Mark these crossings on Norge i bilder imagery. 1 crossing, 1 image. Something like this:
I did this by hand, but I can do this programmatically. I believe I can make it so that the crossing (and therefore the marking) is always at the centre.
Go through the images, and select the ones where I can confidently say, crossing:markings should be zebra (such as the example above).
Screenshot from here. Tagging as crossing:markings=zebra seems more insightful than just a crossing:markings=yes.
Apart from the time necessary to complete this plan (especially step 4. could be time consuming - if it turns out to be not feasible I will consider using more powerful tools), what could go wrong? In other words:
Would the above described manual, yet still large-scale, tag edits have consequences I didn’t think of?
I think it would be easier to use JOSM and extract the undetermined crossing with this Overpass query:
highway=crossing -"crossing:markings"=* type:node in Oslo
Then walk through each case with the To-do plugin, using Norge i Bilder as the background imagery.
There are more than 30.000 crossings in Norway (6000 in Oslo) without any tagging for markings, so this is a very large manual task …
By the way, I believe crossings which are lacking crossing=* are even more important to tag because they determine right of way for pedestrians also in cases without markings.
Thank you, excellent suggestion! I made my first changeset regarding this issue. I wasn’t able to figure out how to use exactlly your query, but this seems to have worked:
[out:json][timeout:25];
area["name"="Oslo"]->.searchArea;
node["highway"="crossing"]["crossing:markings"!~"."](area.searchArea);
out body;
>;
out skel qt;
I am having some trouble regarding the To-do plugin though. This and this both say I should click Edit→Preferences, but I don’t have Preferences under Edit:
Very interesting, thank you. First, I would like to reach high level of expertise using non-AI based tools, and once I’m there, I’ll be happy to leverage these modern developments.
I think I grasped how the todo list works (see this changeset).
I think I quite got the hang of this. If there are any problems with this or this changeset, I’d appreciate if I was told about it. If no problems come up in a few days time, I’ll continue.
Most important: Make sure all crossings which you touch have a crossing=* tag. It should be crossing=uncontrolled unless it is already tagged as a traffic signal. 9 of your edits lacked crossing=*. You may search for highway=crossing -crossing=* modified type:node just before uploading.
Delete the crossing_ref=zebra tag. It is a duplicate of crossing:markings=* and it is not used in Norway anymore. Search for highway=crossing crossing_ref=* modified before uploading.
Add crossing:island=yes if you see a traffic island,.
I am slightly concerned about the first point: if I use crossing=uncontrolled for everything not tagged as a traffic signal, then I will probably tag crossings as uncontrolled which should have had a traffic signal tag but did not - isn’t this a problem?
In other words: am I not relying mistakenly on the traffic signal tags to be complete if the lack of them is a good enough reason to tag a crossing as uncontrolled?
All traffic signals have already been imported from NVDB, så I think it is quite safe to assume that the rest should be crossing=uncontrolled (if zebra markings are visible).
