[EMAIL PROTECTED] wrote: >Sent: 28 January 2008 7:01 PM >To: Tom Chance >Cc: Talk Openstreetmap >Subject: Re: [OSM-talk] Bridges / viaducts for railways > >On Mon, Jan 28, 2008 at 05:57:24PM +0000, Tom Chance wrote: >> I'm a bit confused about these tags: >> >> railway=viaduct >> bridge=yes >> cutting=yes >> embankment=yes >> >> Why is it not a property like bridge, cutting etc. and will it render >> correctly? Should it be changed to viaduct=yes? > >Ewww, yuck... boolean flags. > >Personally I would tag as: > > railway=rail > bridge=viaduct >
bridge and viaduct are two separate types of structure so strictly speaking bridge=viaduct is incorrect. >for cutting I would have thought more like (this is a suggestion, there >is probably a better way): > > railway_level=-1 or railway_level=cutting > >and for embankment > > railway_level=1 or railway_level=embankment > We already use layer=+/-5 for setting display layering and I always envisaged the same simple system could be used for cuttings and embankments. >Map features has the really odd (IMO): > > railway=viaduct (node) > highway=viaduct (node) > I think these are legacy from when I first put up map features when we didn't have ways and all that and I wanted some method of showing a viaduct icon. Could be wrong. No harm in leaving this as the tag for a node though. >with the comment of something like "A high or long bridge...". "long" >and "node" don't go together as far as I am concerned ;-). You also don't >know what type of railway goes over the viaduct, as you lose the railway= >information. > >A possible, but slightly odd, example would be an underground train going >above ground and over a viaduct - it would be railway=subway, >bridge=viaduct. >If memory is correct, I think the DLR does that in some places in London >(railway=light_rail, bridge=viaduct)? > I'd prefer to see railway=rail for all rail corridors and a secondary tag for the type of service/stock used - ie metrorail/subway/underground/freight etc etc etc But it's no big deal to understand what's implied without extra tagging. Cheers Andy >Not sure what others do, though... > >Cheers, > >-- >Matthew > >_______________________________________________ >talk mailing list >[email protected] >http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
