Re: [talk-au] Should a "trail" route relation be one-way?

[stevea]

I forgot to say earlier, so I add here and now:  on really huge routes like 
this — thousands of kilometers long — it makes it more manageable for humans 
(and OSM software like JOSM and other tools / end-use cases like renderers and 
routers) to break up the route into logical sub-components.

I'm thinking of examples I know in the USA, like Pacific Crest Trail or 
Appalachian Trail, where there are either "by state boundaries" kinds of 
"chunking," or designated by Trail Management (I think the PCT uses letters of 
the alphabet to denote segments).

For Munda Biddi, you may want to inquire whether something like this "chunking" 
of the whole trail into smaller segments is already going on "officially," and 
mimic that in OSM.  I will say that dealing with a single relation that 
contains thousands of elements (over 1500 things slow down and get unwieldy) 
are hard to deal with and do recall that there is a 2000-item limit for some 
data structures in OSM.  I don't recommend putting more than 2000 ways into any 
single relation under any circumstances.

I hope all this helps.


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Re: [talk-au] Adopting AU prefix in route network

[Dian Ågesson]

Hey Mark,

I asked on Discord and both the ref on ways and on relations are used by 
different data consumers. While newer consumers use the relation, many 
older ones will use the way.


I'd be in favour of keeping the old_ref tags where the value is known. 
In Melbourne, at least, there are a lot of old road signs that will be 
hanging around long after the conversion happens in the area.


Dian

On 2022-09-05 19:53, Mark Pulley wrote:

Just a question about when (if) we do this. In the past I've placed the 
network/ref tags on both the relation and on the individual ways. Do we 
need the route number details on the ways as well, or can these be 
deleted from the ways?


Also, do we still need the old_ref tags (e.g. old route numbers prior 
to conversion to alphanumeric routes)?


If we go ahead with this change, I've got some time in the next few 
weeks, so am willing to volunteer to work on this.


Mark P.


On 26 Aug 2022, at 8:00 pm, Dian Ågesson  wrote:

Hello all,

Following on from a previous discussion on the mailing list [1], I've 
put together guidelines that would allow us to implement AU: prefixes 
in our route network tags.


The content is here: 
https://wiki.openstreetmap.org/wiki/User:Diacritic/Proposed_Australian_Routes


I am looking for affirmation that this change is a good idea and 
should be implemented in Australia.


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[1] 
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Re: [talk-au] Should a "trail" route relation be one-way?

[stevea]

On Sep 5, 2022, at 5:25 PM, Ian Steer  wrote:
>> For the "north only" and "south only" segments, I would certainly keep both
>> of these "directional" segments in the one "main" relation, but tagged with
>> role tags:  usually "forward" if the direction of the way corresponds to the
>> direction of travel, 
>> JOSM's relation editor also pays
>> attention to forward and backward directional role tags, presenting them
>> (after a click of the sort button) in a visually clear way.  
> 
> I'm a bit confused here.  Are you saying that even if the ways are in the 
> correct direction (and even have oneway=yes), they should have a role in the 
> relation of "forward" ?  (I don't see forward and backward roles in the wiki?)

If you wish to keep the number of relations that describe a richly-flavored 
route (with north- and south-only segments, summer- and winter-only segments... 
you certainly DO have that here) to a minimum — and your "don't even suggest 4 
relations" indicates you DO wish to do that — then choosing to make the route 
"bidirectional" is the way to go.  I'd say most routes ARE bidirectional, 
whether their author knows this or calls them that or not, especially if there 
are NO "directional role tags" (forward or backward role tags on elements), 
which indicates the members are all "bidirectional" ways themselves.

That said, I'm sort of repeating higher-level aspects of route relation 
practices as outlined here [1].  An earlier section of that same wiki [2] 
describes the forward and backward role tags and how they would be used, for 
example, in this case.  (That wiki also describes how north, south, east, west 
CAN be used as role tags, and as I mentioned earlier, this is frowned upon by 
some, but the wiki notes this is only done in certain circumstances in New 
Zealand, Canada and USA).

