[OSM-newbies] How to draw land-use areas

[Steve Bennett]

On Tue, Apr 17, 2012 at 5:00 PM, Alan Mintz
<Alan_Mintz+OSM at earthlink.net> wrote:
> In my view, OSM's lack of support for roads (which are polygons, not
> lines) as polygons is a bug in dire need of fixing.Â
> Technically, everything is a polygon, since a line cannot exist in the
> physical world.

The line vs area debate is a perennial one and will not be solved any
time soon. Least of all on the newbies mailing list :)

In favour of lines:
- much easier routing
- much easier to re-use for many purposes: most of the time, the
information that people want about roads is essentially linear.
- easier to edit
- less information required to create and maintain
- better rendering at low zoom levels
- more flexible rendering (how would you render an area as a dashed line?)

In favour of areas:
- more precise
- allow calculations of other interesting kinds of information
- better representation of the "real world".
- less subjectivity
- better rendering at high zoom levels

This trade-off also comes up with rivers (riverbanks vs a line
representing the centre)...maybe other things too.

Me, I think the only real solution is a neat way to map both a line
and an area, simultaneously. Draw an area, and also a line, tag them
appropriately, and link between them. Then a renderer that can do a
good job of areas could ignore the line, and vice versa.

Steve