[Tagging] Interpreting "One feature, one OSM-object"

Andrew Harvey andrew.harvey4 at gmail.com
Wed Sep 22 12:19:35 BST 2010

Quite a number of times I've noticed a single way having the tag
boundary=administrative (I assume having come from the Australian ABS
import and being part of a larger relation marking some town or
suburb) but also having waterway=stream (for example

My interpretation of the "One feature, one OSM-object" suggestion
would be that this is bad because the single way is being used for two
different purposes (representing a river, and representing an
administrative boundary). Because then you don't know which tags refer
to the river feature and which to the administrative boundary feature.

I would guess that the correct thing to do is have two different ways
which share the same nodes, one for the river and another for the
boundary. But I don't know how to duplicate an existing way like this
in JOSM.

If this is the agreed upon thing then it would be great if someone
could run a script that split the waterway tags from the boundary ones
into a new way. Having learnt from my last foray into running a
semi-automated script
I'll await feedback before rushing into writing one for this purpose.

It's not just rivers. For instance when I was adding an island, the
feature was already traced out as way
http://www.openstreetmap.org/browse/way/32317361 and then to seperate
the islet feature from the administrative boundary I added a new way
for this http://www.openstreetmap.org/browse/way/78499826. But I don't
know what's the best practice here.

This is really a general mapping question, not about the use of
specific tags so I'm not sure if tagging is the right list to post to,
but anyway.

More information about the Tagging mailing list