So, yes:  I AM saying that making a bidirectional route as you (and I) are 
"heading towards" (as the method by which you implement this route in the 
"efficient" and "easier, with few(er) relations" way to do so, DOES include 
using forward (and possibly backward) role tags on those member elements of the 
relation upon which oneway travel must occur.  Reading the wiki is one thing, 
but you'll want to see other examples of routes that do this (bicycle routes 
are a kind of route where this frequently happens, and so these frequently have 
role tags if they are kept bidirectional).

The OTHER way to do this is to (begin to increase the number of relations it 
takes to FULLY describe the route/routes) make UNIDIRECTIONAL routes, which do 
not have ANY role tags, but are a "straight shot" in the given direction.  But 
you'll need at least two, one for north, one for south (or east and west, if 
those are the predominant directions).  Then, you tie together the two routes 
with a "super-relation," which is a relation containing at least two OTHER 
relations (of the same type).

Sorry if that's confusing; these are fairly complex topics, and you are out in 
the far reaches of the technical possibilities of a relational database (which 
is what OSM is) as we discuss relations, relations with members that contain 
role tags, and especially super-relations.  There are rules and conventions, 
right and wrong ways to do things (if you choose "this" vs. "that") and often, 
several "correct solution implementations."  I think that's true here, and I 
think you are expressing a preference to "keep low the number of relations."  
OK, that implies a bidirectional route (not unidirectional routeS tied together 
with a super-relation, that's three relations at least, though the 
super-relation, simply containing the two sub-relations where all the "work" 
gets done with many memberships, seldom changes once it is established).

So, get to know (from both wiki and real-life examples, I'd recommend both 
hiking and bicycle routes) how bidirectional routes are constructed.  There 
WILL be role tags (usually forward, possibly backward) on those segments which 
are "one-way in THIS direction only on THIS member way," but that's simply how 
these are uttered into OSM.  (Please use JOSM's relation editor to do this, 
again, my opinion as to "the best tool to use," otherwise if you use iD to 
build the relations and their role tags, you will drive yourself crazy.  Some 
iD editors will disagree with me there, that's fine with me).

But with hiking trails [3], there are all those ADDITIONAL roles ("main" is 
assumed if empty, but there are also alternative, excursion, approach, 
connection) which it sounds like for Munda Biddi, there may be some of these 
(like spurs to campsites would be "excursion" and maybe summer or winter 
"branches" would be "alternative").  So, you've got some homework to do about 
the best way to structure this route.  I don't want to seem hand-wavy, or like 
I'm punting on helping you, but what you're doing is pretty advanced "relation 
structuring design," and it could go a variety of ways for a variety 

Re: [talk-au] Should a "trail" route relation be one-way?

[Ian Steer]

> For the "north only" and "south only" segments, I would certainly keep both
> of these "directional" segments in the one "main" relation, but tagged with
> role tags:  usually "forward" if the direction of the way corresponds to the
> direction of travel, 
>  JOSM's relation editor also pays
> attention to forward and backward directional role tags, presenting them
> (after a click of the sort button) in a visually clear way.  

I'm a bit confused here.  Are you saying that even if the ways are in the 
correct direction (and even have oneway=yes), they should have a role in the 
relation of "forward" ?  (I don't see forward and backward roles in the wiki?)

> For the summer / winter routes, you may want to see if you can coax the
> opening_hours syntax to properly reflect the "time" that these are to be /
> should be used, and also do a rename

I think this is impractical because Parks & Wildlife divert the route depending 
on river levels, so it depends on the season.

> Thinking about this .. and coming from 'public transport' routes ...
> Use 2 relations
> One from 'x' to 'y' (and public transports uses keys 'from' and 'to')
> The other from 'y' to 'x'.
> So you'd have 2 Munda Biddi Trail route relations.. similar to the India
> Pacific train - one from Perth the other from Sydney.
> 
> This would make clear the north only and south only routes...

