On 22 Jun 2009, at 07:51, Jochen Topf wrote: > On Sun, Jun 21, 2009 at 05:09:35PM +0100, Richard Mann wrote: >> No, simpler than that: >> >> tracks=1 => render a single line at all zooms >> tracks=2 => render a double line at all zooms >> tracks=X => render a multiple line with X tracks at all zooms >> tracks=1ofX => render a single line at high zooms, but render as if >> tracks=X >> at medium/low zooms > > But then you'd still draw several lines nearly on top of each other > in medium > zoom levels which doesn't look good, which was the problem we were > trying to > fix? > > Anyway, this is a rather specialized trick about rendering the > number of tracks > properly. But what if you want to render other attributes. Say one > of your two > tracks is an industrial railway, the other a normal passenger > railway and you > want to distinguish those types. On medium zoom levels, is this a > two track > thing and we loose the type distinction, or do we keep it?
The dual_carriageway and Junction relations would appear to the a good way of doing such things. I realise that the 'dual carriageway' term is not right and that other work would be required on the specifications, however it would seem a better starting point. http://wiki.openstreetmap.org/wiki/Relations/Proposed/Junctions http://wiki.openstreetmap.org/wiki/Relations/Proposed/Dual_carriageways A group of parallel tracks would be combined using 'dual carriageway' and then a group short sections of track and nodes can be combined as a 'Junction'. The render would then have a choice of drawing modes, either a single line and single point, or multiple lines/points. Regards, Peter > > > Jochen > -- > Jochen Topf joc...@remote.org http://www.remote.org/jochen/ > +49-721-388298 > > > _______________________________________________ > Talk-transit mailing list > Talk-transit@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk-transit _______________________________________________ Talk-transit mailing list Talk-transit@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-transit