Shortening the description in the wiki a bit, ”Route designated/preferred for this tag key.”
That’s kind of the point here right, that motor_vehicles isn’t the correct key. Of course this might then make the mapper look for/create agricultural_motor_vehicles key, because access=agricultural doesn’t fit the pattern…
In German might be very easy: Gewidmete Nutzungsart – in English then Designated Use – keep it short. The Upper keys also do not say: Yes|No according to local rules or signs, don’t they?
If that is considered fine here, I will open an issue in the repo.
PS: I bet out of the 48 uses of the tag in the area of my local knowledge, all are for the prohibitive sign. No idea about the 60,000 ways worldwide.
Designated is not just allowed, it’s also designed/appointed to be used by xyz. Something says “xyz-pilots, we designated this way to you. You’re welcome.” A sign is fine, markings may do the job, or a design that conveys the information. If it’s recognizable by any earthling, great, if it’s not but local people know it for a fact, based on what it looks like and the applicable legislation, it’s still ground truth and it’s what should be mapped.
That’s why it’s important that local mappers take this on, so they can translate the local ground truth to OSM-tags we all know. Tell us aliens how it is, so we know and do the right thing!
I would be intrigued to know how many data consumers actually use =designated as anything other than a synonym for =yes. My suspicion is “really not very many at all”.
(Spoiler: cycle.travel uses it to inform a couple of edge cases, but the only one of any real significance is the highway=residential/bicycle=designated combination which is used in some places as an unwieldy, unclear way of indicating a fietsstraat.)
Designated is a yes for access, and possibly a plus for weight ( or whatever a router uses to indicate relative preference of candidate ways). Weight can be set in the user profile, so the question is: how many end users use designated different then just yes.
I suspect that’s correct - the only non-editor listed in taginfo is OsmAnd, and that just says “Used to create maps”, which is what it says for everything. What seems to be the default rendering style just uses motor_vehicle=designated as a synonym for yes.
I see. The English phrase does a bit better. At least it says, that access is to be taken for granted. While the German one says nothing about whether access is allowed or not, just that signs or local rules apply.
Toying around with the iD editor a bit more brings up another gem when clicking the “i” button I get to see something that looks much like what is on the sign:
I guess some people read “designated” as “There are signs like that there.”
Still wondering why there are so many uses of that tag in other places. Are they just as wrong (mapping the opposite of what is) or are there legitimate uses of that tag?
Motor vehicles are allowed there, but it’s not in any way different from all the other service paths.
I guess if you really wanted to lean into the car centric mentality, you could argue that this path was specially built for cars (it didn’t have to), but that seems like a bit of a stretch.
Used a variant to look at Nederland. Result: 410 ways. Randomly checked some:
Short stretches of cycleway and other minor roads are probably meant as motor_vehicle=destination or motor_vehicle=delivery because of a traffic sign. “motor_vehicle=designated” is either redundant or wrong in the whole sample.
I can’t check them all from aerial imagery or by survey, though. Can’t be helped. Could be a candidate for a MapRoulette mission.
Carto renders highway=path + bicycle=designated (but not bicycle=yes) as a cycleway. This reflects widespread usage where JOSM proposes highway=path + bicycle=designated + foot=designated [fixed] for shared cycleways. It’s not very logical, but then it is hard for data consumers to know what to do with highway=path.