[Tagging] [OSM-talk] Crossroad names

[Pieren]

On Tue, Apr 9, 2013 at 9:36 AM, Vladimir Vyskocil <
vladimir.vyskocil at gmail.com> wrote:

>
> Relation feature essentially means, "group up some objects to represent as
> a feature".
> So I think it could suite for our traffic_signal & junction naming,
> routing.
> (relation could express "label" membership)
>
> I also agree
>

I think we need some clean-up in the traffic signals tags/relations anyway.

>From its beginning, the tag "highway=traffic_signals" has been designated
to say "this intersection is controlled by traffic signals". It did not say
which lanes were controlled on which direction.  It was not intended to
identify each individual traffic signal.

Unfortunately, since we have hi-res images available, some contributors are
using the same tag to locate exactly each traffic signal next to the
intersection. Why not. We are not against improving data quality.

But the problem is that they use the same tag, most probably because it is
rendered and they just "draw a map". They don't care about the difference
"intersection controlled by traffic signals" vs "single traffic light".
They don't care if the same intersection is sometimes modeled with one
"highway=traffic_signals" or four or eight "highway=traffic_signals" nodes.
They don't care if it makes a difference for routing penalties or rendering
choices (e.g. zoom levels).

Once we decide to accept such level of details, we need to distinguish the
two methods of modeling traffic signals. We need a new tag to identify
single traffic signals . And we need of course a relation to say which
traffic signal belongs to which intersection (like for stops or giveway).
Once we have a correct modeling, it will be possible to use the data
correctly in applications like routing or rendering at different zoom
levels.
Note that we have intersections with names and intersections with traffic
signals. It does not have to be on the same relation types because it is
imho two different features.

Pieren
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