[OSM-talk] Keep Mapnik relevant
mikh43 at googlemail.com
Sat Jan 17 10:48:42 GMT 2009
Were you the only recipient? I must have hit the wrong button - will resend
From: Ed Loach [mailto:ed at loach.me.uk]
Sent: 15 January 2009 11:17
To: 'Mike Harris'
Subject: RE: [OSM-talk] Keep Mapnik relevant
Did you mean to Reply All, or was this just for me?
All the best
> -----Original Message-----
> From: Mike Harris [mailto:mikh43 at googlemail.com]
> Sent: 15 January 2009 10:49
> To: 'Ed Loach'
> Subject: RE: [OSM-talk] Keep Mapnik relevant
> I've been watching this thread for a while and add these
> 1. The 'railway' issues: Would a simple fix be to label 'abandoned
> by using a relation? They are effectively now a relation of type=route
> that may include ways that are now on the ground as e.g. a footway, a
> bridleway, a cycleway, etc. as well as ways that no longer exist. Only
> the last of these would need tagging - and here the tag would not, by
> definition, conflict with any other tag as the way is no longer there.
> This is also consistent with the general concept of mapping what is
> there on the ground - without losing the information regarding the
> route of an abandoned railway that might be of great interest to
> railway buffs.
> 2. The former shop / pub etc. issues: the use of abandoned:xxx= and
> former:xxx= tags may be helpful - but may they not sometimes rather
> There is also a risk of overuse. On the other hand, even from the
> point of view of "map what is there" there is a case, IMHO, for some
> tagging of "what is no longer there". Examples in my area are:
> A. A large school. The OS maps (even the latest digital
> edition) show it as
> a school covering a considerable area. Aerial photography (e.g.
> shows a demolition site. On the ground there is no trace of any
> buildings - just a park (appropriately "Phoenix Park") criss-crossed
> by footways and cycleways and allowing some very useful links to be
> made between streets on either side of the area that were clearly not
> links when they went right through the school buildings. All of this
> has happened in a very few years, witness the OS mapping. As an OSM
> user I would want to know that I can use these linking ways and to be
> reassured that the OS map is wrong and more out-of-date than OSM ...
> So a need to include the former:xxx= tag. OSM currently shows just the
> park, no footways or cycleways and no school. I couldn't tell in
> advance of visiting the site whether OSM had not yet added the school
> or whether the OS map was out of date.
> B. Tennis courts and football field. The boundaries are shown on the
> OS but not labelled. Yahoo aerial photography shows outlines but I
> couldn't say their status. OSM tags these features as sport= and
> disused=yes. Mapnik doesn't render them at all but osmarender shows
> them as if they were live and available facilities (ignores the
> disused=yes tag
> presumably) - so you
> don't know that you can't play sports there unless you go to the edit
> On this occasion, the disused= tag adds a third option to 'abandoned'
> and 'former'! It would be good either for the features not to be
> rendered or for them in either renderer or for them to be rendered in
> both renderers but distinguished as not being available for would-be
> tennis of football players!
> We do need to work some consistency into this area ... Who decides?
> How can the debate be structured to work towards consistency and
> Mike Harris
> -----Original Message-----
> From: Ed Loach [mailto:ed at loach.me.uk]
> Sent: 13 January 2009 23:45
> To: 'Andrew Chadwick (mailing lists)'; talk at openstreetmap.org
> Subject: Re: [OSM-talk] Keep Mapnik relevant
> > And later on, if the building
> > gets
> > used for something else, you could perhaps change it to:
> > shop=candy
> > name=Fred's Wine Gum Emporium
> > former:amenity=pub
> > former:name=The Blue Grape # or old_name
> > former=<date> # ugh, mabye not
> > Well, it appeals to the stupid, plodding, pattern-seeking
> part of my
> > brain, kinda.
> But it probably is too limited.
> A couple of examples that spring to mind. A building in Wolverhampton
> that was a cinema when my dad was young has since been things like a
> bank and a pound shop at various stages and I think is now a pub. How
> many former tags will you support?
> Similarly there was a shop in Oxford that was a cheese shop (Little
> Clarendon Street circa 1987) that was a childs toy or clothes shop (I
> which) the following year and I am sure is something else again now.
> And the Woolworths in Wolverhampton which until recently (I'm assuming
> it is now closed) was the "lower ground" version of the Woolworths I
> remember as a child which was about 4 floors tall in total. I believe
> Boots took over what used to be the Woolworths ground floor but I
> moved away almost a decade ago so my memories are a little rusted.
> There are shops near here that probably have a different business (or
> two) in them every year. If you're going to go with prefixes you'll
> want something like 20080101-20080606:name=Spring Fashions Limited and
> 20080607-20081231:name=Fireworks'R'Us (names made up).
> For now I'm mapping what is actually here. If something changes in
> reality I change it in OSM. If at some point in the future OSM
> supports historical mapping in some way then I may look at perhaps
> going to the effort of adding historical tags as well as updating the
> existing ones.
> Railways, which I
> think may have triggered this discussion (or may have cropped up
> recently on another related email
> list) are an interesting case. Abandoned railways are something that
> currently exist in places, until they are converted into footpaths or
> something else. This isn't as such historic mapping as mapping the
> bits of an abandoned railway that still exist. Disused pubs are
> something I'm in two minds about. In some cases the building is an
> obvious landmark which would be a useful PoI whether it opens or not.
> And whether it opens or not is something which would be useful
> additional information for anyone wanting to visit the place. But
> disused pubs where the sign has been removed and it has perhaps
> changed to residential use I don't feel should still be marked. A bit
> like "the old post office" or "old bakehouse" as properties
> surrounding an office I used to live were both residential properties
> (one of which was rented on behalf of Mark McGhee when he was managing
> Wolves, and we could see into his kitchen from our office).
> So I guess I'm in the map what exists now camp, until OSM has some
> better method of historical (or future - and I admit I've tagged a
> highway under
> construction) tagging.
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