[OSM-talk] open question about boundaries sharing nodes with ways or nodes

Frederik Ramm frederik at remote.org
Wed Oct 14 08:23:29 UTC 2015


Hi,

On 10/14/2015 09:49 AM, Badita Florin wrote:
> This way is a highway and at the same time is part of the relation of a
> boundary. This seems invalid since it merges two types of features on
> the same way instead of keeping a logical separation between two
> different things. Is this a valid way? What if the highway is modified ?
> since the highway is not a legal boundary and just happens to overlap
> the real boundary, so if the highway  is changed for any reason, it will
> modify the boundary along with it.

This is not automatically wrong. It is possible that boundaries are
actually defined by highways or other features (rivers, for example).

> So what's the valid thing to do here?

You'd have to research how the boundary is defined. If there is some
sort of legal definition that goes "the boundary has the following
geometry: from lat/lon A to lat/lon B to lat/lon C...", independent of
the river or highway, then it makes sense to have two different
geometries. But if the legal definition goes "the municipality of X
extends until the middle of the river Y" then it would be wrong to have
two different geometries in OSM.

(If this happens - if the boundary is defined by the river or the
highway - then you still have various options of modeling this, for
example having two ways share the same nodes, or putting the
river/highway into the boundary relation. The latter seems more commonly
used but both are valid.)

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"



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