[OSM-talk-be] sidewalk as ways or tags

[Renaud MICHEL]

On samedi 19 mars 2011 at 18:09, Ben Laenen wrote :
> Renaud MICHEL wrote:
> > He argues that the mapnik rendering of this show how irrationnal it is
> > (which is a personnal preference on which I differ) and that those
> > should be tagged on the main way.
> > I personnally think that it is more topologically correct, having a
> > parallel footway (where there exists ont) and foot=no on the main road,
> > as on important roads you may not cross anywhere, but only where a
> > crossing exists, so a separate way allow for correct routing for
> > pedestrians.
> 
> Can you show an example where this is the case, where you're not allowed
> to cross a road, but are allowed to walk on sidewalks next to it? I may
> have missed something, but I think the traffic code simply doesn't make
> it possible to have such a situation. Except when there really is a
> separate path next to the road, in which case the two just happen to be
> parallel and in which case drawing the footpaths as separate ways is the
> only logical option. And in which case you should really reconsider
> whether "footway" is the right designation.

You mean that a pedestrian is allowed to cross aven a national road anywhere 
he wants, and even walk on it?
I have always thought that (and acted acordingly), if a crossing (be it 
controlled or not) is close enough you may not cross the road but must take 
the crossing. (close enough beeing around 50-100m, but I don't remember 
exactly)

> Also, only put a tag like foot=no on the road when there are signs
> explicitly forbidding pedestrians on the road. Without such a sign, the
> road allows pedestrians walking along it (on the sidewalk or footway if
> there is one which is part of the road, or on the road itself
> otherwise), and crossing it anywhere they like, even if it would not be
> wise to do so. Because without the sign, pedestrians can still walk on
> the road if the sidewalk and verges happen to be blocked.

Well, my reasoning was that, as I had mapped separately the walking part, 
that the main road sould not be used for walking.

> > As an
> > example, on this way
> > http://www.openstreetmap.org/browse/way/57687924
> > you may simply not cross the road between the bridges.
> > (I don't create parallel footways for every road, only those where I
> > consider it unwise to cross anywhere)
> 
> "unwise" is a very subjective word. Tag the reality, nothing more.

Well, the sidewalks exists in reality, so I could map them all if I wanted 
to (which I don't, as you wrote previously it is useless for residential 
roads).

> That's a non-issue. These routers are getting better everyday. Don't
> start modifying data to help them do something now which they might do
> themselves tomorrow.
> 
> If you're really not allowed to cross a road, then the road is either a
> motorway, motorroad or has a sign forbidding access to pedestrians. And
> in these cases paths next to it are separate from the road and need
> their own ways.
> 
> We're of course still left with the issue of linking footways and
> cycleways to a road so a router can tell whether a pedestrian has to
> follow the path next to it (when these paths are part of the road) or
> not (when the path is a separate road itself), but then we probably
> enter the realm of the previous discussion on this list: street
> relations...

OK, I don't really understand your point about linking to a road, btu I will 
replace my highway=footways by footway=* on the main road where they are 
only sidewalks.
But that will probably mean splitting ways once more where sidewalks 
start/end.

thank you for your answer
-- 
Renaud Michel