[Talk-GB] London Tube Tagging Problems

Fri Mar 8 23:49:08 UTC 2013

Hi Aidan, thanks for such a fast reply!

Yes very messy indeed!!
Great i had a good read of that link you sent along with
http://wiki.openstreetmap.org/wiki/Tag:railway%3Dstation and a few
others.

Reading :
---
* For simple modeling of simple stations with a single track (or one
in each direction) just add a node with railway=station and name=* at
an appropriate point on the railway (tagged railway=rail,
railway=subway etc).
* For complex or larger stations it is often best to create a node
within the main concourse area and use a public_transport=stop_area to
associate this with the rest of the elements of the station.
---

It sounds like uk tube stations that are largely underground the best
thing is just a node. For larger stations there should still be a node
but also but add it to a relation and additionally tag the Node as a
"Stop Area" and along with an Area for the building="station" .. but
the building="station" Area is not sufficient to be a station its
self.. it needs a node

Further down :
---
* There should only be a single railway=station tag for each station.
Where there are multiple nodes for a single station then consider
converting the station to the area format and moving the relevant tags
(including the name etc) to this area and remove the station tag from
all the existing 'station' nodes.
* Where a mainline station and metro station (or other railway like
station) are physically connected, consider if they should be modeled
as separate stations or as a single station. The associated Wikipedia
article for the facilities might assist with the decision. If the
facilities are run by separate organisations (for example a heritage
station next to a mainline station) then it is probably better to map
them using two separate railway=station tags.
---

So this would indicate that only one "station" tag should ever be used ..

Looking at your Kew Gardens tag it looks excellent with just one
issue. It's correctly tagged for all 3 networks in one as "National
Rail;London Underground;London Overground" but it does tag both stop
positions on the two oposite direction tracks as railway="station"
which i feel should both be changed to be railway="stop" or
public_transport="platform" and a new, single node should be
railway="station" for the entire station?

Think i am starting to understand how it should be done :-)

BR

James

On 8 March 2013 21:35, Aidan McGinley <aidmcgin+openstreetmap at gmail.com> wrote:
> 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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