I’d go as far as to say: scratch the aerials. If I come across a path on a hike I map that path because it is there. I see it, I map it.
Everything has been said in that MTB trail thread in the Canadian community.
9 Likes
“Aerial imagery” and “ground truth” are not quite the same.
1 Like
You should read through this thread from last week.
5 Likes
Thank you for pulling that up 
Trailforks is using OSM data but we do not control their app. Trailfork-specific suggestions should be send to them.
8 Likes
Why Map Sensitive, Illegal or Hidden Trails?
Simply to let people know they exist.
“Sensitive” is too subjective to consider as a reason to map or not map something. “Sensitive trails” need a change IRL, like improving safety for people or closure to protect nature. This is already common in some nature reserves, which close certain trails during the breeding season of certain animals.
“Illegal” is usually tagged with informal=yes and/or access=no, depending on the context.
“Hidden” trails are not so hidden anymore if there is open data for them. The owner or operator of a trail on private land may of course deny access to the trail, in which case we add access=private.
We won’t delete anything unless the trail is overgrown with vegetation or otherwise erased IRL.
See also the relevant guidelines for OSM mapping:
Map what’s on the ground
Why we won’t delete roads on private property
Why can’t I delete this trail?
Mapping private information
5 Likes
Many supposedly hidden trails are also visible on Strava as people MTBing there are not even trying to keep them secret.
though also supposedly secret military bases we found this way
4 Likes
I am not aware how something that was not built on purpose, a.k.a informal=yes would be illegal per definition. Perhaps some parties would like to conflate this and the term access=no. In my jurisdiction this will not hold.
paths across railway tracks, outside marked crossings are one of obvious cases (qualifying for access=no and informal=yes, though I never tagged second one)
So what ?
You were asking how something that was not built on purpose, a.k.a informal=yes would be illegal. I gave an example.
Sorry if I misunderstood your post.
1 Like
I have got several trails that i dont want to show up on OSM carto
The only way to keep it so is come to a conclussion with all mappers who are interested in that area.
The rules say we map what there is and the only option there is decide otherwise, but can’t force anyone for that.
I have got a path through a small nature reserve where it’s simply not allowed to go outside the official path and that’s because what’s especially protected in that reserve is actually the ground.
Sure people just walk around from memory without looking at a map or strava heatmap, but mapping it encourages more people to destroy what’s protected as a heritage.
There are also other paths like mtb trails that if you map em, forestry can come and destroy em coz they may be obliged to do so and not so much if not on map for everyone to see.
So yeah, talk to people, don’t be forceful even if that may be difficult
1 Like
access=no is your friend.
That’s a weird way of saying “informs them that they shouldn’t walk there even if it looks like a walkable path”
I would hazard a guess that either you can talk to them to keep it, or there is a reason that obligation exists. Either way, mapping the trail doesn’t have anything to do with that.
8 Likes
To me this conclusion seems counterintuitive. If there is an official path that one should not deviate from, surely it would be beneficial to map that exact path, then.
We simply can’t help if people do not have maps or do not observe legal, restrictive signs present at these places. What we can do, however, is map paths that are on the ground with the appropriate tags.
5 Likes
you’re missing the point
If there is informal path that can be allowed to enter under a permit for instance, you map it, so people know how they can get through a forest quickly when they actually have that permit.
If you map a military base at Ruzzia occupied territory of other nation, which is illegal not only to enter or even map, should you obey ruzzian law or the occupied country law, or just UK law?
If you don’t want mapped something that actually is there. Talk to other mappers and convince em.
This is the way.
1 Like
Yeah, I think there’s something lost in the translation and we are talking past one another.
1 Like
In the 1920s, British mountaineer George Mallory kept trying to climb Mount Everest. He was asked why he wanted to climb it. “Because it’s there” was his answer.
Why map trails? Because they’re there.
11 Likes
Yeah, I’d also strongly advise against mapping based solely on non-ground-truth sources like aerial imagery or GPS traces without local knowledge.
Data based on estimation can easily lead to issues—like unsafe routing or accidental mapping of restricted areas. Ultimately, we should encourage responsible mapping: trails that have been properly ground-surveyed are far more useful and reliable for end-users.
Not everyone relies on routers, so simply tagging something as access=no or private isn’t always enough to prevent people from using a sensitive or restricted path.
More on this here: https://community.openstreetmap.org/t/should-every-trail-be-mapped/116151
2 Likes
…assuming the app they’re using respects access tagging, which doesn’t seem to be as common as we’d like 
I’m not sure what can be done aside from hounding developers to improve their apps. Agree that deleting paths definitely isn’t the solution.
3 Likes
Apparently you don’t, otherwise this whole situation and this thread wouldnt have happened and we’d all be happier for it.
You may not be the ones trespassing, or directly cause it, but publishing sensitive trails legitimizes and encourages access. That influence carries responsibility.
Who made you lot the authority on trails? What if the builders only want people who discover the trail organically?
Plus, members of this community continue to add trails without proper data, incorrect or missing names, missing difficulty and access rights data. They continue to add trails only from GPS tracks and heat maps scavanged from other online sources. They also aren’t keeping up with trails that are now not in use, totally overgrown and non functional. And on top of all that I can see legal, marked and sanctioned trails in the area that aren’t added.
All of which makes me question the true motivations of at least one particular user.