Add lane_markings field

[arch0345]

This PR adds a lane_markings field in moreFields for Living Street, Residential/Unclassified, Service, and Tertiary Road presets.

[tyrasd]

Living Street, Residential/Unclassified, Service, and Tertiary Road presets.

How did you come up with the list of presets for this new field?

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For context, here's an analysis showing the current usage of this tag in combination with different highway values:

highway=	total count	count with lane_markings	percentage
motorway	1,100,000	1,200	0.11 %
trunk	1,500,000	3,800	0.25 %
primary	3,200,000	17,400	0.54 %
secondary	4,600,000	42,700	0.93 %
tertiary	7,200,000	82,100	1.14 %
unclassified	15,000,000	96,000	0.64 %
residential	62,000,000	119,000	0.19 %
living_street	1,600,000	1,700	0.11 %
pedestrian	700,000	480	0.07 %
service	48,000,000	7,000	0.01 %
*_link	2,200,000	14,000	0.6 %
other (track, cycleway, construction, …)		1,000	< 0.01 %

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Especially the usage on the highway=service preset seems to be pretty rare. To me it seems that it would make sense to limit it to the range between unclassified and primary (i.e. everything with > 0.5% usage above) or alternatively, to simply include this field for all highway presets.

[bgo-eiu]

For what it's worth, part of why I haven't tagged lane_markings on many service roads is because I only recently learned of the key.

While lane markings are less common on service roads compared to other types of roads, that is a reason why it is useful to be to tag them where they do exist. Yesterday, I mapped a 4 lane service way contained entirely within a parking lot which had land markings, and forgot to add line_markings. It's common enough that I encounter it from time to time, but uncommon enough that it would be quite useful to be able to identify which service roads are like this.

[tyrasd]

For reference: currently, only 177 ways are tagged with highway=service + lane_markings=yes (the remaining 6.9k have lane_markings=no). I agree that the interesting cases would be the ones with the yes value. But I think these numbers are simply too low for the field to be also included in the Service Road preset. If the numbers change in the future, we can reconsider.

[bgo-eiu]

Alright, I didn't realize they were that low. I'll try to remember to use it more

[arch0345]

How did you come up with the list of presets for this new field?

I initially picked these presets since in my experience these lower classifications commonly have instances with both lane markings and without while higher classifications always have lane markings.

Looking at the current usage of highway=primary + lane_markings=no however, it looks like there are a considerable amount of roads of these higher classifications that don't have road markings.

I think these numbers are simply too low for the field to be also included in the Service Road preset. If the numbers change in the future, we can reconsider.

Alright, I'll add it to just primary-unclassified as you suggested for now. However, I think it should be kept on highway=residential because although it has a lower percentage tagged with lane_markings, it has way more roads tagged with it than the other road classifications.

[tordans]

Just as a +1, this sounds good to me.

I talked to @SupaplexOSM to hear his thoughts because he looked at this kind of data a lot for his detailed rendering (and mapping) of Neukölln, Berlin, Germany. For this area residential streets usually only have lane markings at the beginning of the street – if any. So it's good to have this tagging as "moreTags". It will show the details, but not mislead less experienced mappers to miss-tag the whole street. One example:

• https://strassenraumkarte.osm-berlin.org/?map=micromap#20/52.47928/13.44532
• https://www.openstreetmap.org/way/980711002#map=19/52.47929/13.44521