[josm-dev] Reversing of node tags

[Frederik Ramm]

Hi,

Matthias Julius wrote:
> While looking a the code I noticed that JOSM is looking at all the way
> nodes for reversible tags.  Does it even make sense to have nodes with
> direction dependent tags?  I doubt that.  This is ambiguous when more
> than one way uses that node (and JOSM does not check for this when
> reversing the tags).

Hm. There is for example "highway=incline" and "highway=incline_steep", 
used more than 1600 times nodes in Germany alone. They usually come in 
tandem with "incline=xx%" which would have to be turned into 
"incline=-xx%" when the way is reversed.

You are right in saying that this is ambiguous in theory. In practice, 
of roughly 1650 occurrences in Germany, 1441 were used by only one way; 
167 were used by two ways (every case I checked was simply where one way 
ended and another began), and 34 were used by more than 2 ways (the most 
adventurous one being http://www.openstreetmap.org/browse/node/302422098 
but this looks like someone has misunderstood something). The remaining 
ones were not used by any way.

I don't even known if JOSM handles this correctly at the moment, but if 
it does then it should perhaps not be broken?

Bye
Frederik

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