man_made=bridge bridge=aqueduct combination.

[AllroadsNL]

The combination:

1. Is it possible to render man_made=bridge bridge=aqueduct below area natural=water? The problem showing the water of the aqueduct, it is now under the grey of man_made=bridge. What is not correct.

2. Is it possible to give man_made=bridge bridge=aqueduct a slightly darker color blue then natural water? (depends on 1. answer) So that the grey is not rendered.

Overpass man_made=bridge bridge=aqueduct combination.

[matkoniecz]

Can you give example of a correctly tagged area where it is a problem?

[AllroadsNL]

I updated the above example. The man_made=bridge bridge=aqueduct outline is wider then the natural=water area. These are two bridges (viaduct) and in the middle a aqueduct. I did not touch the underneath way, this is wrongly tagged, tunnel (they do it for the transparent way). (A other problem not to be discussed here).

The visual problem for much mappers is that the water seems to be narrowing, it is not, therefor the suggestion asked at point 1. This is the major question, can it be done?

[wysiwia]

Here is another sample https://www.openstreetmap.org/#map=17/52.23045/11.69692 Besides not showing the water on the bridge, the invisible roads below the bridge are shown as normal. Under the bridge they should be shown as underground objects or not at all.

[AllroadsNL]

Besides not showing the water on the bridge, the invisible roads below the bridge are shown as normal. Under the bridge they should be shown as underground objects or not at all.

As I mentioned before this should have it's own issue. made one #3491

We want to draw in more aqueducts in the Netherlands with man_made=bridge bridge=aqueduct, only because of the rendering people choose not to do it with man_made=bridge. Such a problem should be solved.

[jeisenbe]

The only way to solve this would be to give priority to the layer= tag for man_made=bridge and all water areas. However, water areas need to be rendered under the ocean polygons, and man_made=bridge needs to render above the ocean polygons (since there are bridges over oceans).

We could render man_made=bridge + bridge=aqueduct under water areas, but then any aqueduct that crosses over a river or another canal would be hidden.

We could render man_made=bridge + bridge=aqueduct as water, but I don't think that's what is intended.

In theory we could create a new layer like aqueduct-area just for water areas on top of man_made=bridge features, but I'm not aware of any existing tag which would define this area. The tag water=canal can be used for aqueducts, but most of these areas are going to be under highway bridges (the most common type of man_made=bridge feature).

So we would actually need to render all water=canal areas in the man_made=bridge layer and order by layer. This would have some performance impact.

Looking at these options, I am inclined to close this issue as "too hard to fix for a small improvement", but I would like to hear from other contributors. Perhaps there is an easier solution which I have missed?

[nc011]

A slightly simpler version of the same problem:

A canal (with the canal area added to OSM) is carried by an aqueduct over a river. The canal area has the following tags: natural = water water = canal layer = 1 bridge = aqueduct

The canal is being drawn on top of the bridge and the river but the canal area is not.

[pelderson]

jeisenbe wrote:

We could render man_made=bridge + bridge=aqueduct as water, but I don't think that's what is intended.

I think this could actually solve the problem for the water area part.

bridge=aqueduct would then have to be defined as only pertaining to the water-carrying area on the bridge, which I think is correct information and easy to understand for all mappers. The current side lines of the waterway on the aqueduct should preferably be suppressed if it is inside the bridge=aqueduct area. Instead, the bridge=aquaduct area could get the side lines. Other parts of the bridge could carry cycleways, roads, railways, footways etc; those parts can simply be mapped als adjacent bridges, not aqueducts.

[danieldegroot2]

Duplicate of #1608.