Hi Aidan, yes that looks a lot better having the line stops as "stop_positions" rather than being stations! think it draws better on osm.org now too! Also I missed that the larger building Way 199669935 covered the station as a large area!
Finally nit picking, should they be the more specific railway:"stop_positions" rather than public_transport:"stop_positions" ? :-) Hi Derick thank you very much for such a comprehensive reply! Think i am finally starting to understand some of the ( different ) methods used to tag stations & that some of them may be the standard way of tagging things, that some of them are maybe used but not as the Wiki states and that maybe many are totally wrong ! I am not sure that two nodes really does make sense when both tagged as stations? Having two nodes makes sense for sure, but both tagged as stations? are they really just not different buildings, entrances, lines or platforms of the same station that are more than a small distance apart .. being two physically different building does not necessarily make them a separate station ? :-) The scheme outlined above looks a good one, although not nessisaly as per the wiki.. ( and not followed by the majority of stations in London where every one seems to have a unique pattern to it ) > AFAIK, the idea was as follows: > > station > ======= > > The whole area with buildings and platforms: > - area: > - railway=station > - area=yes > > - alt_name=Edgeware Road > - name=Edgware Road (Bakerloo) > - or: > - name=Hampstead Heath > > - network=London Overground > - naptan:ActoCode=9f8798 > ... > This looks good and seems ideal, tho is not quite per the wiki.. i think the wiki still prefers a single node tagged as a railway:"station" for the benefit of placing the name correctly ( and maybe for the simplification of all stations having a single Node ? maybe maybe not ) > station's building > ================== > > - area: > - building=station > or > > If there is no station area or building: > > - node: > - railway=station > - all the tags from "station" > This looks good too, tho not what's folowed, many single buildings are tagged as an entire railway=station with no area for stations it seems > platforms > ========= > > way (or area): railway=platform, ref=<nr> > > Where the train stops: > > - railway=halt (on the railway track itself as a node) > - name=Kilburn Park > - line=Bakerloo > - network=London Underground looks great .. tho still not quite sure of the difference between a "halt" and a "stop" a "stop_position" etc.. mostly seem to be used interchangeably and in reality interchangeably with a "platform" etc.. > station entrances > ================= > > - station building entrance: building=entrance > - tube: railway=subway_entrance, name="Exit <nr>", ref=<nr> This looks great.. but in most (/all) cases i have looked not followed; instead if there are multiple exits each is wrongly tagged as a station, and as often there is no single station visible in the real world (its all underground) there is then no single node for the station. > http://www.openstreetmap.org/?lat=51.555173&lon=-0.165321&zoom=20 Hampstead Heath looks excellently done from my now current understanding, with the area marked as a station ( tho i still think the wiki implies having a single node as the station :-) ) the platforms individually marked ( as platforms ) and the stops as railway:"halt" ( & "Kilburn High Road" looks similarly done and good) Thanks for everybody's advice & comment so far! James On 9 March 2013 14:30, Derick Rethans <o...@derickrethans.nl> wrote: > On Fri, 8 Mar 2013, James Churchman wrote: > >> I was originally attempting to get all the London Underground Tube >> stations and Rail stations from OSM ( london xml file ) >> >> The issues with the data I have had are : >> >> 1) Some stations are tagged as Nodes, some as Ways and some as Relations > > <snip> > >> 2) Stations tagged multiple times (this is a much bigger problem) ! >> >> Approximately 75 % of all London Underground Tube stations are tagged >> with a Node multiple times, the distribution looks like this: >> >> 0 times : e.g. London Bridge, this is only a Way there is no Node for >> either the Rail or Tube >> >> 1 single time : this is the rarest case and as far as I can see the correct >> case >> Borough, Farringdon, St James' Park, Westminister and a few others are >> the few single tagged Tube stations in London >> >> e.g Farringdon looks fine >> http://www.openstreetmap.org/edit?mlat=51.52056&mlon=-0.10504&zoom=18 >> its a single node of "railway" type "station" and has the two >> "networks" correctly attributed to it of "National Rail;London >> Underground". The only issue that i can see with Farringdon is as with >> many other tube stations it has a additional russian name "name:ru" of >> "Фаррингдон" > > What's wrong with names in different languages? > >> 2,3,4 or even more tages for the same station .. >> >> High Street Kensington : >> http://www.openstreetmap.org/edit?lat=51.5008&lon=-0.19269&zoom=19 has >> 4 tags .. each one joined to a rail line >> >> Piccadilly Circus >> http://www.openstreetmap.org/edit?lat=51.510003&lon=-0.134754&zoom=18 >> is tagged twice ( once under a