z

Hello!
I usually tag remote areas, which are often scrubs or heaths. It would be nice to tag which areas are passable by foot and which ones are unpassable. I’m not referring to a specific path, but to the entire area which could be passable or unpassable.
As an example, there is sometimes a big area of unpassable scrub, right next to a big area of easily passable scrub. It would be really helpful for foot navigation to tell apart passable and impassable areas. How can I tag this difference on the map?

dcapillae · 2022-11-07T11:31:18.538Z

See Key:obstacle on the wiki:

The goal of this tag is to mark obstacles which are not derived from the properties of the road (surface, material, width, etc.) but from its environment or local properties. […] This tag can be used in a navigation application to avoid areas.

It may not be exactly what you’re looking for, but it’s the closest I could find.

Matija_Nalis · 2022-11-07T20:19:31.717Z

You could add Tag:foot=no - OpenStreetMap Wiki on unpassable ones…

Foot routers however probably won’t use any tags on such natural=scrub areas for navigation anyway. You might decide manually if they show you extra tags, but that is not very useful for automatic navigation.

If they are useful ways to traverse them (and more man-made more convenient alternatives unavailable closeby), you should probably pick most likely ones and create separate ways for them, so routers could use them:

highway=path
informal=yes
surface=ground (or grass or whatever)
sac_scale=hiking (or above)
smoothness=xxxx
trail_visibility=xxxx

Map_HeRo · 2022-11-07T20:20:56.408Z

How would you want to tag obstacle for an area? natural=scrub + obstacle=vegetation? Does not make much sense to me.

There is no tag for the passability of an area as far as I know and it is hard to imagine how one should be working … within an “impassable” scrub there might be gaps to pass when taking a close look whereas a scrubby area which might be passable in early spring could well become impassable in late summer when thorny scrub has grown all over the place.

Matija_Nalis:

If they are useful ways to traverse them (and more man-made more convenient alternatives unavailable closeby), you should probably pick most likely ones and create separate ways for them, so routers could use them:

I understood @Claudio_Tam to talk about wayless areas. Would it make sense to “create” trails there which are not existing OTG? When looking at an area of lets say 1km2: From where to where create these trails…??.. vertically…?.. horizontally …?.. diagonally …?

Imho we should restrict routing tags to existing ways and leave areas without ways for the few adventurous who are willing and able to find their own way.

dcapillae · 2022-11-07T20:59:02.341Z

Map_HeRo:

How would you want to tag obstacle for an area?

I have proposed no such thing if you notice.

Map_HeRo · 2022-11-07T21:14:31.431Z

No worries mate … I did not want to express you proposed that, my question was of general nature how to use the tag obstacle (thrown in by your post) on an area.

SomeoneElse · 2022-11-07T21:30:44.739Z

While certainly not a perfect answer to the question you’re asking, perhaps smoothness comes closest. Access tags certainly aren’t an option - apart from “wheelchair”, they show legal access rules rather than physical suitability.

Matija_Nalis · 2022-11-07T21:35:24.330Z

Access tags certainly aren’t an option - apart from “wheelchair”, they show legal access rules rather than physical suitability.

It seems to depend… wiki https://wiki.openstreetmap.org/wiki/Tag:foot=no says Access on foot or by pedestrians is prohibited or impossible, where I would take that impossible to mean a physical restriction, not legal one (like prohibited is).

SomeoneElse · 2022-11-07T23:36:00.044Z

Matija_Nalis:

It seems to depend

No, that’s just wikibollocks. That page used to be a redirect, and the page it redirected to is still correct. The page was edited and the “impossible” text was only added only in March 2021.

To be clear - I’m sure that the person making the edit thought that what they were doing was “correct” or even “uncontroversial”, and was doing the wrong thing for the right reason.
However, there are lots of pages in the wiki - unfortunately it isn’t feasible to monitor them all and it is easy for someone to create a new page that disagrees with what most people think, and go unnoticed.

Edit: I said “prohibited” not “impossible” previously, in error (as mentioned below). I’ve now corrected it.

Hungerburg · 2022-11-08T11:31:12.628Z

I think you meant, “impossible was only added late”? At least that’s what the change to the wiki article implies.

SomeoneElse · 2022-11-08T11:44:20.910Z

Yes - my mistake in the previous reply!

Hungerburg · 2022-11-09T21:26:27.111Z

From what is mapped scrub in the area of my local knowledge, it is a sure sign of the area being close to impassable, that is, it will make you sweat like a pig (so we say here) and reduce pace to a crawl. From what is mapped heath, such cannot be said for certainty. Pace depends mostly on your interest in wildlife studies

fortchagos · 2022-11-09T23:51:16.756Z

Some thoughts …

The definition of passible and impassible for these area?
Since the desire is to define this on a natural area, how will it be maintained/updated over the years as the vegetation grows and dies or removed by cutting or fire - particularly in remote areas? It would seem such tagging has a temporal quality to it. Imagine tagging a farm field with the crop (crop=corn) just to have a different crop planted after harvest (crop=wheat)?