[OSM-talk] Mapping everything as areas

[Roy Wallace]

On Sat, Nov 28, 2009 at 9:08 PM, Richard Bullock <rb357 at cantab.net> wrote:
>
> There's nothing stopping anyone mapping highways as areas.
>
> However, it could be a long time until routers and renderers catch up; the
> majority of the world wouldn't be able to position the areas accurately
> enough to make this worthwhile; GPS errors approaching the size of some
> roads; no suitable aerial imagery; lack of time to get the theodolite out
> everywhere...

I don't share your pessimism :P I just want to determine the best way
to do it, in case it turns out other mappers also want to contribute
in this way.

> In summary, I have no problem with people mapping everything as areas;
> however, I believe for the moment we will have to use both areas and ways.
> Most wide rivers mapped as areas I've seen also have a way down the
> centreline - to define the river name, and direction of flow.

That's interesting. I wonder if there are other examples of single
entities mapped as an area *as well as* a way? It seems this problem
may have been solved before?

> More importantly, using both ways and areas would render the way we'd expect;
> wider when zoomed out because the way is rendering wider than the area;
> wider when zoomed in because we are seeing the visible extent of the area,
> and we can have street names rendered in the right direction down the
> centreline. For routers we can continue to follow the ways as "navigation
> paths", ignoring areas, and we can define the direction of travel for
> one-way streets.

Yeah, these are good thoughts. But there's something that tells me
using an area AND a way for a single entity is a bit redundant... but
maybe you're right - maybe it's really quite good as (at least) an
interim solution.

I still think that, if using this solution, there are still some
uncertainties in terms of how to tag the areas/ways, and whether it's
necessary to indicate the relationship of the area & way with a
relation. I would imagine a relation would be useful to e.g. avoid tag
duplication on the area and way.