[OSM-dev] MAPNIK - proposal to drop rendering of underground railway lines

Andy Robinson Andy_J_Robinson at blueyonder.co.uk
Wed May 16 16:10:14 BST 2007

Robert (Jamie) Munro wrote:
>Sent: 16 May 2007 4:00 PM
>To: Nick Black
>Cc: Dev Openstreetmap
>Subject: Re: [OSM-dev] MAPNIK - proposal to drop rendering of underground
>railway lines
>Hash: SHA1
>Nick Black wrote:
>> I would like to stop Mapnik from rendering underground railway lines for
>> these reasons:
>> 1) They make the map look cluttered
>> 2) They are not helpful as a navigational or locational aid
>> 3) They impede the use of the map as a navigational aid
>> 4) They are very innacurate, non-geometrical approximations, derived
>> from the location of stations
>+1 to removing underground railway lines if you mean "railway lines that
>are under the ground" (or replacing them with light-dotted lines or
>- -1 to removing underground railway lines if you mean "railway lines that
>belong to 'London Underground', some of which run above ground (e.g. in
>the suburbs)"
>I think the problem may be that it is not obvious what railway=subway is
>supposed to mean. Does this mean that the railway is in a tunnel, or
>just that it is managed by "London Underground" or similar? Map features
>says "A passenger rail service running mostly underground."
>What do we tag normal (mainline) train lines that are in tunnels?
>What do we tag "London Underground" lines that are above ground? Should
>we add tunnel=no to these? Or should we not assume tunnel=yes for

Personally I think they are all railways, they all run on the same type of
track. Thus for consistency I would prefer to see tagging as follows:

tunnel=true/yes (for subterranean sections)
catenary=true/yes (for lines with overhead power)
live_rail=true/yes (for third rail type METRO systems - including London
underground lines)

If you want to describe the usage then you could also include
commuter=true/yes or mrt=true/yes(for Mass Rapid Transit systems like the

>Robert (Jamie) Munro
>P.s. would it be possible to use the right colours for underground
>lines, and move the parts that are actually under the ground to a
>transparent overlay? Or perhaps the overlay could have the colours, but
>without it, the overground parts just show as railway lines an normal.

Would be nice to see them in their designated LU colours but agree with
NickB that clutter on the map should be minimized.



Andy Robinson

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