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<div class="moz-cite-prefix">On 02.12.2022 13:31, Alex wrote:<br>
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<blockquote type="cite"
cite="mid:b07d6d0a-3178-af6e-0da0-60b729be72fa@riseup.net">
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Paths and ways along a road can be mapped separately in OSM, but
those separate geometries cannot be identified as part of the
road, or only with the significant effort of using geometric
processing (which most applications can't perform). </blockquote>
<br>
I strongly agree with the concept of tagging information that is
hard or impossible to compute accurately or reliably. I want to
emphasize that from the start since the objection has been raised in
multiple discussions that something is theoretically computable. I
would rather that we not obstruct valuable tagging because the same
information could theoretically be computed by some brilliant
algorithm not yet constructed and/or extremely detailed tagging,
that in combination would require significantly more effort than
just tagging the desired information in the first place.<br>
<br>
<blockquote type="cite"
cite="mid:b07d6d0a-3178-af6e-0da0-60b729be72fa@riseup.net">
<p> Therefore, a sidepath concept using the tag "is_sidepath" as
an additional tag on ways (in particular cycle ways or foot
paths) is proposed to indicate whether a way is
related/attendant to a road (i.e. adjacent and parallel to a
road) or whether it runs independently/isolated without any
relationship to a road. Furthermore, an extended set of sub-tags
is proposed to allow to explicitly tag important road attributes
on the sidepath itself.<br>
</p>
</blockquote>
<br>
<u>Mainly</u>, I have concerns about the concept of a cycle path or
foot path being attendant to or a sidepath of another road.<br>
<br>
In Norway, we no longer have cycle paths and foot paths. We have
cycleways, footways and carriageways. It may seem like a small
difference in terminology, but it makes a large difference as part
of an overall mindset. Roads are roads, and different types of roads
are simply meant for different types of travel.<br>
<br>
To me, this proposal sounds similar to a hypothetical proposal that
we start tagging roads that runs adjacent to railroads as
"is_sideroad=yes". It makes very little sense to me to establish the
railroad as the "primary" line of travel and the road as an
"attendant" line of travel. Just because they are parallel does not
mean there is a meaningful relation or hierarchy between them.<br>
<br>
I'm concerned that this type of tagging establishes and codifies a
hierarchy, a relative importance, and an
implied dependence, that I don't see in many of the posted examples,
and that I'm not aware exist in formal road structures.<br>
<br>
An exception of course is if the road was specifically built to
facilitate access to the railroad by non-rail means, and the road
was tagged as such, it would make sense to relate it to the railroad
it serves.<br>
<br>
I know the term "sidepath" exists and is used, but I can't see that
it is semantically different from cycle path, cycle road or
cycleway, except for this rather vague property of somehow being an
add-on to the "proper" road.<br>
<br>
Can you provide any thoughts on how you see the "is_sidepath"
relationship in principle?<br>
<br>
<u>Additionally</u>, I'm curious about what you will do with the
tag. I've read the use cases, but I don't fully understand them.
Perhaps you can elaborate?<br>
<br>
Rendering: How and why would a renderer treat a cycleway differently
when is_sidepath=yes?<br>
<br>
Routing: How does it help routers to know that a cycleway runs
parallel to a carriageway? If the preference is to ride on
cycleways, I assume the router will pick the cycleway regardless. If
there is no preference, I assume the router will pick whichever line
is shortest.<br>
I see a value in being able to capture a name.<br>
<br>
Data analysis: How is capturing the quality of a cycleway obstructed
by the lack of an is_sidepath tag?<br>
<br>
<u>Finally</u>, I agree that any use of is_sidepath or similar
conceptual tagging, like in the railroad access road scenario, seems
most valuable when it actually includes a direct reference to the
other line. Simply knowing that there is a line out there that is
parallel and adjacent to this line seems like very vague
information. Duplicating some information from the related line
seems a bit odd, because it still leaves no way to automatically
tell which line we're trying to reference. But I guess it can be
hard to implement a direct reference in practice, if the two ways
don't have exactly matching line segments?<br>
<br>
Cheers,<br>
<br>
Jens<br>
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