How wide does a shoulder need to be to count as a shoulder?

[endolith]

I frequently see cases where there's a white line, then maybe a few inches of black, then a curb, and the distance between the white line and curb varies as I'm driving, so I'm not sure what to put for these unless it's very obvious.

StreetComplete says "not necessarily wide enough for a car to stop completely off the traffic lane".

https://wiki.openstreetmap.org/wiki/Key:shoulder says:

Unless otherwise tagged, a shoulder should be assumed paved, wide enough to be used as an emergency refuge for cars, and wide enough for through passage by bicycles.

which would seem to imply that a car needs to fit in the shoulder to count?

[mnalis]

I think the intention of that wording is that is acceptable that some (small) part of the car parked on the shoulder remain on the driving lane, as long as it does not obstruct cars driving on that lane.

E.g.:

• if 90% of the car fits on the shoulder, and 10% on the driving lane, it is probably OK and it is a shoulder.
• However, if only 20% of the car fits on the "shoulder", and 80% must remain on the line used for driving (which would likely stop all traffic in that lane!), then it is not shoulder at all.

Finding the exact line between those two extremes is a matter of personal judgement - would you feel secure stopping your car at such "shoulder", while other cars buzz on the lane beside it? If so, it is probably a shoulder. If not, it is not.

[endolith]

OK, so it's car-centric? A narrow shoulder could be useful for bike travel

[mnalis]

OK, so it's car-centric?

Yes, car-centric, see the shoulder=* wiki that StreetComplete follows. It also mentions alternatives like verge=*, but those are not supported by StreetComplete.

Also note that the full SC explanation text is A shoulder is a clearly demarcated emergency stopping lane that allows vehicles to stop safely completely beside the traffic lane, though not always (fully) on paved surface.

So shoulder might be for example 70% marked on asphalt, followed by 30% compacted surface, as in this picture on the left side:
https://en.wikipedia.org/wiki/Shoulder_(road)#/media/File:M4_Heading_west_at_J11_(start_of_the_N6_near_Kinnegad.jpg

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A narrow shoulder could be useful for bike travel

Shoulders are not (at least in vast majority of cases) used for moving traffic, but for stopping in emergency. If some narrower lane exists on that road, and is wide enough for bicycle traffic (and bicycles are allowed to ride on it!) then those are not shoulders but bicycle lanes and StreetComplete have separate quest for that: Is there a bicycle lane or path here? What type?

If it is wide enough for bicycle, but it is illegal to drive a bicycle on it, than it should not be mapped as bicycle lane, but maybe as verge=* with appropriate width=* and surface=* for example. But one would have to use some other, more complex editor than StreetComplete to do that (for example Vespucci if using mobile device)

[westnordost]

Not entirely, @mnalis . Basically the wiki page says everything that can be said about this tag. Yes, it is fuzzy. Yes, there is no hard limit (defined) how slim it may be to still count as a shoulder.

Refer to the talk page also, I did a little research how the shoulder=* tag is used in reality:

https://wiki.openstreetmap.org/wiki/Talk:Key:shoulder#Documenting_definition_of_shoulder:width

[mnalis]

Well, wiki does say at some point (in its current revision at least):

Unless otherwise tagged, a shoulder should be assumed paved, wide enough to be used as an emergency refuge for cars, and wide enough for through passage by bicycles.

But yeah, you did some useful research there ❤️. Looking deeper into Talk page, however, I'm even more confused about what is assumed by this tag, i.e. what useful purpose can it serve to data consumers in its current state (when different mappers mean wildly different things when they use the same tag). Especially if shoulder:surface and shoulder:width are not mapped 😕

[westnordost]

Yeah, it's really not in a good shape. That the definition is so blurry only came to the surface after i implemented that quest though.

It would be better if shoulder was to be replaced or to be joined by other tags that allow the different types of "shoulders" to be defined more precisely.

There is the hard shoulder (paved), the soft shoulder (unpaved, but maintained) and the verge (grass, not maintained as emergency stopping). Ideally, they should each have their own tag. Currently, at least the first two are muddled together.

[westnordost]

Did someone just delete a spam comment here or is this done automatically by GitHub (once an account is determined to be a spam account)?

[matkoniecz]

I deleted one. It was a blatant porn spam scam by now deleted https://github.com/LauraRobinson2189 account, I also reported account to GitHub. Earlier I got multiple phantom notifications across multiple discussions, across multiple repositories - I assume that it was also now deleted spam.

[mnalis]

I've received notifications for at least 8 other GitHub spams in StreetComplete repository (each by different account), but they were all gone by the time I got to them.

[matkoniecz]

shoulder quest was disabled in 04a976d - see https://community.openstreetmap.org/t/shoulder-tag-is-confusing/5185 and #4617 (comment)