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

[Serge Wroclawski]

On Sun, Apr 15, 2012 at 8:57 PM, James Ewen <ve6srv at gmail.com> wrote:

> My personal feeling is that if you're going to map landuse to the
> physical edge of the road, then you should create the road as a
> polygon to show the edge of the road sharing the edge of the landuse.

Roads as polygons is really poorly supported in OSM, and by poorly
supported, I mean that for the most part, they're not at all, and
should be avoided.

While you might be able to render them, the renderer already has
support for rendering road size based on road type- using areas will
mess that up. In addition, AFAIK, none of the routing engines in OSM
support roads as areas, so using them would be a problem for both
renderers and routers.



> How much detail do you really need to convey? I would agree with just
> making a large polygon that defines the full residential area, and
> layering the roads over top of it. Reusing the nodes defining a
> roadway as an edge of the land use polygon makes sense to me. It does
> make it harder to manipulate only one entity that is using the shared
> nodes, but that's a trade off that you have to deal with.

One of the problems with landuse is that it's such an oddly defined
term in the first place. I don't know what landuse actually means.
Does it relate to zoning or usage? There are edge cases such as the
one you point out, and there are mixed use lots/buildings, and other
exceptions.

I generally avoid landuse altogether, as it's nearly impossible to
verify, and I've never found a situation in which I needed to know
what the landuse was for an area I was in, or traveling to.

This, I think, is the best advice for landuse - don't use it.

- Serge