Hi Matthijs, hi everyone
It seems that a consensus hasn't been reached yet - at least not on this list.
The Swiss hiking network is a bit peculiar. It's not a typical node
network as the intersections (or nodes) aren't numbered and very often
are unnamed. On the other hand the hiking trails (not including the
routes from SchweizMobil) aren't typical routes as they are unnamed,
unnumbered, have countless possible starts and ends and often have
multiple variants from one named place to the next.
In my opinion, the simplest way to map the Swiss hiking trails is by
adding a tag to the corresponding paths (maybe trail=hiking or
hiking=designated) and using route=hiking routes only for the "real"
SchweizMobil routes.
Best regards
Raphael (dafadllyn)
On Mon, 23 Aug 2021 at 20:21, Matthijs Kooijman <matthijs@stdin.nl> wrote:
Hi all,
I'm new to this list, so let me start with a small introduction: I'm a Dutch
mapper, but I visit Switzerland every now and then (my brother lives in Rieden
SG) and I like to do some hiking and mapping here. In the Netherlands, I've
done some mapping on the cycle node networks, and in Switzerland I like to work
on the wanderwegen network (though I have not mapped much, so treat my input
accordingly).
I've been involved on the wiki page discussion section before, and from
the wiki page history found a link to this thread, which I have read
with much interest. Hopefully I can add something to the discussion in
this thread.
From reading this discussion, it seems that there are still some matters
where no consensus has been reached (in particular the matter of
overlapping or non-overlapping routes). But it also seems that there has
been some discussion about this off-list. Maybe some consensus has been
reached elsewhere?
In case you have not seen it yet: there has been some effort (initiated by
Peter Elderson AFAIU) to document current practices and rationale about node
networks. This is mostly based on the numbered cycle/walking networks in NL/BE,
but explicit effort has been made to also include named networks like Germany
and Switzerland uses. AFAIU there has already been some experiments involving
parts of the german network.
The current state of this documentation can be found here:
https://wiki.openstreetmap.org/wiki/Node_Networks
If this has not been done already, I would suggest considering to make the
Swiss tagging scheme either conform to that page, or modify/generalize that
page to also apply to the Swiss tagging.
I just read through the page, and here's some notable observations from the
current Swiss practice:
- The primary goal of the model specified is to facilitate routing and
rendering of node networks. For example, the knooppuntnet.nl website allows
entering a starting and ending node, and calculates a route between them
using only routes part of the network, and produces a list of node numbers
to follow (support for names instead of numbers is nearly complete, I
believe). For the Swiss case, this could work the same, but produce a list
of named nodes/guideposts the route passes (so you could walk the route
without bringing an actual map, just follow signs to each of the names in
turn).
- That page specifies to tag the actual junctions (as part of the ways they
connect), instead of (or in addition to) the physical guideposts (besides
the way they connect), which is a significant difference from the current
Swiss practice. I believe the goal is to simplify routing, since you can
then know which named junctions you pass exactly, without needing to find
guideposts based on nearness. It can also help with network consistency
checks (especially when combined with the expected_STn_route_relations
attribute).
- That page also talks about junctions without a number or name, and specifies
to create multiple partially overlapping routes in that case (and tagging
the unnamed nodes with `xxn_ref=*`).
Note that for the Dutch case, unnumbered junctions are very rare and almost
always in the near vicinity of a numbered node, so in the Swiss case in
regions that have more unnamed junctions, overlapping routes might have
additional downsides (such as a potential explosion of possible routes when
multiple unnamed guideposts exist between named routes, and the extra
difficulty mapping partial routes).
- That page specifies to use `name=from-to` for named node networks (numbered
networks use `ref=from-to`), while discussion on this list was moving
towards not using the name anymore. However, it might be that that page
specifies this to match current practice and could be changed without
problems.
- That page specifies a "network" relation (not strictly required, though),
that collects all the routes and nodes belonging to a specific node network,
to allow semantically grouping routes and specifying e.g. the operator once
for the entire network. In the Swiss case, I think this could amount to one
network relation for each Canton.
- That page specifies a `network:type=node_network` attribute for nodes,
routes and networks, to help distinguish them from regular routes.
Some earlier discussion about supporting named node networks has been done here:
https://github.com/vmarc/knooppuntnet/issues/102
https://wiki.openstreetmap.org/wiki/Proposed_features/Named_nodes_in_node_networks
Then, reading the wiki page in its current state, it seems to better reflect
current and intended practice, which is good. However, I think there are still
some things that could be clarified. In particular:
- How to tag unnamed guideposts? Common practice seems to be to just omit
name, maybe that should be explicit on the wiki?
- How to handle numbered guideposts? For example in Graubünden (I walked in
the area around Trin), I've seen guideposts (named and unnamed) that have a
three-digit number that were already mapped with the number in the `ref`
attribute, maybe that would be good to add to the wiki? For an example
(with photo) see: https://www.openstreetmap.org/node/6100531211 Similarly, I
understand that newer guideposts have a 6-digit unique number.
- Would it make sense to put these guideposts numbers in the relations?
Especially when using the "non-overlapping routes between junctions"
approach, putting these numbers in the from and to attributes could help
diagnose issues. OTOH, they are mostly meaningless to users, in the sense
that the signing does not point *to* these numbers, you can only see them
when you are at a particular guidepost.
- How to tag from/to with unnamed guideposts? Should we invent names?
Just omit the tag? I think no full consensus might have been reached
here?
- Maybe make explicit that name= was used with from-to before, since a
lot of existing routes still have that. If it is explicit that this is no
longer recommended, that will be less confusing for new mappers.
- Is it ok to copy routes from the cantonal GIS systems? If not, or
only from some, maybe make this explicit?
Gr.
Matthijs
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