[Tagging] Roles of route members (was: Merging tagging scheme on wiki pages of Hiking, ...)

[Paul Allen]

On Sun, 18 Aug 2019 at 10:01, Sarah Hoffmann <lonvia at denofr.de> wrote:

>
> I have no issue if relations require reasonable processing to get to a
> result
> but I would like to see enough information encoded in the route relation
> that
> the processing invariably gets me to the result that the mapper intended.
> I consider sorting and the use of roles essential for that.
>

So far we've only been talking of hiking/walking routes where some feel
sorting is
beneficial and others feel it is unnecessary.  At the risk of derailing the
thread,
there are other types of route relation.

Take bus routes.  I know of a very complicated bus route.  At three times
along the
route it drives into a cul-de-sac, reverses into a side-road of that
cul-de-sac, then
goes back the way it came.  Those three places are not termini, they are
merely
points along the route where most of the passengers remain on board.  In
one part of the route it does a loop-the-loop, going around four sides of a
square.
It traverses other segments of the route twice, in the same direction,
approximately
30 minutes apart.  Oh, and it does the reversing-turn trick in another
place that
isn't a cul-de-sac, it just doesn't go any further along that road.

It is perfectly possible to render the route.  Trying to figure out the
steps in the route
from the rendered route is pretty much impossible, although detailed
inspection of
the one-way markings eliminates several possibilities.  We don't (as far as
I know)
have any tool comparable to uMap that would allow ordinary users to step
through
the route so they can comprehend the details, although splitting the route
into sub-relations would allow uMap to give a crude approximation of that
capability.  But one day such a tool might appear, at which point having
the route
sorted would be beneficial.

Here is the route:
https://www.openstreetmap.org/relation/8592409#map=14/52.0860/-4.6643
Good luck figuring out where it goes, even though the list of ways is (I
think) correctly
sorted.  On the public transport layer you wouldn't even get the list of
ways unless you
queried the route.

So maybe sorting isn't absolutely necessary, but it can make life easier.
Maybe
we shouldn't ever insist that mappers sort the routes they add, but I don't
think
we should discourage them if they want to put in that effort.  Especially
if, one day,
somebody comes up with a step-by-step tool for displaying routes.

-- 
Paul
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