[OSM-talk] Divided roads proposal

[Steve Bennett]

On Fri, Dec 4, 2009 at 2:40 AM, Anthony <osm at inbox.org> wrote:
> I'm not sure how this would work without using areas, though.  And
> even then, it'll be complicated.  I think the proposal at
> http://wiki.openstreetmap.org/wiki/Proposed_features/Divided_road is
> far too kludgy and temporary

What do you find kludgy about it? I thought it was quite elegant? It
makes the division a property of the road, and lends itself to
assisting with routing.

>to justify going through the database and
> merging ways which were separated to represent roads with traffic
> islands.

I don't think anyone was proposing doing that. I mean, one *could* but
I don't see what the compulsion would be.

>  And doing so will likely lose data - specifically, the size
> of the divider (which varies often enough to make divider:width=* an
> insufficient solution).

Well, a couple of comments there:
1) Do you think the divider widths as currently recorded are
particularly accurate?
2) Do you think it's important?
3) Do you think in a situation where we had accurate information about
a non-uniform-width divided road, we would even consider throwing out
that information and replacing it with this? Of course not.

The point is, certainly in the areas I'm working in, there are lots of
back streets with median strips that are sketched out fairly quickly,
and there's nothing particularly interesting or important about the
width of that strip, and using two separate ways to indicate the lanes
on either side - *that's* the kludge. It's implying a higher level of
accuracy and detail than we have.

> The thing is, you kind of have to.  There has never been a one-to-one
> correspondence between "roads" and "ways".  It's not just dual
> carriageways that sometimes get rendered poorly, it happens when ways
> are split as well.

Yep, this proposal doesn't solve every problem.

> Mappers could assist the renderers by creating relations, so every
> single way which is part of Dale Mabry Highway (as in
> http://en.wikipedia.org/wiki/Dale_Mabry_Highway) gets put into a
> single relation.  I think that's more the way to go.  Solves lots of
> problems in addition to that one.

Yeah...but before that happens, the interface for editing relations
has to be really natural. And it would still be much more work than
simply marking a stretch of road. Better rendering is just one
benefit.

Steve