[Tagging] layer=-1, rivers, bridges and tunnels

[Richard Z.]

On Fri, Mar 14, 2014 at 04:36:26PM +0100, Pieren wrote:
> On Fri, Mar 14, 2014 at 4:15 PM, Jaakko Helleranta.com <jaakko at helleranta.com>
> 
> > At least OsmAnd renders all waterways with layer=-1 with
> > dashed casing, as if they were underground, which to me makes sense
> 
> That's clearly a bug. Waterways underground is specified by "tunnel=*"
> 
> > So, again : why tag things with with layer= tag when they are essentially on
> > ground level = not above or below other data (or at least natural objects
> > that might be mapped one day *) ? Am I missing something here?
> 
> Real case from real world : a deep ditch where the stream is not
> "underground" but below the "ground" level, is crossing a village
> where we have 10 bridges. Either you add 10 times "layer=1" on the
> bridges or you add 1 time "layer=-1" on the stream.

wiki says that every bridge should have a layer tag. If you are lazy
you can as well omit the layer altogether, it will be still rendered 
correctly.

Richard