[Talk-GB] London Tube Tagging Problems

[Aidan McGinley]

James,

Seems like a bit of a mess alright.  Take a look at the approved proposal
for public transport which should be the standard to work towards I would
think -
http://wiki.openstreetmap.org/wiki/Proposed_features/Public_Transport

I attempted to apply this to Kew Gardens station a while back (
http://www.openstreetmap.org/?lat=51.47707&lon=-0.28496&zoom=17)  it's not
exactly straightforward, and I'm not sure how well it would work when the
station is entirely underground like much of central London.

Aidan

On 8 March 2013 21:05, James Churchman <jameschurchman at gmail.com> wrote:

> Hi Guys
>
> 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
>
> London Bridge is large area Way:
> http://www.openstreetmap.org/edit?lat=51.50426&lon=-0.084887&zoom=18
> and is tagged as a "building" of type "station" and "railway" "station"
>
> Westminister Tube station is tagged as a Node
> http://www.openstreetmap.org/edit?lat=51.501144&lon=-0.125211&zoom=19
> of type "railway" "station" this possibly makes sense to be a Node as
> its too small to be a Way..
>
> Waterloo station is a Way
> http://www.openstreetmap.org/edit?lat=51.503282&lon=-0.113125&zoom=18
> but this time type "building" "station" ( rather than "train_station"
> as London bridge is ) ( and also "railway" "station" )
> but it's also grouped as a Relation of type "site" "railway_station"
>
>
>
> Maybe some being Nodes, Ways or Relations makes good sense, but maybe
> it does not... maybe all stations should be a Node ( London Bridge has
> no Nodes just a single Way ) and then station buildings should just be
> buildings.. that would at least be more consistant .. the buildings
> could always be put into a Relation with the Node if needed ?
>
> Also types of "train_station" and "station" etc... should this not be
> standardised?
>
>
> 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"
>
>
> 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 ..
>
>
> 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"
>
>
> 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!
>
> Best regards
>
> James
>
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