[OSM-talk] surface=unpaved

[Asztalos Attila]

On 11-Jan-2011 15:51, Richard Mann wrote:
> On Tue, Jan 11, 2011 at 1:18 PM, Asztalos Attila
> <attila.asztalos at gmail.com>  wrote:
>> As far as I can tell neither the mapnik nor the osmarender basemap displays
>> surface information/modifiers (ie. if a tag like surface=unpaved or similar
>> is present).
> Is it public access, or is it owned privately? I ask because there is
> a strong correlation between public roads and decent maintenance where
> I come from. And as it happens, Mapnik does show access=private.
It's a fairly ordinary public road, yes. As I mentioned, I can fully 
appreciate how this sort of issue might not be widespread in more 
advanced regions of the world, but we're talking Eastern Europe in this 
instance - maintenance standards vary greatly depending on lots of 
factors, and yes, simple city streets might stay unpaved for ages (I'm 
not talking about the main streets obviously, nor say that this is the 
norm - just that it can and does happen here and there). It is not 
uncommon at all to have a public street - in a probably peripheral 
location and/or with a rather low traffic - otherwise part of the city, 
with houses on it, but without pavement (=gravel or just dirt) which one 
would rather avoid driving on, if only one could plainly see this fact.

> (the general problem with rendering surface is that there's a lot of
> values and you will find it very hard to render without always having
> to look for a key to tell you what the colour/shading means). Which is
> not to say that knowing which roads are cobbled wouldn't be handy
> sometimes (but I probably think of this as something you need to
> render for yourself (cue ad for Maperitive...))
>
> Richard
I certainly see the merit of the argument "the data is in there, nobody 
stops you from using it", but the fact is that even a lot of the other 
OSM-data-using map sites use the default mapnik and osmarender basemaps, 
using overlays only for their custom purposes - and lots of less-capable 
navigation software outright uses the OSM tiles, end of story. Using any 
of these unfortunately puts one in the unpleasant situation outlined 
above. I know about Maperitive, and I actually use it to see the map 
with localized, non-default names, but I can't use it for quick lookups 
(generates for ages) or navigation with my mobile - in everyday 
practice, de facto all I ever see is the good ole' default tileset.... :)

As for the rendering - I'm not sure I would care enough to discern all 
(or most) possible surface types; it would suffice to realize that a 
road suddenly loses the quality of being paved - "take that route at 
your own peril". This shouldn't be hard to implement, whether by hashing 
or darkening the road color, or other means, I think.

    - Max