I was working through my Draft for US cycling and I will not a possible source for something that I think we do align on.

https://wiki.openstreetmap.org/wiki/Crossings

This has multiple instances of ‘crossing:markings=yes’ listed multiple times and I think I’m in alignment that if people are going to bother marking that an intersection has markings that ‘crossing:markings’ should be used to specify the type of marking and yes should rarely be used. (Like some odd undocumented or unrecognized marking.)

I want to first recognize that I’m presently working on a similar line of thought at you with the Draft-US-Cycling Wiki page. This is becoming the culmination of multiple 7 years of mapping Bike-Ped in the fastest growing Cycling regions in the US possibly the world which spans multiple cycling types. I’m learning a lot as well from the Pedestrian working group of OSM US as well. Please feel free to review what I have linked above and provide feedback. I’d really love review even if this is a developing draft.

“A simple unmarked, uncontrolled crossing is just an intersection node without any tags.” - I would always mark a crossing as marked or unmarked as a minimum but I typically draw the line on node vs. way marking as nodes are curb cuts for business and I’ll to the way for intersections if time is a factor.

I’ll echo what Sienna stated though although iD editor cause ‘crossing=zebra’ to shot up in prevalence there has since been discussion of separating if there is marking from the type of marking thus crossing=* + crossing:markings=zebra is now preferable even if crossing=zebra by prevalence with likely remain acceptable for a good time still.

Also realize that if a crossing has a ‘crossing=traffic_signals’ then without a distinct ‘crossing:markings=’ it’s all but impossible to mark the signals and the marking as distinct items of the same way. At least without going super duper deep on mapping each and every pedestrian light as a node with directionality. I’d much rather have marked and crossing:markings as distinct because from a stress evaluations stand point how a crossing is marked is far less relevant than how it is marked.

Traffic Island is one item I have stronger opinions on as I really, really dislike the use of crossing:island=yes and believe traffic island need to always where possible be marked as either footway=traffic_island or cycleway=traffic_island. (I typically switch to cycleway for paths wider than 3m as these are wide enough for bikes to pass comfortably.)

Why the insistence on ways? I like to view bike-ped in a lens of stress and ways are far better at measuring this by looking at way lengths. For instance a crossing of a 6+ lane road with a traffic island in between is still crossing 3+ lane roads twice. The inverse is also true if a traffic island is below a certain length it can be very high stress if you only have a meter or less between two high speed roads crossing:island=yes can very deceptively make a path look low stress when it is in reality very, very high stress. So mapping these as ways when possible give so much deeper detail on good vs. bad routes and for those from the US this is much bigger factor.

I’ll also bring back up the bicycle=yes/designated question because while I understand the difference between countries in ‘expectation’ cycling apps that are global rarely have the appreciation for country by country nuance as I’d still say that consistency on bicycle=yes/designated is important. Which bicycle=designated indicated infrastructure designed with cycling in mind vs. bicycle=yes which is were cycling wasn’t designed but is permitted. Think ‘bike lane’ or ‘multi-use path’ = designated and ‘road lane’ or wider than usual sidewalk with no businesses = yes. I get in your context this nuance isn’t as significant a distinction but routers like Komoot, Strava, Mapy.cz, and other do treat these very differently so consistency is still helpful.

This actually isn’t what I think the wiki needs to be. This is the introduction to why we need more consistency and conversation around cycle mapping. The document I’m pulling from is 36 pages long, so loads more to come.