[OSM-talk] routing across open spaces

[David Murn]

On Wed, 2010-12-01 at 12:01 +1300, Robin Paulson wrote:

> > That's nonsense.  A way does not show a right of passage.  A
> > particularly tagged way shows a right of passage.  And a park is a
> > particularly tagged way.

No, a park *CAN BE* a particularly tagged way.  Just like a road, if it
isnt tagged properly with oneway/access/barrier/etc, the routing will be
inaccurate.

> this is all true guys, but it's getting away form the point: parks are
> only one implementation/manifestation of the situation. i'm enquiring
> about routing across areas in general, and whether anyone does/will do
> it.

One example of this, could be parking areas.  Shopping centres for
example have organised parking areas, with defined ways and spaces.
Other areas, for example a showground, might simply have a big dirt
parking area.  Or a playing field, which in suburban areas might be an
open field that you can walk across, but for a more formal field or
stadium, youre unlikely to be able to walk across.

> whether or not this is across a park is only a small (and possibly
> irrelevant) part of the issue. whether or not the area has been tagged
> correctly is only part of the issue

Actually, the fact that its not tagged correctly is a big part of the
issue.  The renderer has to make assumptions if its not tagged.  If
there was a tagging scheme to indicate that an area was traversable,
then routing engines could start to use it, but Id hate for a routing
engine to try and take a short cut 'as the crow flies' through an area
which hasnt got ways marked to follow.  To take that to a further level,
what if someone marked a national park as an area, should routers simply
show a route ATCF or should it only route through a national park area
if there is a way to follow?

David