[Tagging] sidewalk unsuitable for wheelchair

[Nick Bolten]

> Unfortunately, this breaks the semantic relationship between sidewalks
and the rest of the road ("this section of sidewalk belongs to that road
section"). Many applications do need that relationship, and it's pretty
much impossible to derive it automatically from separately mapped sidewalk
ways.

Absolutely, this is an open problem. However, there's no reason we can't
tag streets with `sidewalk=left/right/yes/no` to keep that question
answerable, while putting the pedestrian network itself (and its details)
on proper ways. In addition, the question, 'does this street have a
sidewalk?' is answerable for separate ways using geometric relationships,
even if a `sidewalk=* tag` were missing.

While not definitive, taginfo implies that `sidewalk=*` is used ~1.15
million times, while the subtags (like `sidewalk:right=*`) are used nearly
two orders if magnitude less often, and are mostly surface tags. I'm not
aware of anyone consuming that data outside of OSM2World, and would be
curious to know if anyone else is consuming `sidewalk:*=*`.

> A great thing about OSM is that a mapper adding data will normally
benefit all users of that data, even if they themselves are only motivated
by one of the possible use cases. But that doesn't work if the same tagging
scheme that enables one use case blocks or breaks another.

Absolutely. But I've personally not seen many users of `sidewalk=*` data
outside of some rendering, so it's hard to get a handle on what would break
by putting pedestrian network details on separate ways, where they are
immediately useful for routing + visualization.

Anyways, the OP has found a good answer for their issue, so I'll leave
further discussion to separate chains.

Best,

Nick

On Sun, Dec 10, 2017 at 12:20 PM Tobias Knerr <osm at tobias-knerr.de> wrote:

> On 10.12.2017 19:25, Nick Bolten wrote:
> > More or less, you describe sidewalks as `highway=footway`
> > `footway=sidewalk`
>
> Unfortunately, this breaks the semantic relationship between sidewalks
> and the rest of the road ("this section of sidewalk belongs to that road
> section"). Many applications do need that relationship, and it's pretty
> much impossible to derive it automatically from separately mapped
> sidewalk ways.
>
> A great thing about OSM is that a mapper adding data will normally
> benefit all users of that data, even if they themselves are only
> motivated by one of the possible use cases. But that doesn't work if the
> same tagging scheme that enables one use case blocks or breaks another.
>
> > For example, you
> > wouldn't have to make an executive decision about `sidewalk:width` vs
> > `width:sidewalk` - just use the widely-documented `width` tag.
>
> The format for sidewalk sub-tagging has already been documented in the
> wiki, so it's not really a decision that needs to be made on an
> individual basis:
>
> https://wiki.openstreetmap.org/wiki/Key:sidewalk#Additional_tags
>
> That section also already mentions wheelchair sub-tags which would solve
> Volker's problem:
>
> sidewalk:left:wheelchair = *
> sidewalk:right:wheelchair = *
> sidewalk:both:wheelchair = *
>
> _______________________________________________
> Tagging mailing list
> Tagging at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/tagging
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/tagging/attachments/20171211/90cb4a9a/attachment.html>