different way ) >> >> Lambeth North is again tagged twice ( once under a way ) >> http://www.openstreetmap.org/edit?lat=51.499021&lon=-0.112524&zoom=18 >> >> Oxford Circus Tube Station is not taged at all. but instead the 4 >> exits are tagged singularly as type "railway" and "subway_entrance" .. >> http://www.openstreetmap.org/edit?lat=51.515258&lon=-0.141406&zoom=18 >> though they all do seem to be grouped into a Relation of >> "public_transport" "stop_area" >> Is this level of tagging required, and would an actual "station" tag >> in the centre of these 4 entrances simply denoting the station itself >> be better ? ---as it is no station at all is plotted on osm.org >> >> Green Park Tube Station is similar again with no tagged station but >> many tagged entrances >> https://maps.google.co.uk/maps?client=safari&oe=UTF-8&ie=UTF-8&q=green+park&fb=1&gl=uk&hq=green+park&cid=0,0,15806140768408957347&ei=8To6UcfADM-w7AbP_oHQCA&ved=0CKwBEPwSMAA >> http://www.openstreetmap.org/edit?lat=51.506934&lon=-0.142474&zoom=18 >> >> Waterloo Station is tagged once as a large area Way, and then 5 >> separate times as well as Nodes detonating a station >> http://www.openstreetmap.org/edit?lat=51.50246&lon=-0.11246&zoom=17 >> they are dotted all about the place, some on lower layers, some for >> one train line or another .. > > Some times it makes sense to have two nodes though, as for Edware Road > and f.e. Elephant and Castle there are really two stations (for > different lines) > >> 3 ) Also there is the issue of networks tagging .. >> Some stations are tagged as "London Underground" or "National Rail" as >> they should, but some that are both a dual are tagged with two nodes >> one for each rather that a single node of "National Rail;London >> Underground" for example. eg Kensington Olympia is tagged twice, once >> with "London Overground" and once with "National Rail;London >> Underground" > > Again, sometimes the stations are actually different. Such as West > Hampstead (http://osm.org/go/euuy930F7-) Each should exist, tagged with > the appropriate network. > >> So in conclusion the problems I have found with Rail and Tube stations are : >> a) Tagged as Ways, Nodes or Relations; sometimes all 3, sometimes just >> a Node, sometimes a building Way of type "station", but no Node. >> >> b) Duplicated stations: sometimes an identical tagging many many many >> times. Sometimes the Rail and the Tube are placed as separate stations >> when they should be combined, sometimes there is a Way and also a >> Node, sometimes there is a station for every Rail line/track that >> comes into the actual station >> >> c) Stations are not taged at all, but instead the exits are all tagged >> as an exit, that are sometimes grouped as a exit relation >> >> d) Inconsistant tagging eg some are "train_station" and others just "station" >> >> ( e) odd Russian names for many of the stations ) >> >> >> This is just from the ones I have looked at so far, I will look >> further in the mean time but asking from the OSM data the position of >> Rail and Tube stations in London is a very non-trivial task. Is there >> something missing from my understating, or does a refurbishment of the >> rail stations data for London needed? maybe something like every >> station is a single node placed at the approximate center, and then >> "exits" or station buildings are separately tagged and grouped into >> relations a long with the original point, and that a standard >> "station" and not the "railway_station" tag is chosen ? Also do these >> kinds of issues exist for other cities both around the uk and the data >> for the rest of the world, and is it limited to stations? >> >> Hope this has been helpful & can hopefully can get a discussion going >> about what i am missing and what might be able to be done to help! >> > > AFAIK, the idea was as follows: > > station > ======= > > The whole area with buildings and platforms: > - area: > - railway=station > - area=yes > > - alt_name=Edgeware Road > - name=Edgware Road (Bakerloo) > - or: > - name=Hampstead Heath > > - network=London Overground > - naptan:ActoCode=9f8798 > ... > > station's building > ================== > > - area: > - building=station > or > > If there is no station area or building: > > - node: > - railway=station > - all the tags from "station" > > platforms > ========= > > way (or area): railway=platform, ref=<nr> > > Where the train stops: > > - railway=halt (on the railway track itself as a node) > - name=Kilburn Park > - line=Bakerloo > - network=London Underground > > station entrances > ================= > > - station building entrance: building=entrance > - tube: railway=subway_entrance, name="Exit <nr>", ref=<nr> > > I might be incorrect, but I think this is what I've done where I could. > Fe: > http://osm.org/go/euuy8jAu4-- > http://www.openstreetmap.org/?lat=51.555173&lon=-0.165321&zoom=20 > > > -- > http://derickrethans.nl | http://xdebug.org > Like Xdebug? Consider a donation: http://xdebug.org/donate.php > twitter: @derickr and @xdebug > Posted with an email client that doesn't mangle email: alpine _______________________________________________ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
