[Tagging] Expressway=yes/no versus new tags "dual_carriageway=yes/no", "limited_access=", "grade_separated"=?

[Joseph Eisenberg]

> I think that the tag itself is a bad idea

Could you state why? The tag seems to have a clear use and meaning,
and it is verifiable.

Is the problem that it is redundant? Do you think database users
should preprocess the parallel ways to determine dual carriageway
status prior to rendering, routing, or data analysis?

> This fact should be clearly stated prominently on the wiki page
> Also the wording would need changing....

I agree, that is worth mentioning.

Please feel free to edit the page, no need to ask permission or
discuss it first if you find something that can be improved.  Or I can
do it if you don't have time...

> The expressway key is only very rarely used outside of the US, and there is no need for it outside the US.

I understand if you would prefer to add something like
"limited_access=yes/no" + "grade_separated=yes/no" instead.

If a highway=trunk is not defined as an expressway in a particular
country (e.g. in Britain, Spain, Indonesia, Australia...), there is a
benefit to having some other tag or tags that express how the road is
constructed.

On 2/20/20, Volker Schmidt <voschix at gmail.com> wrote:
> On Thu, 20 Feb 2020 at 01:41, Joseph Eisenberg <joseph.eisenberg at gmail.com>
> wrote:
>
>> I updated the Key:expressway page to have a global focus,
>>
>> I looked at this. The expressway key is only very rarely used outside of
> the US, and there is no need for it outside the US.
> It appears sporadically in the UK (some five roads in total)  and in France
> (many of these few occurrences are expressway=no on otherwise perfectly
> tagged ways)
>
> I would suggest to the contrary, i.e. to state on the wiki page clearly
> that this a US-specific tag, not to be used elsewhere.
>
> Volker
>