separate aeroways from rail/road query

[matkoniecz]

Currently there is a massive query that extracts data about rail, roads and aeroways.

Rail and roads need to be together to handle layering, but it should be possible to extract aeroways to separate query.

extracted from https://github.com/gravitystorm/openstreetmap-carto/pull/2168/files#r67127757

[matkoniecz]

It turns out that there is pecial rendering for aeroway bridges. Currently it is almost unnoticeable but open question is whatever it is something worth of spending time on it during solving this issue.

Below two examples:

https://cloud.githubusercontent.com/assets/899988/16170971/38284236-3564-11e6-9278-731a75ca79f7.png
https://cloud.githubusercontent.com/assets/899988/16170962/fe0006ca-3563-11e6-9359-b2d23a1f547d.png

[matkoniecz]

My opinion is that special rendering for aeroway bridges not worth extra complexity, especially as currently it exits only in theory.

[imagico]

A real life aeroway bridge exists on Madeira (though not tagged as such):

http://mc.bbbike.org/mc/?lon=-16.768059&lat=32.703393&zoom=16&num=3&mt0=bing-satellite&mt1=mapnik&mt2=google-satellite&marker=

The general question is if you render aeroways in a separate layer if this is supposed to be above or below the highway layer and how to distinguish between level crossings and bridges.

[matkoniecz]

There are:

• service roads reaching taxiways/runways (http://mc.bbbike.org/mc/?lon=12.211605&lat=51.42547&zoom=17&num=3&mt0=bing-satellite&mt1=mapnik&mt2=google-satellite&marker=)

• aeroway on bridge over road (Madera, Leipzig and others http://mc.bbbike.org/mc/?lon=12.211605&lat=51.42547&zoom=17&num=3&mt0=bing-satellite&mt1=mapnik&mt2=google-satellite&marker= http://mc.bbbike.org/mc/?lon=-16.768059&lat=32.703393&zoom=16&num=3&mt0=bing-satellite&mt1=mapnik&mt2=google-satellite&marker= )
• road/aeroway crossing (Gibraltar)

First one is common, second is rare, third one is extremely rare. I thought about rendering aeroways above road because it will work fine for the first and the second and will be acceptable for third one.

[imagico]

There is also service roads crossing taxiways:

http://www.openstreetmap.org/#map=17/50.03834/8.50779

which is quite common. I don't think level crossings in general are less common than bridges.

I have never heard of a bridge above a taxiway - the required clearance for larger planes would be quite large but this is not impossible.

This does not mean separating these features is not a good idea - just pointing out the circumstances.

[matkoniecz]

There is also service roads crossing taxiways:

I think that in such cases rendering taxiway above them also would make sense.

just pointing out the circumstances

And thanks for that, I dislike to be surprised by cases that I failed to predict. Especially during testing of final code version.

level crossings in general are less common than bridges

Level crossing of roads used solely to service airport are probably nothing atypical, but I would expect public roads crossing airport runway/taxiway (like in case of Gibraltar) to be really rare.

[imagico]

Regarding bridges above taxiways by the way i stand corrected - though not for roads:

http://www.openstreetmap.org/#map=17/39.85247/-104.67403
https://www.openstreetmap.org/#map=17/51.15731/-0.17739

[matkoniecz]

Are you sure? In Denver rail seems to be in the tunnel http://mc.bbbike.org/mc/?lon=-104.67459&lat=39.857181&zoom=16&num=3&mt0=bing-satellite&mt1=mapnik&mt2=google-satellite&marker=

Link for building in the second case: http://mc.bbbike.org/mc/?lon=-0.178098&lat=51.157438&zoom=17&num=3&mt0=bing-satellite&mt1=mapnik&mt2=google-satellite&marker=

[matthijsmelissen]

My opinion is that special rendering for aeroway bridges not worth extra complexity, especially as currently it exits only in theory.

Amsterdam airport has a taxiway on a bridge that is a quite significant landmark:
(at http://www.openstreetmap.org/#map=15/52.3279/4.7209)

[pnorman]

This has been done for road lines but should also be done for highway-area-fill and roads-text-ref

[imagico]

Apart from the case of bridges over taxiways there is another real world feature that exists (though rare) and that is incompatible with separating out the aeroways from the roads layers, that is underground aircraft hangars and the corresponding underground taxiways. These are rarely mapped since typically classified - only example i could find mapped is

https://www.openstreetmap.org/#map=16/44.8324/15.7531

We have of course never rendered aeroway tunnels so this is not removing an existing feature. But with the aeroways in the road layers we could add this while with them as a separate layer we cannot.