I am very reluctant to do this.  The main reason is that 95+% of the trail is 
bidirectional, and route changes occur many times per year.  This would mean 
having the edit two relations each time the route changes.  The other reason is 
that creating 2 relations would not solve the summer/winter route issue (and 
don't even suggest 4 relations )


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Re: [talk-au] Adopting AU prefix in route network

[Mark Pulley]

Just a question about when (if) we do this. In the past I’ve placed the 
network/ref tags on both the relation and on the individual ways. Do we need 
the route number details on the ways as well, or can these be deleted from the 
ways?

Also, do we still need the old_ref tags (e.g. old route numbers prior to 
conversion to alphanumeric routes)?

If we go ahead with this change, I’ve got some time in the next few weeks, so 
am willing to volunteer to work on this.

Mark P.

> On 26 Aug 2022, at 8:00 pm, Dian Ågesson  wrote:
> 
> Hello all,
> 
> 
> 
> Following on from a previous discussion on the mailing list 
> , 
> I've put together guidelines that would allow us to implement AU: prefixes in 
> our route network tags.
> 
> The content is here: 
> https://wiki.openstreetmap.org/wiki/User:Diacritic/Proposed_Australian_Routes 
> 
> I am looking for affirmation that this change is a good idea and should be 
> implemented in Australia.
> 
> Dian
> 
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Re: [talk-au] Should a "trail" route relation be one-way?

[Warin]

On 5/9/22 17:41, stevea wrote:

On Sep 5, 2022, at 12:23 AM, Warin <61sundow...@gmail.com> wrote:

Be careful with the automated tool .. you can end up with the route comprising 
some 'north bound' bits with some 'south bound bits'.

I'm not sure what you mean by "the automated tool," Warin.  I'm only suggesting to use 
JOSM's relation editor window's "sort" button.



Yes, those 'sort' buttons are automated tools ... and they don't always 
'get it right'.





Roles 'forwards' and 'backwards' refer to the direction of travel with respect 
to the direction of the way - not 'north', 'south' 'east nor 'west'.

Yes, I know.  I'm not sure whether Ian does, though thank you for pointing this out, as 
perhaps I wasn't clear.  My intention was to convey my methodology (which works well) and 
to inspire Ian to discover (using wiki, practice and experience) whether it might work 
for him.  Some Contributors DO add cardinal directions as role tags in relations, and 
that is NOT correct, let's be clear about that.  (Sometimes they do this as 
"placeholders" during route construction, but this is not recommended as it is 
confusing to other human editors as these role tags are encountered).



I'm guilty of adding 'constructional roles' to help me organize, 
understand and edit these kind of relations. I usually delete the roles 
.. sometime it takes a second try.





Route roles are...
See https://wiki.openstreetmap.org/wiki/Tag:route=hiking?uselang=en#Roles

Yes, specifically for HIKING routes, this wiki and these role tags are crucial 
resources to read and use where appropriate.  Ian, it is essential that you 
read, understand and apply this wiki as appropriate to the Munda Biddi route 
relations in OSM.



I'd use the same for bicycle and horse routes .. as that would make sense?


The one web render I use is 
https://mtb.waymarkedtrails.org/#route?id=5810814=relation=8.0/-33.4621/117.7741 



I think that uses the same tools for all the routes.





You may find that the renders of hiking/bicycle and horse routes will take no 
notice of 'forwards' and 'backwards'.

Right:  as the OP mentioned not "know(ing) enough about the potential consumers of route relation data..." it 
wasn't clear to me whether this included knowledge of humans as consumers or software like renderers and routers as 
consumers.  Some renderers have "weak" support for role tags, but again:  it is most important to get the 
data "OSM correct," not "pretty for a particular renderer" (or router).


Thinking about this .. and coming from 'public transport' routes ...

Use 2 relations

One from 'x' to 'y' (and public transports uses keys 'from' and 'to')

The other from 'y' to 'x'.

So you'd have 2 Munda Biddi Trail route relations.. similar to the India 
Pacific train - one from Perth the other from Sydney.

This would make clear the north only and south only routes...

Yes, I agree, this is another workable solution, thank you, Warin.


