OpenStreetMap
I was trying to add layer= attributes to the ramps in this (crazy) highway junction and later went back to check how it rendered and found that osmarender seems to draw the layer=-1 roads strangely when they hit the parkland underneath.
It draws the parkland over the top of the roads -- is that intended? What is the best practice for marking these roads and parkland? The roads are in a trench and the parkland is a whole area which is defined, i believe by law.
In general I suppose part of the question is how should trenches that aren't tunnels be marked. The area of land they're in doesn't cover the roadway, so I would expect it to be rendered like a regular road.
Discussion
Reäksje fan chillly op 31 maaie 2009 om 20.58 oere
The quirk seems to have disappeared now, but looking at the complex junction there are no bridge tags. I think these would help to make it clear which piece of road is above another.
A trench that carries a road or railway is known as a cutting and is tagged as cutting=yes. I'm not sure how it renders.
Reäksje fan stark op 2 juny 2009 om 10.34 oere
Yeah, sorry, I moved the points where the cutting started to not overlap the area.
Looking around i don't see bridge=yes being used for highway junctions generally. It seems unnecessary for people to understand the junction as long as the roads are labeled with layer= properly.
Actually I was wondering in a lot of places whether to use bridge=yes for the overpass or tunnel=yes for the underpass at intersections. I'm not sure which rendering I prefer.
Reäksje fan stark op 2 juny 2009 om 10.35 oere
And incidentally in this junction *all* the roads would be labeled with bridge=yes (excluding the roads in the cutting past the cliff)
Reäksje fan LivingWithDragons op 2 juny 2009 om 22.14 oere
I understand that everything is layer 0 by default, including the park. So you perhaps need to make the park layer -5.
If you do something that could be considered unusal (think by a beginner, not seeing everything so they could see a part of the park with no junction), then add a note to the way to explain why the tagging is as you've done.
Reäksje fan stark op 2 juny 2009 om 23.12 oere
This suggestion seems like solving a rendering bug by using tagging which is specifically forbidden.
I could understand if osmarenderer implicitly assumed either cutting=yes or tunnel=yes but it seems not having a road disappear entirely seems like a bug.
I suppose it's debatable. I can think of features that perhaps you would expect to completely hide lower level roads. Obviously higher level roads for instance. Perhaps buildings? But surely not natural=cliff?
Reäksje fan stark op 2 juny 2009 om 23.13 oere
We pretend there isn't a random extra "not" in that second paragraph.