On 14 Nov 2009, at 18:05 , andrzej zaborowski wrote: > 2009/11/15 Apollinaris Schoell <ascho...@gmail.com>: >> matching Tiger id's is a very bad idea. you need to compare >> geometries. >> during edits ways are split, merged copied moved, deleted nodes >> added node, > > Most of these operations are not a problem (except copying a whole way > to somewhere else), the changed geometry is precisely what we want to > detect, so we can't use geometry for matching. >
copying is very common for all motorways and other ways with separated lanes. the worst example I have seen was a tiger way copied and used for a piece of coastline. merging is also a big problem because one of the tlid numbers will gone and the other extending in a different area. > I'm sure it has happened that mappers have incorrectly copied the ID > to some other way but I really hope that are isolated cases. You > claimed people were afraid to touch the Tiger tags. I agree with > Anthony that these tags are useless *except* this one tag, the Id *is* > useful, please don't remove it. yes many of them are useless, I was planning to ask Frederick to extend his bot when he is done with nodes. I think tlid should be kept for reference. some mappers like tiger:reviewed and this should be kept too. zip will be obsolete with address import. county can be derived from county boundaries. not sure about the meaning and usefulness of others Dave knows best why these tags are there and may shed some light on it. > > Cheers _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
