My apologies: I am having trouble parsing this question. Is there a missing “no” between “there’s” and “information” which would make the question read:
“Have you tried going somewhere in-person and then said to yourself, ‘No, there is no additional information that I could get here that I couldn’t alternatively get by looking at a picture of this location.’?”
Assuming that is the intended question, the answer to that question is obviously “No” – as you mention, a picture (whether aerial or street-level) cannot possibly capture every detail that could be resolved in-person.
Yes, perhaps an in-person survey is needed to determine surface material or quality, if the available images aren’t sufficient for determining those properties. (Which is why, as you mentioned, the surface=paving_stones tag in that one case should not have been added, as that cannot be confidently determined from the available imagery. Whether one could safely assume that based on confirmed details of adjacent sidewalks, and what the threshold for confidence level ought to be, is a separate topic.)
My point is that this is the wrong question to be asking: rather than “Can any additional information about a feature be found on-the-ground?” the right question is actually: “Is there enough information in a given picture (or set of sources) to map the feature?”
For example: I’m no expert on fire hydrants, but if there is a recent street-level image of a fire hydrant in a verge and I can clearly also confirm its presence via aerial imagery, I feel confident mapping the existence of that fire hydrant remotely. (I can create a node with emergency=fire_hydrant+fire_hydrant:type=pillar+fire_hydrant:position=green). However, I cannot confidently tag fire_hydrant:pressure=*, as I have no knowledge of that property and cannot determine the right value from a picture alone. Similarly, fire_hydrant:couplings=* can’t necessarily be determined from a single image: maybe there’s one on the opposite side, and I can’t know that so I shouldn’t add the tag.
Surely you agree that, given a recent-enough street-level image of a sidewalk, is it okay for one to map the sidewalk without having personally walked along it, no?
I broadly agree, though as I perceive it, this organised editing effort is not specific to upgrading from the old basic sidewalks-on-roadways tagging schema to the modern and improved sidedness approach; rather, those tag changes are one part of the overall effort to improve pedestrian infrastructure mapping.
I don’t think it is reasonable for the organised editing activity to specify every single tag they plan to or happen to edit, given that the tag change has been previously discussed elsewhere. For an obvious extreme example, I would not expect every single organised editing activity that uses JOSM to state that they intend to remove discardable tags.
That point is irrelevant, though: they do very clearly state the intention to use the sidedness tags both in the Organised_Editing/Activities/Meta/Pedestrian_Mapping page:
Once you have mapped a section of sidewalk, you should add a the tag to the adjacent road to inform OpenStreetMap whether a sidewalk exists next to that road and which sides it is on. You can do that by applying one of the following
sidewalk:both=separate,sidewalk:left=separate,sidewalk:right=separateto the adjacent road. If no sidewalk exists, you can usesidewalk=no.
and in the instructions of the Tasking Manager project:
Once the sidewalk is mapped now add a tag to the adjacent road. You can do that by applying one of the following tags to the adjacent roadway:
sidewalk:both=separatesidewalk:left=separatesidewalk:right=separateto the adjacent road.sidewalk=noif no sidewalk exists.
Though obviously still lacking consistency on whether to use the old schema or the sidedness one (why sidewalk:both=separate but sidewalk=no instead of sidewalk:both=no?) which I would encourage them to move towards exclusively using the sidedness approach and updating their documentation.
(Genuinely:) Great! Thank you for your contribution. I think everyone would agree that’s a strictly good thing.
(Edit to add:) I think that moving completely to sidedness tags to replace the equivalent non-sidedness tags is a good thing – is that what you disagree with?
I only tagged Chad because he continues to be a leading voice in the pedestrian infrastructure and accessibility mapping efforts, especially as part of the PWG, and your concern over his editing history is completely irrelevant to the content of the video, which is what I linked in response to the statement,
and which you did not address.
I took a look back through my SCEE changesets and it does seem that it’ll add sidewalk=no (example) instead of sidewalk:both=no, sadly. It seems the *=separate values, which are the majority of my submissions, are never condensed. Thank you for the correction!
Of course, and I do as well. We should point out mistakes, and we should (especially in the case of corporate organised editing activities) “hold their feet to the fire” when it comes to both fixing those mistakes and preventing future similar ones. However, there seems to be disagreement about what constitutes a mistake or what constitutes “bad” mapping, and that is what I hope we can better define.
