On Jan 29, 2008 8:13 AM, Michael Collinson <[EMAIL PROTECTED]> wrote:
> At 06:57 PM 1/28/2008, Tom Chance wrote: > >Hello, > > > >I'm a bit confused about these tags: > > > >railway=viaduct > >bridge=yes > >cutting=yes > >embankment=yes > > > >I assume that 'viaduct' covers these sort of elevated rail lines so that > >bridges are just for, well, bridges over other ways: > > > http://www.mybrightonandhove.org.uk/images/uploaded/scaled/railway_viaduct_aerial.jpg > > > http://www.betterpublicbuildings.gov.uk/assets/images/finalists_2006/jamestown/jamestown_large.jpg > >http://www.24hourmuseum.org.uk/content/images/2005_1745.JPG > > > >Why is it not a property like bridge, cutting etc. and will it render > >correctly? Should it be changed to viaduct=yes? > > This is one of those "old" tags. Both bridges and viaducts were > originally nodes. I also think it reflects the earlier more > UK-centric tagging - "viaducts" are to the non-specialist those 19th > century long tall multi-arched stone bridges that grace many an > English valley and town. I ignore it entirely. Certainly if used, > viaduct=yes would make more sense. > > As to way forward, I suggest there are 3 options: > > - Depreciate the viaduct tag entirely [*] > > - Use viaduct=yes > > - Complement the generic bridge=yes tag and develop a specialist > bridge type tag for bridge devotees with precise > architectural/engineering definition. > >From what I think I understand, the railway lines out of Waterloo station in London are pretty much going to be classed as going over a viaduct all the way to Clapham Junction? These are raised manmade structures about the height of a house, mostly with arches etc. Same for lines coming out of London Bridge and most other London stations. In fact the district line (railway=>subway) between Parsons Green and East Putney is also viaduct? On that basis calling them a big long bridge doesn't really make much sense (we're talking at least several km/miles here), so we're probably best off with viaduct=>yes. Currently they're mostly just set at level=>1 without any specialist tagging for what they're going over, not even bridges over the roads. Dave
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