[talk-au] [OSM-talk] RFC: Tagging and rendering Australianhighwaynumbers

[Brent Easton]

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On 12/08/2007 at 12:43 PM Cameron Patrick  wrote:

>On Sun, Aug 12, 2007 at 07:06:32AM +1000, Brent Easton wrote:
>
>> Is this structure easy for you to parse and render?  No-one seems to
>> be complaining, I'd like to stick it up on th Oz tagging page soon.
>
>I like the tag values -but- I'm still not sure about ref:au vs ref
>(mainly from an editor support perspective) ... it seems to me that the
>fact that the road is in Australia should be quite clear from, well,
>the lat/lon.  It also doesn't match what's already been tagged.  It's
>tricky, though, because hacking in rendering support that varies by
>country is going to be an intrusive change to the renderer.  On the flip
>side, there have been occasional mentions on IRC about having rendering
>changed per country.

The problem is that we have no idea how long before our 'ref's would be rendered properly, or by what. Currently 'ref=' is rendered by Mapnik/Osmarender in a certain way and we don't really need or want to change that. What I need is a way to consistently tag routes now, that I know will eventually by rendered the correct way. 

In fact, by using ref:au, we are reinforcing the fact that it is a different tag to ref= and so has a differet syntax.


>So yeah, I've been staying out of the discussion because the actual tag
>values don't matter that much - they'd all need exactly the same kind of
>string matching in the renderer, which should be fairly easy to
>implement - so long as people are consistent in how it's used.  About my
>only comment is that prefixing numeric state routes with something (e.g.
>S-40 as in your scheme) is good from an easy implementation perspective,
>but bad from a "nothing is tagged like that" perspective.


When I started mapping, I had a look around and found state routes tagged various as 'Sn', 'S n', 'State n', 'State Route n'. As far as I can see, there is no rhyme or reason at all to what is there now, though it may be consistent in some areas by some mappers.

Does this scheme work for you:


ref:au=NR1     Highway 1 - (black on white shield)
ref:au=NH31    National Highway - (yellow on green shield)
ref:au=MR2     Metroad (blue on white hexagon)
ref:au=S151    State Route  (white on blue shield)
ref:au=T5      Tourist Route (white on brown Pentagon)
ref:au=A1      A Roads in states that have them (yellow on green rectangle)
ref:au=B2      B Roads in states that have them (yellow on green rectangle)
ref:au=C3      C Roads in states that have them (yellow on green rectangle)
ref:au=M4      Motorways(yellow on green rectangle)

This is probably better if it is just as easy to parse the letters from the numbers. 



>It's also just occurred to me that if some preprocessing was done in
>osm2pgsql (before mapnik got to see the ref tag) you could sort out just
>about any tagging scheme you wanted, perhaps including separating tags
>by country automatically.
>
>Cameron (chronic indecisive, probably not being very helpful - sorry)
>
>
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____________________________________________________________
Brent Easton                       
Analyst/Programmer                               
University of Western Sydney                                   
Email: b.easton at uws.edu.au