On 12/13/2010 01:12 PM, Richard Mann wrote:
But this doesn't work well when you have lines that loop at the ends
(fairly common with bus services), because the two relations overlap
(you have to make certain nodes members in both relations, and that
starts crossing a complexity/maintainability threshold).
I see the problem with looping lines and I know several practical
examples. Even hafas sometimes can not handle this correctly and if then
this is usually solved that one stop is defined as the terminal stop.
The stops before belong to the route to the terminal stop, the others to
the route back. So in theory you have to change the bus at the terminal
stop, in practice this is not the case.
I think what we're edging towards is that expressing a tram stop as a
single node isn't really enough. I think the open question is how tram
stop pole nodes should be tagged, whether that affects
highway=bus_stop, and how you deal with joint bus and tram stops.
I support that one node for a 40m long tram stop isn't really enough.
My suggestion:
1) highway=bus_stop - nodes to mark bus stop poles and to be members
of bus relations (can also be used for tram relations)
2) highway=tram_stop - nodes to mark tram stop poles and to be members
of tram relations (can also be used for bus relations). Renderers may
prefer not to render these (there will generally be a
railway=tram_stop node to use instead). There are only 13 of these in
the world according to taginfo, so adoption of this tag for this
purpose is unlikely to annoy anyone too much.
3) railway=tram_stop - nodes to mark the centre of the tram stop area,
in the absence of a stop area relation. Mostly for rendering/labelling
purposes. Can be used as a member of uni-directional relations, if
setting up highway=tram_stop nodes is viewed as too complicated.
This is constructive. Thanks for that.
May I ask you some questions about that?
railway=tram_stop and railway=halt are mainly used for the stop position
of a tram/train. highway=bus_stop is the representation of the pole
(current schema).
Adding highway=tram_stop as the representation of the tram pole
eliminates the inconsistency between railway=tram_stop and
highway=bus_stop. What do you suggest for trains?
Here in Switzerland we have up to 470m long trains (German ICE), so we
have up to 470m long platforms with often two or more poles (or displays
as a replacement) per platform. Does it make sense to map all
poles/displays and to add them to the relation? Doesn't it make more
sense to replace the pole(s)/display(s) with the platform for relation
data to simplify things?
What do you suggest as the stop position for buses (as counterpart of
railway=tram_stop and railway=halt)? Or would you leave this completely
away?
Regards
Teddych
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