Kerb / Curb quest surface type and tactile plates for sidewalk data

[omgitsgela]

I am suggesting here two quests related to inclusive pedestrian mapping as defined in https://wiki.openstreetmap.org/wiki/Sidewalks. This has the potential to affect a large amount of kerb ramp data in a positive way.

General

1. Define what type of kerb interface a crosswalk has to a sidewalk Affected tag(s) to be modified/added: [kerb=] https://wiki.openstreetmap.org/wiki/Key:kerb Search for type=point ; barrier=kerb, which should define a single node on a highway= segment Ask "How high is this kerb ramp?" Answers: flat ; lowered ; raised

2. Ask if a kerb ramp has a tactile plate that would be used by the blind Affected tag(s) to be modified/added: tactile_paving=* Question asked: Does this kerb ramp have a tactile plate for the blind? Answers: yes ; no

Checklist

Checklist for quest suggestions (see guidelines):

• [X] 🚧 To be added tag is established and has a useful purpose Purpose is to enhance the inclusive pedestrian network tagging through revision of kerb ramp data to enhance overall accessibility for patrons requiring accessible infrastructure
• [X] 🤔 Any answer the user can give must have an equivalent tagging (Quest should not reappear to other users when solved by one) Tags are well defined for both quests proposed.
• [X] 🐿️ Easily answerable by everyone from the outside but a survey is necessary With the proper graphical elements in the displayed quest, this would be answerable by anyone.
• [X] 💤 Not an overwhelming percentage of elements have the same answer (No spam) These are roughly boolean options, and so many will have the same answer, but I wouldn't consider this spam, rather, completion of features that should be documented for proper routing.
• [X] 🕓 Applies to a reasonable number of elements (Worth the effort) Has the potential to improve a vast amount of kerb ramp data.

Ideas for implementation

We should use graphical depictions of the kerb ramp heights to show people what the different types are. There's very good graphics available on the Key:kerb page for each option.

We should also use a graphic to show a tactile plate, so people know what it is when asked.

[LorenzoStucchi]

Not depending on the type of mapping decided, I found an error.

The app proposed the quest for all the nodes that satisfy the characteristics requested, so if in a crossing there are nodes tagged as barrier=kerb and them are not the node in common with the sidewalks, the app adds the quest also on these nodes.

Here an example in the app: The same way in OSM

The nodes (1) and (4) are the junction with the way mapped as the sidewalk, instead, (2) and (3) are mapped with barrier=kerb. So the app ask for the presence of the tactile paving on all the four nodes. This should be solved that if in a line there is a node with the barrier=kerb (2) and (3), the app should not ask quests for the external nodes (1) and (4).

[westnordost]

Ehm, I have the impression we are going in circles. Maybe there was a misunderstanding due to the language barrier. I'll try to make it clear:

Here is the linked situation with labels.

I painted the kerb line you assumed onto the screenshot in grey since the photo resolution is so bad. Rhetoric question: So, if the kerb is there, why then is the section circled in red a highway=crossing, if it is still on he sidewalk?

I assume the answer to that is because you map with this scheme: i.e. if the part of the crossing is still on the sidewalk, it still counts as part of the crossing and not part of the sidewalk.

Fair enough. But then, please mind what I wrote in the comment above: https://github.com/streetcomplete/StreetComplete/issues/1305#issuecomment-759709100 . This comment summarized: The shown intersection is incomplete. If you are not going to map the sidewalk in Via Trento now, you must do this:

You must lead the sidewalk back to the street with such "helper lines" at the points where you stop the detail-mapping of sidewalks, otherwise data consumers will not be able to ascertain the sidewalk situation correctly / route pedestrians correctly. I explained it in more detail why this is the case in the linked comment. The last two pictures in that comment should be informative.

[LorenzoStucchi]

I painted the kerb line you assumed onto the screenshot in grey since the photo resolution is so bad. Rhetoric question: So, if the kerb is there, why then is the section circled in red a highway=crossing, if it is still on he sidewalk?

Yes, but if you think in the case of a street. Two street are mapped as (a) or (b)? The small part in red is on the red streets but it is usually mapped as separe streets, so like (b). The schema should be the same, why it should be different?

(a)

(a)

(b)

(b)

Fair enough. But then, please mind what I wrote in the comment above: #1305 (comment) . This comment summarized: The shown intersection is incomplete. If you are not going to map the sidewalk in Via Trento now, you must do this:

This is wrong, in that street, there are no sidewalks.

You must lead the sidewalk back to the street with such "helper lines" at the points where you stop the detail-mapping of sidewalks, otherwise, data consumers will not be able to ascertain the sidewalk situation correctly / route pedestrians correctly. I explained it in more detail why this is the case in the linked comment. The last two pictures in that comment should be informative.

And what is the meaning of the triangle? It is not needed, the router will use the crossing to reach the street and after will use the road, if needed. So the triangle represents somethings that do not exist and it is useless for routing. And remains in the same case as before, and if there are no sidewalks in the street, is this incorrect mapping? No.

Hoping to close this part, I believe that both the schema are suitable, my last question is why the app asks for attributes on external nodes when there are already nodes in the way with the tag barrier=kerb?

Sorry, for all these long comments, but I think that the mapping with the StreetComplete app is very suitable and useful for people with physical disabilities, and I would like to propose this solution to them for the mapping.

[westnordost]

This is wrong, in that street, there are no sidewalks.

Ok, I didn't know that. But in that case , it makes no sense to map it like that

because if there is no sidewalk in the road going North, the piece of sidewalk beyond the kerb should not be part of the crossing by any definition (neither (a) nor (b) in above examples). It should look like this:

[westnordost]

For comparison:

This is fine for StreetComplete, the app will not ask for kerbs at the blue rectangles

[LorenzoStucchi]

Ok, so I ask you sorry. If the situation in the last picture is what happens in the app, it is ok so with both the tagging schema. It is only needed to map the yellow square with the tag barrier=kerb. Is this correct?

[westnordost]

Ehm, I am not sure if I undestood your comment.

First picture: Streetcomplete asks for the kerb type for the blue squares Third picture: StreetComplete does not ask for the kerb type for the blue squares