[josm-dev] self-intersecting ways

[Marko Mäkelä]

On Fri, Mar 05, 2010 at 08:29:20AM +0100, Dirk Stöcker wrote:
> On Thu, 4 Mar 2010, Marko Mäkelä wrote:
> 
> >+1. Some days ago, I came across a mkgmap warning for a dead-end oneway
> >in a residential area that was riddled with landuse polygons that shared
> >points with ways. It was very hard to see that the oneway was not connected
> >to the road it was supposed to. I spent several minutes detaching the
> >landuses from the roads in the area.
> 
> From my point of view landuses either cross streets or are glued to
> streets. Until we introduce area style streets there is no other
> sensible way.
> 
> The method to leave a little space beside the road is broken by
> design and as geodesy is my profession I have the little advantage
> that map making is a part of my profession. Databases where one
> feature did not directly join with the next one cause and caused a
> lot trouble in GIS and will also cause in OSM (when we start to use
> the data for something else beside making a map).

Sometimes, ways are mapped as single lines.  Later, if the way is rebuilt
(or remapped) as dual one-way street, or a footway or cycleway is built
(or mapped) beside the street, the glued-to-street areas are causing
problems.  I found find it awkward to extend the landuse all the way
to the middle of a street, crossing a footway or cycleway, for example.
Having detached landuse areas makes it easier to draw fences and the like.

> When JOSM really warns in cases where areas in line features overlap
> at the borders, than that warning needs to be removed.

I believe that the validator plugin does.

	Marko