[Tagging] layer=-1, rivers, bridges and tunnels
ilpo.jarvinen at helsinki.fi
Fri Mar 14 23:24:07 UTC 2014
On Sat, 15 Mar 2014, Richard Z. wrote:
> On Sat, Mar 15, 2014 at 12:30:30AM +0200, Ilpo Järvinen wrote:
> > On Fri, 14 Mar 2014, Richard Z. wrote:
> > > On Fri, Mar 14, 2014 at 10:34:41PM +0200, Ilpo Järvinen wrote:
> > > > On Fri, 14 Mar 2014, Richard Z. wrote:
> > > >
> > > > > On Fri, Mar 14, 2014 at 04:51:18PM +0100, Pieren wrote:
> > > > > > On Fri, Mar 14, 2014 at 4:45 PM, Richard Z. <ricoz.osm at gmail.com> wrote:
> > > > >
> > > > > There has been a proposal long ago for bridges to have implicit an layer
> > > > > and it was not accepted.
> > > >
> > > > Was that for bridges being equal to layer=1 (which would obviously be bad
> > > > assumption) or for less than what layer tag can specify (e.g. +/-0.1 for
> > > > bridges/tunnels or whatever < 1)?
> > >
> > > https://wiki.openstreetmap.org/wiki/Proposed_features/default_layer_for_bridge_and_tunnel
> > Sadly the mapper point of view is almost totally missing from that
> > discussion. I've understood that is to most valuable resourse we've and
> > we should try to avoid putting any unnecessary burden on them.
> The proposal had the unfortunate side effect that it would have modified
> existing crossings in somehwat unpredictable ways.
> If it can be done without that side effect it may be possible.
It's true only if implicit layer equals to layer=1 but not if it would be
less than that.
> > Therefore, everyone needs now to handle those hardly useful layer
> > warnings about trivial cases (and waste their time on "correcting" them).
> even worse, people just apply layer=-1 to thousands of miles of rivers and
> similar tricks to hide those warnings.
Which proves my point. The mappers didn't like the unnecessary burden
nor the warnings which do in no way improve quality but only reduce
signal-to-noise of the validator.
> > And in fact, I've wasted some time just on that today while what I'm
> > really after is real geometry errors whose fixing would be much much more
> > benefial but JOSM validator did not differentiate these two cases for me
> > but follows such a bad spec.
> what kind of geometry problems?
JOSM validator reports them as:
"Crossing ways" ... many are real issues such as missing nodes or crazy
geometry in few of the ways (for variaous reasons: redaction bot,
accidential move in GUI, misclick too far away from one of the ways, etc.)
but sadly also these bridge/tunnel cases appear as noise in the error
(I needed to load lots of highways few weeks ago and I'm still
processing all those errors a got out from that as a side-product.)
More information about the Tagging