# [josm-dev] self-intersecting ways

Anthony osm at inbox.org
Fri Mar 26 13:39:51 GMT 2010

```On Fri, Mar 26, 2010 at 6:57 AM, Klaus Dietrich <kl-di at gmx.de> wrote:

> am 26.03.2010 01:41, schrieb Anthony:
> > On Thu, Mar 25, 2010 at 5:50 PM, Paul Johnson <baloo at ursamundi.org>
> wrote:
> >
> >> On Mon, 22 Mar 2010 01:50:23 -0400, Anthony wrote:
> >>> In OSM, the way which is tagged
> >>> highway represents the physical road, right?
> >>
> >> Centerlines, actually.
> >>
> > What centerline?  The actual painted centerline (surely not, it's not
> always
> > there, and it's not always in the center)?  The center of the physical
> >  The center of the lanes of travel?  The center of the right of way?
> >  Something else?
> I'm not sure what the correct english term is, maybe "axis", but in
> germany the relevent line is called "Straßenachse" or "Bauachse". See
> http://de.wikipedia.org/wiki/Achse_%28Verkehrsweg%29
>
> In my understanding, the way tagged highway represents the entire road
> including the shoulder and is defined by the "Bauachse".
>
> In my opinion this also means that as long as we don't use areas to map
> roads, the only correct approach for e.g. landuse next to the road is
> using the same nodes for both road and landuse. Because if the way
> tagged highway IS the road and the landuse extends UP TO the road there
> is no gap between them.
>

I understand what you're saying, and *if* the landuse extends up to the road
and there is no gap between them, I think you have a perfectly valid point:
to my mind, if that is the case neither situation is correct.  You can't get
the gap correct and the position correct simultaneously, without using an
area to map the road (what Frederik said).

Maybe for these situations we are best off using a landuse=highway area.
These areas could also be used in situations where the landuse for the
highway is greater than the road, but they would be required as an
alternative to connecting landuse areas to highway ways.

I had pretty much abandoned it (not because I think it's a bad idea, but
because I realized that the wiki isn't a very productive place), but see
http://wiki.openstreetmap.org/wiki/Proposed_features/highway

```