RfC: Have pathless hiking routes (no trail_visibility) be some manner of related nodes instead of paths

[erutan]

@Hungerburg

In my area, trails where on the ground there is not much bootprints, but where there is a steel cable running all along (not of the via_ferrata kind, but the assisted_**trail** kind), get tagged trail_visibility=horrible. If trail_visibility is to start meaning any clues, we have to change some mappings, some dating back ten years.

That’s an argument for this thread Tag trail_visibility: Proposed Improvements for this Descriptive Tag - #87 by erutan. I’d personally consider a steel cable as designating a path, similar to a line of rocks.

@StC

maybe I’m becoming too conceptual here but could we say that, in the universe of routes (people advising other people where to walk), a path is a special case of route? That is, it has its own way of conveying information whereas other routes rely for that on cairns, on signs, on lists of pre-existing routes, etc.

This would open a way to situations where a route can be made of routes that are either paths, composite routes themselves made of other routes… and other objects (non-paths) made for instance of ordered lists of nodes ?

I think that makes sense, and that a “path” is a special kind of route which has to have trail_visibility. (linked to above, currently a matter of some controversy). The Sierra High Route is 200+ mile route that is a mix of official trail (paths), social/informal trails (not maintained, which have visible wear to follow), and off-trail routes.

@StC

What if what we need is routes that can be routable even though they contain elements that are not ways? It would be the responsibility of apps to decide how to render series of cairns, areas, etc.

I think having a top and bottom node would allow for “routing” connecting it to paths in a mapping application. That would then require that said nodes connect to a path, which isn’t always the case. In the Little Joe Pass example above with four nodes, the top of the pass opens into a SAC 1-2 open area which one can then routefind to the nearest trail as they see fit. There’s a few options but they are all a few miles away and creating an arbitrary route just to allow for that case doesn’t seem appropriate to me.

OpenStreetMap there was an existing path here that I deleted from OSM because a) it had no ground truth b) it made some poor routefinding decisions leading from lake reflection to the base of the pass.

I’m pretty sure the nearby Millie’s foot pass doesn’t have any ground truth, but haven’t verified that.

Harrison Pass follows an old trail that hasn’t been maintained for 90 years, but a path probably exists in some fashion except for the steep northern part of the pass where there’s been enough collapsing terrain that it’s gone.

These are sort of “power user” type things and I’m not sure someone that wants to find the fastest way from A to B should have off trail routes included in that by default.

@osmuser63783

Thinking about the data model, there are nodes, ways (= ordered sequences of nodes), and relations (= ordered sequences of nodes, ways, and relations).

For routefinding in the wilderness, @erutan would like a way to describe a route as a series of way points without having to draw a highway=path between them. I can relate to that. A lot of hillwalking routes in Scotland are variations of the form “park your car at spot X, walk to the saddle, then follow the ridge to the summit and back down again”. To draw a highway=path here, with trail_visibility=no trailblazed=no, would essentially be troll tagging. If people in the US have been doing that, it’s natural that we should look for a solution.

Now, it seems to me that there are two questions here. The first is, how can this be represented in OSM? We would need new tags for the nodes, to say that they are waypoints. @erutan has made some suggestions. For simple routes, an ordered list of nodes can be represented using a way whose elements are the way points. You don’t need a relation at all. In fact, the typical route=hiking relation is a sequence of highway=path objects (or similar), and that is exactly what we don’t want. The question is just, what would be an appropriate tag for such a way? pathless-hiking=route? And when the situation is more complex, because there are alternative way points, what would a suitable relation look like to hold this data? Should this be modelled after how climbing routes are mapped, or after how node networks are mapped, or some combination of both?

The other question is, should this data be in the OSM database at all? Are such routes verifiable? Besides, you can already map summits, saddles, cairns, and (for better or worse) arbitrary named locations, so how much would it add to group them in a relation? I think many of these questions need to be answered by more experienced mappers than me… but it seems to me like these are the questions we need to be thinking about?

If a tagging scheme can be agreed, we would then need to lobby existing data consumers to support it, or new maps and apps would need to be developed.

