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

Andrew Errington erringtona at gmail.com
Wed Apr 2 06:32:34 UTC 2014

I have discovered a bunch of rivers and streams with layer=-1 in my
local area.  In my opinion this is simply wrong, so I am removing the
layer tag from the river and checking for objects which cross the
river (to tag them with layer=1.

Best wishes,


On 02/04/2014, Bryce Nesbitt <bryce2 at obviously.com> wrote:
> The present situation is that rivers implicitly render below highways in
> all common renderings.  That's not necessarily bad. With some formality to
> the layering arrangement, it sure would save a lot of tagging hassle and
> maintenance.
> The new cloud tag for example, is clearly to be rendered after everything
> but the celestial tags.
> Ahem.
> April 1st aside: the number of important implicit assumptions is relatively
> small.  Rivers under, power lines over, closed ways under except if they're
> tagged building, etc.  Currently this type of layering is implicit in
> various bits rendering software, but
> it could be formalized at the tag definition level to help meet certain
> mapper expectations.
> ---
> In the case of the river/highway layer warning: if the warning had never
> existed, chances are the various workaround schemes would never have come
> up.  Rivers would run under roadways, and tagging would be needed only in
> the rare case of a ford or an arroyo with no culvert.

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