[OSM-talk] Display names of crossroads

[Andrew Errington]

On Fri, 15 Feb 2013 02:23:08 Jean-Marc Liotier wrote:
> On 02/14/2013 05:12 PM, Toby Murray wrote:
> > On Thu, Feb 14, 2013 at 9:37 AM, Martin Koppenhoefer
> >
> > <dieterdreist at gmail.com> wrote:
> >> 2013/2/14 Jean-Marc Liotier <jm at liotier.org>:
> >>> though I consider the everything=yes trend as namespace pollution. So :
> >>> - junction=* if there is enough diversity to justify that namespace
> >>> - highway=junction if junction=yes is going to represent most of the
> >>> junction=* space
> >>
> >> there is no risk that "yes" would be the most used value, currently
> >> more than 95% (or 266000) of the values are "roundabout".
> >>
> >> http://taginfo.openstreetmap.org/keys/junction#values
> >
> > junction=crossroads perhaps?
>
> Seems reasonable.
>
> So we would have at least...
> - junction=roundabout
> - junction=crossroads (unspecified crossroads)
>
> And a few more candidates...
> - junction=yield (to signify an uncontrolled crossroads where the lack
> of traffic signals in Openstreetmap is not mere neglect)
> - junction=stop (stop-controlled crossroads - which could be part of a
> relation linking the junction node with the positions of the actual stop
> signs)
> - junction=traffic_signals (which could be part of a relation linking
> the junction node with the positions of the actual traffic signals)

I disagree.  This is too complicated.

The problem is to specify that a junction has a name, and to disambiguate 
these from any other junction.

Right now we have a mechanism for this when the junction is a roundabout:
junction=roundabout
name=*

In the wiki is was stated that named junctions can be marked with:
junction=yes
name=*

However, Mapnik does not render a label for this.  I'm not sure if any other 
renderer does.  Mapnik *does* render a label for a named roundabout.

To add a junction name we could just add a name=* tag to the junction node, 
but then there is no hint about what the name means.  So, by adding 
junction=yes it indicates that this *is* a junction, and the name is the name 
of the junction.  It's simple and obvious.

junction=crossroads would be fine, but it doesn't add any information.
junction=yield is no good because it does not specify which direction of 
approach should yield.  junction=stop is also no good, for the same reason.

So, what I want is for Mapnik to render a label at a node if the there is a 
junction=yes tag (and name=* tag) present.  This has been stated in the wiki 
for a long time.

Thank you,

Andrew