[Tagging] [OSM-talk] Should we map things that do not exist?

[Stefan Tauner]

On Thu, 31 Dec 2020 18:14:44 +0100
Volker Schmidt <voschix at gmail.com> wrote:

> As I had pointed out in several contributions to this discussion, with
> support of some of the other participants, there can be good reasons to
> have such information in OSM, and there was no agreement that such bits in
> abandoned-railway routes should be removed from the database.
> 
> A similar discussion has been opened in the Italian list now, proposing the
> deletion of such pieces that are invisible on the ground.
> 
>  I just want to add a pointer here to a big (6k km) cycling project in the
> US <https://www.railstotrails.org> that is underlining my point that
> razed/dismantled/removed/disused railways do have a place in map data.

In half your posting you write about railways that are (perceived to
be) invisible and without traces. Then you write about
"razed/dismantled/removed/disused railways". I want to point out that
this is not the same. Clearly railways have a long-lasting effect on
the geography of a place that often remains in tact long after the main
elements like tracks are removed. It is obvious that these effects can
and should be mapped (e.g., man_made=embankment,
barrier=retaining_wall, historic=hollow_way - which needs a wiki
page/definition/new proposal BTW, cf. [1]).

However, I am not convinced that a completely razed railway has to be
tagged as such. Why would that be the case? If things are removed from
the world we delete them as well usually. Are there other man-made
features with long-lasting effects that get demolished (without
replacement)? (How) Do they get mapped? I have no example but I would
presume such things exist (that are not historic) like industrial
plants, mines etc. It might be more advantageous to improve tags that
describe the remaining effects than mapping non-existent things.

Without good replacements though I agree with your strong opposition of
removing that information from OSM.

> Have a god 

Certainly not! ;)

1: https://wiki.openstreetmap.org/wiki/Proposed_features/hollow_way
-- 
Kind regards/Mit freundlichen Grüßen, Stefan Tauner