[Talk-ca] Problem with overpasses in NB??

Harald Kliems kliems at gmail.com
Tue Dec 3 23:04:50 UTC 2013

Okay, so I've done some digging. Unfortunately, the Overpass API does not
have a function to identify intersecting ways with a shared node. The only
way to find those would be do do an Overpass query for all the bridges and
then use javascript to identify the ways that share nodes. I lack the
skills to do the latter.

Identifying bridges which lack the layer tag, however, is easy:

Once all the missing layer tags will have been added, we can then use
keepright's (http://keepright.ipax.at/) layer conflicts function. Based on
the description of that function it actually seems like it should already
be able to find the problematic junctions:

"Connected ways should be on the same layer. Crossings on intermediate
nodes of ways on different layers are obviously wrong. Junctions on
end-nodes of ways on different layers are also deprecated, but common
practice. So you may ignore this part of the check and switch them off
separately. Please note that bridges are set to layer +1, and tunnels to
-1, anything else to layer 0 implicitly if no layer tag is present."


On Tue, Dec 3, 2013 at 9:21 AM, berniejconnors <berniejconnors at gmail.com>wrote:

> Here is another sample of the problem since Richard corrected my other
> example ;-)
> http://osm.org/go/cgOZhazjT?m=
> As I see it there are 2 problems with these bridges:
> 1) they intersect with the roads that pass beneath them
> 2) the layer value is not set so the default value of layer=0 (ground) is
> assumed. Typically a bridge should have layer=1.
> I would like to have an overpass api query that selects bridges that meet
> either of these conditions.
> Thanks,
> Bernie.
> Sent from Samsung Mobile
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> Talk-ca mailing list
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