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Re: [talk-au] Should a "trail" route relation be one-way?

[stevea]

On Sep 5, 2022, at 12:23 AM, Warin <61sundow...@gmail.com> wrote:
> Be careful with the automated tool .. you can end up with the route 
> comprising some 'north bound' bits with some 'south bound bits'.

I'm not sure what you mean by "the automated tool," Warin.  I'm only suggesting 
to use JOSM's relation editor window's "sort" button.

> Roles 'forwards' and 'backwards' refer to the direction of travel with 
> respect to the direction of the way - not 'north', 'south' 'east nor 'west'.

Yes, I know.  I'm not sure whether Ian does, though thank you for pointing this 
out, as perhaps I wasn't clear.  My intention was to convey my methodology 
(which works well) and to inspire Ian to discover (using wiki, practice and 
experience) whether it might work for him.  Some Contributors DO add cardinal 
directions as role tags in relations, and that is NOT correct, let's be clear 
about that.  (Sometimes they do this as "placeholders" during route 
construction, but this is not recommended as it is confusing to other human 
editors as these role tags are encountered).

> Route roles are...
> See https://wiki.openstreetmap.org/wiki/Tag:route=hiking?uselang=en#Roles

Yes, specifically for HIKING routes, this wiki and these role tags are crucial 
resources to read and use where appropriate.  Ian, it is essential that you 
read, understand and apply this wiki as appropriate to the Munda Biddi route 
relations in OSM.

> You may find that the renders of hiking/bicycle and horse routes will take no 
> notice of 'forwards' and 'backwards'.

Right:  as the OP mentioned not "know(ing) enough about the potential consumers 
of route relation data..." it wasn't clear to me whether this included 
knowledge of humans as consumers or software like renderers and routers as 
consumers.  Some renderers have "weak" support for role tags, but again:  it is 
most important to get the data "OSM correct," not "pretty for a particular 
renderer" (or router).

> Thinking about this .. and coming from 'public transport' routes ...
> 
> Use 2 relations
> 
> One from 'x' to 'y' (and public transports uses keys 'from' and 'to')
> 
> The other from 'y' to 'x'.
> 
> So you'd have 2 Munda Biddi Trail route relations.. similar to the India 
> Pacific train - one from Perth the other from Sydney.
> 
> This would make clear the north only and south only routes...

Yes, I agree, this is another workable solution, thank you, Warin.
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Re: [talk-au] Should a "trail" route relation be one-way?

[Warin]

On 5/9/22 15:52, stevea wrote:

BTW, I very much recommend using JOSM as your preferred editor when editing relations, especially route 
relations.  IMO, the route relation editor in JOSM is superior to all others.  Don't forget to click the 
"sort relation" button as a last step in the relation editor window before you close it, that 
"neatens up" the elements so they connect with each other as best they can (the set of elements 
that are in the relation when you click it), and identifies any remaining gaps visually and readily.  JOSM's 
relation editor also pays attention to forward and backward directional role tags, presenting them (after a 
click of the sort button) in a visually clear way.  With practice, once you "get it," you won't go 
back to any other way of editing (especially route) relations!




Be careful with the automated tool .. you can end up with the route 
comprising some 'north bound' bits with some 'south bound bits'.



Roles 'forwards' and 'backwards' refer to the direction of travel with 
respect to the direction of the way - not 'north', 'south' 'east nor 
'west'.



Route roles are

'main'

'excursion'

'approach'

'connection'

'alternate'

See https://wiki.openstreetmap.org/wiki/Tag:route=hiking?uselang=en#Roles


You may find that the renders of hiking/bicycle and horse routes will 
take no notice of 'forwards' and 'backwards'.





Thinking about this .. and coming from 'public transport' routes ...

Use 2 relations

One from 'x' to 'y' (and public transports uses keys 'from' and 'to')

The other from 'y' to 'x'.

So you'd have 2 Munda Biddi Trail route relations.. similar to the India 
Pacific train - one from Perth the other from Sydney.


This would make clear the north only and south only routes...








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