Check probably incorrect access=agricultural tags (and access=forestry)

[OSM-UTF-8]

General

Affected tag(s) to be modified/added: access Question asked: Is there a Sign that forbids walking or riding a bicycle?

in Germany are ~ 50000 highway=* with access=agricultural. This almost always incorrect. It is usually allowed to walk (vehicle=agricultural), in many cases bicycle is also allowed (motor_vehicle=agricultural).
This causes routing engines to avoid those ways.

Checklist

• [x] 🚧 To be added tag is established and has a useful purpose
• [x] 🤔 Any answer the user can give must have an equivalent tagging (Quest should not reappear to other users when solved by one)
• [x] 🐿️ Easily answerable by any pedestrian from the outside but a survey is necessary
• [x] 💤 Not an overwhelming percentage of quests have the same answer (No spam)
• [x] 🕓 Applies to a reasonable number of map data (Worth the effort)

Ideas for implementation

Element selection: highway=* with access=agricultural|forestry without foot=*

Metadata needed:

Proposed UI: Show examples of signs and ask if there is one of them or no sign. Depending on selection access= should be changed to vehicle= or motor_vehicle= or be removed. In the rare case, where walking is restricted, add foot=no|agricultural|forestry depending on signs. This could be redundant data, but I expect this will be a rare case.

[matkoniecz]

looking at it I see a loooooooooot of data that is almost certainly wrong

though handling access tag via StreetComplete is scary so I would probably do stricter filtering - and skip any ways that already have any access tags to avoid handling of tricky cases

I am also scared by people misinterpreting things but such access tagging is almost certainly broken, at least in Poland (and likely also in Germany)

Show examples of signs

that has problem of signs varying across world but I think that even Germany-specific quest may be worth it to fix it

though I am tempted to make thread at community forums to get feeedback (on the other hand feedback will be likely self-contradictory and/or confusing and/or confused)

for now I opened few probing notes

[westnordost]

How does the sign for "only agricultural vehicles" look like? And I guess, your point is that this sign (in Germany) only applies for motorized vehicles?

[matkoniecz]

In Poland I have not seen one.

vehicle=forestry sort of fits for "no vehicles sign" with plaque with text below it stating "with exception of state forest vehicles" or similar. Though that is more fitting vehicle=private

[rusty-snake]

Also https://trafficsigns.osm-verkehrswende.org/DE?signs=DE:240,1026-36

[OSM-UTF-8]

The prohibition signs in Germany that I expect on those ways are DE.250 for vehicle=no and DE:260 for motor_vehicle=no

These signs are modified with the additional signsDE:1026-36 which cahges =no to =agricultural, DE:1026-37 to =forestry or DE:1026-38 to =agricultural;forestry

Additional modifier is DE:1022-10 for bycicle=yes.

[westnordost]

If the sign is that clear, then it looks like a pretty sloppy oversight if those were tagged with access=agricultural. I mean, is there even a sign that would mean access=agricultural?

A quest like this should show the different signs for users to select, and thus would require some research: If the tagging issue exists in other countries as well, it would make sense to check which signs exist there and display the correct signs depending on the country. (If the signs are very similar, we could make a graphic of a generic sign that would be recognizable in all those countries as the sign for agricultural motorized vehicles only, like I did for living street signs)

I usually don't implement country-specific quests, but if there's interest from someone else to implement it, I'll not say no to a PR.

[OSM-UTF-8]

I do not know any way where access=agricultural without other access tags is correct. In Germany a combination of at least 6 Signs is necessary for access=agricultural: DE:250;DE:1026-36;DE259,DE:1026-36;DE:257-51,DE:1026-36 to forbid vehicles, foot, and horse, each in combination with the exception for agricultural purposes. As it would be ridiculous to put all those signs together, I expect it to not exist.

There is a combinations of access=agricultural without foot that is probably somewhere: cycleway with exception for agricultural traffic:access=agricultural bicycle=designated. Limiting the selection to access=agricultural|forestry` without any other access related tags would avoid such false positives.

If no one else implements this quest, I will probably try it next month. But this would be my first programming for any smartphone app, so I am not sure if this will be successful.

[matkoniecz]

I do not know any way where access=agricultural without other access tags is correct. In Germany a combination of at least 6 Signs is necessary for access=agricultural: DE:250;DE:1026-36;DE259,DE:1026-36;DE:257-51,DE:1026-36 to forbid vehicles, foot, and horse, each in combination with the exception for agricultural purposes. As it would be ridiculous to put all those signs together, I expect it to not exist.

can you get it via putting "no vehicles" + "no pedestrians" + text label below "farmers are exempt"? Or via closed gate with note "for agricultural access call XYZ to open gate"?

Though I expect about 50 such cases to exist across Germany, not 42 270 of them

But this would be my first programming for any smartphone app, so I am not sure if this will be successful.

probably depends on how much programming experience you have - this is relatively complex, but app programming is not completely disjoint from programming in general

I guess that going for Germany only quest would make sense in such case

and this one has potential to fix a lot of bad data!

[rusty-snake]

My "Suspicious access" access list: https://github.com/rusty-snake/SCEE-custom-overlays?tab=readme-ov-file#suspicious-access Note that this is just a suspicious access and not a wrong access. Although 60-90% of the cases they are wrong. That's why I highlight them. There are much much more wrong access tags in OSM, but the most of them are not a simple "usually wrong, check".

[matkoniecz]

For Poland data is so obviously bad that I proposed https://wiki.openstreetmap.org/wiki/Mechanical_Edits/Mateusz_Konieczny_-_bot_account/retag_access%3Dforestry_in_Poland to local community, that would retag access automatically from access=forestry to motor_vehicle=forestry instead of going through a SC quest.