[OSM-talk] Divided/Non-Divided Intersection

Alan Mintz Alan_Mintz+OSM at Earthlink.Net
Mon Jul 12 11:35:32 BST 2010


At 2010-07-11 23:44, Maarten Deen wrote:
>On Sun, 11 Jul 2010 22:03:02 -0700, Alan Mintz
><Alan_Mintz+OSM at Earthlink.Net> wrote:
> > I like bringing everything together to a single intersection point
> > because that's what it (topo)logically is - a single intersection
> > controlled by a group of signals operating together (or stop signs
> > with drivers co-operating).
>
>I disagree with that view. A map is a representation of how it looks on
>the ground, not how the road is topologically made up.

I believe that is exactly backwards. A picture is used if you want to see 
what an area physically looks like. The style of map that is being rendered 
by Mapnik, OSMarender, etc. has always been a type of map (in a 
cartographic sense) that is a diagram of how roads and other mapped 
features connect with each other, using a defined set of symbols, 
linetypes, colors, etc. I suppose it could be argued that a topo map might 
blur this distinction, though it still uses symbology and lines to define 
the elevations instead of rendering the actual features.

It could be argued that splitting the roads into separate one-way ways is a 
hack for the purpose of convenience (usually to reduce the number of turn 
restrictions required).

I do think that this is an issue of personal style, and that most of the 
variations I've seen are reasonable.


>Or are you also removing bends and curves in roads because they have no
>topological meaning?

I remove very little. I draw bends and curves to make the map follow 
on-the-road GPS navigation, and to look nice. Yes, it's not a seamless 
intellectual framework for the universe :)

--
Alan Mintz <Alan_Mintz+OSM at Earthlink.net>





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