Should keys like trail_visibility & sac_scale etc exist, given difficulties with verification / some interesting thoughts on trail_visibility

[erutan]

A few replies to what’s been said here already.

@Carnildo

@Adamant1

I think what your talking about is illustrated well in the first image from this post. In that case the “path” is covered by some broken branches, but it’s still clear where the “trail” is because of the clearing in the trees.

No. That’s a nicely-visible trail – I’d rate it “good” or better.

I described that as good in my post, and it’s a useful example of how just relying on surface etc doesn’t replace visibility, as it is less visible than many surface=compacted trails in that thread that would clearly be described as excellent.

@Adamant1

So would I. That was kind of my point since Adam_Franco said overgrowth and revegetation affect trail visibility. At least in that image it apparently doesn’t

That’s because… the trail isn’t actually overgrown.

There’s very little vegetation on it compared to the surrounding terrain, and what vegetation is there is obviously far younger than the surroundings. It’s an abandoned trail not shown on official maps anymore with some twigs on it that gets light year round traffic.

@Adam_Franco

a fine-grained deterministic 6-point scale might not be possible, but I believe that a global consensus is reachable on some large buckets:

This makes a lot of sense to me (and mirrors some of my thoughts in the previous thread). The “mental load” model vs plodding is a very useful way of looking at it. I think the first example would only be excellent as things stand. As defined the second and third would overlap from good to intermediate, and then the last would include bad, horrible, and no.

The “can just plod along looking at their feet or chatting without wondering if they are still on “the trail” or not” and " A key distinction is that losing the path is possible for novices and there is some mental load of looking ahead for those not familiar with the path" feel pretty perfect.

The third seems harder to define clearly - it’s more of what “intermediate” should be IMO. As of now intermediate and bad are essentially the same rating (mostly visible vs sometimes invisible) but this makes sense to me.

The fourth should include trails that “come and go” it reads now that it’s essentially entirely pathless. On the other hand there’s a IMO strong case to be made for breaking these segments into a true visibility=no, and having visbilities above that separate segments, but that’s another thread I’ve been toying with making.

I think it’s ridiculous that in the current rating there’s one for a clearly visible continuous trail (excellent), one for a (nearly) continuous one with adequate visibility one (good), and then intermediate through no are just different proportions of “there isn’t a path”.

@Adam_Franco

There will certainly be some regional variation based on trail construction practices, but “is a novice likely able to follow the path easily” shouldn’t be that subjective.

I think there can be regional differences in this - a novice that is used to only gravel paths might get confused by a single track dirt trail that people used to them would consider “novice friendly” in areas that mostly have compacted single track. Minor spur trails to viewpoints and water etc complicate things a little bit in terms of “plodding along”, but there’s no real risk as they can easily backtrack a hundred feet or so so the trail and continue on.

@Adam_Franco

The trail isn’t immediately obvious or distinct from the surroundings. Even experienced hikers/mountain-bikers who don’t know the trail likely need to expend continuous watchfulness to evaluate where it goes. Crossing animal paths may be as distinct or more distinct than the path. There is a strong likelihood that novices would get lost.

This is probably mostly falling under bad and horrible.

This reminds me of some quick thoughts on the trail_visibility thread referenced earlier, though I think your take on them is more nuanced and complete.

@erutan

• excellent unambiguous continuous path which is easy to follow, even in reduced visibility
• good a continuous path which may become faint or indistinct at times, become braided, or have minor gaps with the next section visible so users may have to look around for it occasionally. It is always findable without having to hike pathlessly.
• bad a path which exists in places, but requires routefinding to find the next section at times
• no no path exists in any meaningful sense

Essentially:

excellent: a tourist which has never set foot on dirt can follow this
good: a moderately experienced trail hiker can follow this without any major issues, but might get confused at times.
bad: off-trail hiking experience or mountaineering background recommended as someone will need to read terrain and “make their own path” in between sections of it that are visible.

@brightj

Probably it should prefer whatever scale is used locally, but allow conversion to others? (In the same way that OSM uses feet and inches in the US and meters in other countries.)

That could be difficult to do programmatically - I took a stab at that in the scramble quote up in the original post in this thread and there’s some things that overlap. I hadn’t seen the summit post conversion chart, but I’d disagree with a few takes on it - I think YDS 3 to UIAA 1 is probably sandbagging UIAA, and SAC T2 should definitely still be YDS 1, as you aren’t using hands for balance.

@erutan

Class 1 YDS, SAC T1-2, Austria Blue, SWW Yellow, CAI T & E

@erutan

Class 2 YDS, SAC T3, UAII 1, Austria Red, SWW White-red-white, CAI EE

@erutan

Class 3 YDS, SAC T4-5/6?, UAII 2, Austria Black, SWW White-blue-white, BMC Grade 1, Schall Scale A, Hüssler Scale K1

There would be issues converting a YDS 3 or AWTGS 5 to SAC - would it show up as 4 or 5? Someone comfortable on T4 might not mind being on T5, but you’d’ have to pick one or another, vs some osm_scale that would by definition include that range of terrain. On the downside it’d be yet another system to learn - but could be used globally as it would map to localized systems.

@Adam_Franco

In my community many of our single-track mountain bike trails might be relatively easy to follow in mid-summer when many wheels pack the treadway in sections between rock outcroppings, but become almost impossible to follow from October through May as autumn leaves cover them and then get packed by snow uniformly with the rest of the forest floor. As someone who has regularly ridden these trails for 25 years even I sometimes loose the treadway in anything other than the height of summer.

In contrast, other trails in the same area are much more visible year round due to width and construction and are easily navigable by novices.

For roads there is a way of indicating that it is closed in winter - having some sort of way of indicating visibility by season seems appropriate. trail_visibility=horrible + trail_visibility:summer=good would be simple without breaking it into months to show late spring & early fall.