[OSM-talk] Azimuth measurement

[moltonel 3x Combo]

On 09/04/2014, colliar <colliar4ever at aol.com> wrote:
> Please, read carefully, I only wrote "right" and not "right/left".

Why add a tag instead of reverting the way ? Care to give an example
of a cliff or retaining wall that require two semantically-meaningfull
way directions ?

If you're not adding "left" variants, it means that you expect the
data user to already know about the way direction convention.
Expecting that he also knows about the right/left tag convention is
putting additional (and unnecessary unless you can point to a
counter-example) burden on the data user.

> My hope is/was that left/right is more supported and maybe, to get rid
> of tags depending on way direction (like the above and guard_rail which
> I always have to look up).

There's both editors (warn during reverse and auto-change tags) and
data users (change rendering for example) to consider.
* Editors can potentially support the tag convention without
supporting the geometry convention, which is usefull when the editor
didn't know that a particular way had a meaningfull direction.
* Data users need to make a decision even if the left/right tag is
absent. So for them the geometry convention is necessary but the tag
convention is optional.

My wild guess is that for cases like cliffs where you could use either
convention, the geometry one will be better supported. For other cases
like cycle lane of course, only tags will work.