[OSM-newbies] Fun with duplicate nodes

[Chris Mcnally]

I found a section in Brooklyn where the elevated railway has duplicate 
nodes where it passes over streets. I use JOSM and I think one node is 
for the street and another for the railway. I have two questions

1) I don't think i should join these nodes, i think both should be 
deleted so the street and the elevated train are not connected or 
intersected, is that correct?

2) how can I tell in JOSM that a node is part of a particular way, when 
I click on the dupes I cannot tell if it belongs to one or both ways.

http://www.openstreetmap.org/?lat=40.6794&lon=-73.95549&zoom=17&layers=B000FTF

I did find your changes in potlatch easy to use and it will help greatly 
to cleanup these dups.



Alan Mintz wrote:
> At 2010-02-10 02:11, Richard Fairhurst wrote:
>   
>> I've just added a bunch of dupe-fixing features to Potlatch. So when
>> you've used Matt's map to identify some dupes, click 'Edit in
>> Potlatch' and sign in as per usual...
>>     
>
> If I might inject a note of caution...
>
> It may not always be correct to join nodes that are in the same place. In 
> particular, I find it difficult to edit highways that share nodes with 
> landuse=* and boundary=* ways. There are many other situations that are 
> even more coincidental, where nodes that are used to approximate curves 
> happen to fall near other nodes that belong to an unrelated feature.
>
> One situation I see a lot where it _is_ useful is where a node exists on a 
> railway that is very close to a node on a highway that crosses it, and the 
> two should be merged into one node, tagged railway=level_crossing. Be 
> careful to look at the imagery, though, to verify that they actually 
> connect at-grade instead of one of them needing to be a bridge or tunnel.
>
>
> --
> Alan Mintz <Alan_Mintz+OSM at Earthlink.net>
>
>
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