The ‘alpine routes’ that have been discussed here are a little bit different, aren’t they? When there is an obvious route between two way points, because you follow an arête or a steel cable or way markers (trail blazes) placed every few metres, there is a verifiable geometry that can already be mapped as a way using established tags. So if these should come under the same tagging scheme, then we would need relations that sometimes consist just of nodes and sometimes consist of nodes and the ways between them.

We’re definitely on the same page here!

As to “alpine routes” I’m not familiar with the ones in Europe, in the US they are generally informal and don’t have Via Feratta, though climbing_routes will often have bolts on them which may or may not be officially sanctioned. Any markers are informal user made cairns, which may or may be helpful (some people cairn bad routes - I generally ignore them unless they’re marking the top or bottom or something to be honest).

I would say if there’s markers every few meters that would fall into a path… there’s technically some routefinding to be made between each marker but that’s within the margin of error of GPS for someone checking the path on their phone or other digital mapping device and there’s no real experience needed in routefinding or orienteering as you can presumably find the next marker easily, that’d fall under trailblazed:visibility=good or trailblazed:visibility=excellent.

@rhhs

@osmuser63783

The other question is, should this data be in the OSM database at all? Are such routes verifiable?

Exactly what I was thinking! I understand that what @erutan calls a node network is like a series of ordered “virtual cairns” that suggests a route where there is no visible path (or markers). I think it is a good idea by itself, but in the spirit of Wikipedia:No original research - Wikipedia, it should be developed outside OSM. Once such a system of virtual cairns is established and made official (by a National Park authority, the American XC Association (if it exists), etc.), we can quote them by adding these virtual cairns to the map. Adding them to the map without some form of official endorsement, they would be like

I honestly wouldn’t mind a policy that just bans pathless routes, but there’s an appetite for them and having something like a relation of nodes to me seems like a possible compromise.

In the Sierra Nevada a lot of these pathless routes are marked by a saddle feature, which is not actually a saddle feature (see little joe’s pass above). This indicates that a pass is there, but doesn’t say anything about the safety or ease of reaching it (some are simple, some are deadly). If we can have the top, why not the bottom (which in some cases is just as important), if we can have the bottom, why not a few points in between… it’s a bit of a slippery slope argument, but one that I think needs to be addressed.

@rhhs

In my early days as a mapper, I did add paths to the map in mountainous areas based on GPS tracks I found on Internet, not even knowing if they represented visible paths or not. My motivation was to help other hikers and myself by showing that “this is a safe way to cross that pass” and to be able to get an idea of distance and time needed to hike that path (using a routing app). What I should have done it to upload those GPS tracks on my own phone, and upload my own GPS tracks to wikiloc to show people where it’s safe to go.

What we can do, of course, is to add information to the map to show hikers where it’s not safe to go, such as cliffs and screes, as long as they exist on the ground.

(off topic) On the topic of not promoting the creation of more informal paths, the European approach (by National Parks and the likes) is often to provide (marked) paths on purpose while at the same time forbidding hiking outside those paths. In stead of spreading the bootprints as much as possible like the American XC community tries, the Europeans generally try to concentrate them on a limited number of paths so that the rest of the area stays undisturbed.

I’m not sure about marking out scree/talus fields that are unsafe - a lot of times that comes down to individual experience and skill. I’ve “boot-skied” down collapsing scree and found it fun, while my partner shook her head and just potholed down a steep snowfield (that I didn’t feel comfortable on). Some named off-trail passes & cols include unstable talus, others are simple walks, and others require some simple climbing. Cliffs should already show up via the new high resolution slope angle shading, at least in most of the US ala Latest High Resolution Elevation Data Updates - CalTopo

Some areas of the US ban off trail travel, or do so in specific fragile areas. I think a major factor is we just have a lot more wilderness that hasn’t been impacted for as long - I do enjoy how entire basins are left pathless instead of building trails up to them and I do my best to destroy any cairns I see in them.

I’m not sure about how to mark that (having an area that overlays terrain would be noisy) but it’s something to considered even if there is “ground truth” for an informal path. There are some tags for paths that are not recommended by land managers if I recall.