[OSM-talk] Keep Mapnik relevant

Chris Hill chillly809 at yahoo.co.uk
Thu Jan 1 22:04:04 GMT 2009

Someoneelse wrote:
>> I notice that abandoned railways are now being rendered on Mapnik.  
> This was discussed a bit on talk-gb recently:
> http://lists.openstreetmap.org/pipermail/talk-gb/2008-December/003369.html 
> (and related messages)
> There are/were quite a few "railway=abandoned" features marked around 
> the Derby/Notts border in the UK.  Although many have been reused as 
> cycle tracks etc., many haven't, and of those that haven't there's 
> often nothing left visible on the ground at all.  In those cases I've 
> gone for "railway=dismantled", rather than just deleting the way 
> entirely, as it seems a shame to remove information that someone else 
> has added that isn't actually "wrong".
> Way 27144373 is an example - it's a section of the former Great 
> Central railway that runs more-or-less parallel with a former colliery 
> railway (the GCR was actually the later addition, but by the time of 
> the NPE mapping the colliery railway appears to have become disused).  
> A modern cycle trail follows much of the GCR, but not this bit (it 
> follows the older colliery railway).
> However, way 14837306 here:
> http://openstreetmap.org/?lat=53.19174&lon=-1.22413&zoom=15&layers=B000FTFT 
> shows a problem with this approach - Mapnik renders the name, but not 
> the actual way.  This is one where some sections probably justify 
> being left as "railway=abandoned", as there is more evidence on the 
> ground (although rendering it on a "standard map" is likely to cause 
> confusion).
Changing a tag from railway=abandoned to railway=dismantled just to stop 
it rendering is one of the no-nos in OSM: tagging for the renderer.  It 
would be much better to tag the line correctly and fix the renderer so 
they don't render on the Mapnik map.  Then a railway map or historic map 
could render it properly.

Cheers, Chris

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