On Fri, May 29, 2009 at 12:23:03AM +0100, Thomas Wood wrote: > One concern I have (and one that's probably been expressed many times > on talk@ etc) is the use of disused=*, rather than adjusting the > 'primary' tag on the feature. (eg, railway=disused disused=light_rail > etc)
I think mixing the meaning of those two things is a bad idea. The concept of "disused" is orthogonal to the concept of "railway type". We don't write highway=oneway, oneway=primary. Mixing those concepts together might seem to make things easier, but in the long run it doesn't. Most software should just ignore everything that has disused=yes or construction=yes or planned=yes. (And yes, we need a definite list of all tags that need be ignore for this to work.) Worse is the assumption that there is a "primary" tag. There is no such thing, although it might seem that way sometimes. What an object is, is defined by all tags together, there is not necessarily a "primary" tag. We don't have a class with attributes, we only have tags. Look for instance at this example: A new bus platform is build. It gets the tags highway=footway (because it is part of a footway, too) and public_transport=platform. But its still under construction. Does it get tagged as highway=construction, construction=footway, public_transport=platform or highway=footway, public_transport=construction, construction=platform ? Both don't make sense, as it seems that only one aspect of this object is under construction. Using whatever=construction and construction=whatever_value is a bad idea, it links together concepts that can not be linked. This is a wider problem though than the public transport thing and it must be solved for all cases together. Jochen -- Jochen Topf [email protected] http://www.remote.org/jochen/ +49-721-388298 _______________________________________________ Talk-transit mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-transit
