Personally, I like to map gates. Today I happened over this gate:
As can be seen, it is locked – by snow. But this is just a coincidence. I chose to tag locked=no.
Is it wrong to tag foot=yes there? From reading this topic, I’d say, yes, this is wrong.
First of all, the snow probably definitely falls under the guidance against mapping temporary events. 
Aside from that, the fence is clearly designed for foot traffic, but if the lock prevents access anyways, it should be indicated somehow. locked=yes would be an elegant tag for that, although unfortunately, Organic Maps is the only router I know of that supports it so far.
Note that locked=yes only applies when a lock impedes pedestrians, whereas foot=private or foot=no could also apply in some other situations, such as an inoperable gate in an otherwise impenetrable fence, or an unlocked gate that’s only large enough for a dog to squeeze through.
@Minh_Nguyen @SomeoneElse In the same CS I also did add a locked=yes, screenshot with lock
and a plethora of access tags. BTW: There is no track there, at least as I observe.
PS: In case of being fond of mapping gates certainly will share delight in this File:Gate and Stile with Dog Gate.jpg - OpenStreetMap Wiki
@Minh_Nguyen, would love to hear your routing expertise on that topic. 
e.g Is there a fundamental difference for routers between the two tagging options?
Off the top of my head, Valhalla has an option to bias the route against following a highway=service service=alley, which wouldn’t recognize highway=residential lanes=1. On the other hand, I don’t know if any router specifically penalizes a one-lane road of any classification in the manner that some mappers would expect.
But the aspect I find more interesting is that many narrow alleyways would discriminate against a subset of a legal vehicle classification, so legal restrictions are somewhat irrelevant:
This is actually a very minor use-case only found in old major urban centers. Some one-way and residents only signs are finally popping up after likely some incidents happen with larger vehicles or drivers unfamiliar with the narrow roads 
Thats actually a more concerning and pressing issue as most residential roads in Thailand are not wide enough for 2 cars to fully pass. What other tags would penalize these narrow roads? access=private?
It might be more minor in Thailand. I know it’s a big deal in Japan (comes up in discussions with delivery companies) and Vietnam (where plenty of roads are designed for motorcycles rather than cars anyways).
No, as I pointed out above, access=private would make no sense if access tagging were solely about physical accessibility. Let’s continue the discussion about narrow roads in the other thread; I’ve already finished making my point that physical accessibility matters.
I would not consider the snow, from what it looks, this is not designed to be locked any time or prevent access for people, so I think foot=yes would be suitable (but you know the situation better than me, I have to guess from the picture).
Tagging such would NOT map legal rights of way, but the physical ability.
From this topic I infer, foot=yes would not say anything about passibility. So I went with locked=no.
PS: The path the gate is on has sac_scale tagged, so foot=yes is implicit, on the path, and I suppose on all the hurdles.
What is the legal situation, may you cross this gate on foot or not?
I am not sure if there is consensus (yet) to start documenting on the Wiki.
Let’s look again at the example that led to this thread: bollards that block cars from driving on a cycleway but are far enough apart so mopeds fit through. The Dutch agree that even when mopeds are allowed on the cycleway, barrier=bollard by itself is sufficient, there’s no need to add moped=yes, the node should not prevent the moped from being routed along the cycleway. Elsewhere (e.g. Germany, UK) where mopeds are not allowed on cycleways, mappers also agree that a simple barrier=bollard node is fine: even though mopeds aren’t allowed, we don’t tag it moped=no (nor do we tag it as moped=yes just because mopeds fit past). So there is no real disagreement about the tagging, it’s just a question of how we document how we map on the Wiki.
Then there are cases where there are actually different tagging approaches. They are probably not that common but still common enough to think about. A landowner has illegally put up a locked gate across a public footpath, is that foot=no or is it foot=yes but locked=yes? A fence has appeared and I have absolutely no idea if it’s still my legal right to access the land behind it - I am not a lawyer - but what I do know is it prevents me from accessing it without climbing over it, is it OK to still tag foot=no? You have to carry your mountain bike over a stile but you can legally continue on the other side, should I tag the stile as bicycle=no?
How do we document this situation on the Wiki and explain it to new mappers and data consumers? Do we say
maxwidth:physical, locked, …)yes means allowed and possible, and no means either illegal or impossibleIf we don’t make a decision we end up with (5): the Wiki says completely contradictory things in different places 
I agree these are worth discussing. For clarity I think the examples should also include cases where signage might be illegal, either because somebody puts in place a sign where they have no legal right to do so, or because they destroy legal signage.
I can think of an example in Ireland where a dispute between a landowner and local authority about access to footpaths went all the way to the Supreme Court, a 58 day (!) trial, and several million euro of legal costs. During a period of around 5 years, it would have been impossible for a mapper to determine the legal access rights.
For these reasons I don’t see the distinction between legal and physical access as clearly as some people seem to. As a practical matter, don’t we generally have to assume that physical barriers reflect the legal situation, unless there is specific reason to think otherwise?
Note I am talking here about intentional physical restrictions, not (for example) a path where bicycle access is legal but the condition of the path makes it unsuitable.
I think so, but it seems like there’s some contention over whether mappers are also responsible for evaluating the effect of a barrier’s design. A closed gate is relatively straightforward – literally an open-and-shut case – compared to a bollard or other permeable barrier. As much as I hope that more routers adopt locked=* over time, I can easily imagine a long tail of other micromapping that routers would now need to understand if we handle physical passability with the same precise fervor as legal permission.
Incidentally, where was the concern about ambiguity when we decided that wheelchair=* would simultaneously describe physical passability (by virtue of values like limited) and legal permission (by virtue of its inclusion in the access key list)? Does this sign indicate a lack of permission or of physical access?
where is it? And what is the local context?
There’s a description on the Flickr page. I think it’s somewhere around here. Apparently the walkway goes up a slope that’s uncomfortably steep for most wheelchairs, so the college repurposed a sign for a disabled parking space to discourage wheelchair users.
Probably on a mailing list somewhere
Around about that time (2010) there was also use (in England at least) of “bicycle=no” on signed cycle routes that you may not want to take a regular road bike on. That usage has significantly decreased as people have discovered other tags to express the same issues.
The context of that sign makes clear it’s a lack of physical access in this case. Whether it’s a lack of legal access as well is likely dependent on local law around disabled access - at least in the UK and I believe the US (where this sign is), there’s explicit legislation that tries to ensure legal wheelchair access in a bunch of places where physical access might be difficult or impossible.
Huh, I’ve never thought of wheelchair as an access key, precisely because it’s so commonly used to mean “suitable for wheelchairs” and that is also the meaning documented in the Wiki. I didn’t know it was listed on the Key:access page. Should we just remove it from there and instead add a note that it works differently to the legal access tags?
There’s more where that came from. The page on mtb=*, which is also in the list, has a whole treatise on whether it accounts for legality. dog=* tends to be used in a less legalistic fashion on amenities and shops. 4wd_only=* is an oddball in multiple respects.
Best to avoid getting involved? A way with incline > 6% legally is wheelchair=no in the sense of “impassable” in the area of my local knowledge. I rather tag incline than wheelchair and leave it up to wheelchair-client to decide the other.