[Talk-us] Separate relations for each direction of US & State highways.

Martijn van Exel martijnv at telenav.com
Fri Jan 10 22:39:24 UTC 2014

On Thu, Nov 21, 2013 at 1:27 AM, Chris Lawrence <lordsutch at gmail.com> wrote:
> For example: way X pointing east is marked in relation Y as "east"
> (presumably we could assume that "east" = forward and the opposite cardinal
> direction "west" is backward). User reverses way X. Now the relation role is
> potentially backward.  JOSM seems to understand at least north/south and
> east/west and offers to fix it (see
> http://josm.openstreetmap.de/browser/josm/trunk/src/org/openstreetmap/josm/corrector/ReverseWayTagCorrector.java);
> no idea if iD or Potlatch do.
> We'd also need to make the validation tools smarter to recognize lossage
> (for example, realizing that the route is unbroken only if the chain of role
> tags once you account for the directions of the underlying ways is
> monotonic),

Picking up on this old thread again. The status is now that iD
partially supports the cardinal directions when reversing a way (it
does not understand things like north:unsigned, not sure if that is
easy to fix)
JOSM understands 'north' as well as 'north:unsigned' (and the other
cardinal directions of course) when flipping a way and offers to
correctly fix the member role.

Relation sorting does not seem to take the member role into account in
JOSM, so that bit is not affected (or am I overlooking something?)

The relation graph column in the relation editor does not recognize
cardinal directions in the same way it recognizes forward / backward
(with the dotted line display).

The main thing I haven't looked into yet is the validation checks. Who
knows which validation checks are run on relations in JOSM and/or iD
to ensure 'unbroken-ness' and perhaps other things?
Martijn van Exel
OSM data specialist

More information about the Talk-us mailing list