Rendering of railway=platform + public_transport=platform + light_rail=yes + area=yes

[jc86035]

Expected behavior

The platforms, given that they have the four tags, should render

Actual behavior

Platforms don't render at z19 (either a tile caching issue, or an issue with light_rail not being styled, or something about railway=platform)

Links and screenshots illustrating the problem

The platform

[Tomasz-W]

Duplicate of #435

[jc86035]

@Tomasz-W this is not the same issue; the issue is that railway=platform stopped rendering, and I don't know why it happened.

[kocio-pl]

That's because it has covered=yes tag, see #3162.

[kocio-pl]

Compare it also with other covered platform, which has a cover (building) tagged:

https://www.openstreetmap.org/way/220343050

[jc86035]

Are the platforms tagged incorrectly? They are entirely covered by a canopy but perhaps using shelter=yes instead would be appropriate.

[kocio-pl]

Interesting case. This was my design decision to hide covered platforms, because this usually means being under the roof and that makes clutter. Covered roads are treated like tunnels IIRC, so we treat the cover as something solid:

openstreetmap-carto/project.mml

Line 520 in 7fd7cd7

WHERE (tunnel = 'yes' OR tunnel = 'building_passage' OR covered = 'yes')

See also: https://wiki.openstreetmap.org/wiki/Key%3Acovered

[kocio-pl]

Probably covered=trees would be both accurate and rendering as expected.

[jc86035]

@kocio-pl Not a tree canopy, a metal one (although there are trees next to it). Should I remove the covered=yes tag from the 140 or so platforms which have the same sort of metal shelter?

[kocio-pl]

Oh, I see. I guess adding this shelter (looks like building=roof to me) is the right way.

[jc86035]

Should that tag be on the same way as the platform, or should a new area with the same nodes have that tag?

[kocio-pl]

I think new area, since it's probably not exactly the same shape.

[kocio-pl]

Another possibility is to use covered=partialin some cases:

https://taginfo.openstreetmap.org/tags/covered=partial

[jc86035]

Out of interest, is it possible in Mapnik to only render parts of a multipolygon? (For the case where an object is partly under a building, and the bits outside the building are separate ways without covered=yes, but the rest of the tags are on the relation. Platforms with a single ref=* cannot be split into multiple ways/areas, since the label should only be rendered once in the middle of the platform.)

[jc86035]

On second thought, it would be fairly difficult to render the label sensibly if the middle of the platform were invisible.