[Talk-transit] Proposed Feature - RFC - Public Transport

Richard Mann richard.mann.westoxford at gmail.com
Mon Dec 13 12:12:15 GMT 2010


I think I may have figured out what it is that the established tags can't do.

If you've got a railway=tram with a series of nice neat (and
well-established) railway=tram_stop nodes then you can only make that
railway=tram_stop node a member of a route relation once. The oxomoa
conclusion was to have single-direction route relations.

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 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.

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.

Richard



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