[Tagging] Clarification on the role link in route relations

[Minh Nguyen]

Vào lúc 05:59 2022-01-10, Richard Fairhurst đã viết:
> The explanation on the wiki page looks like someone who didn't 
> understand the role attempting to document it. (On the OSM wiki! I'm 
> shocked too! This has never happened before!)

Hehe, consider this a plug for peeking at the wiki's attic once in a while.

> Minh Nguyen wrote:
>  > At the current usage level, data consumers probably would be
>  > unable to depend on the "link" role for any practical purpose.
> 
> I do use it in cycle.travel's turn-by-turn directions code. If a route 
> is tagged as a "link" to the River Loire cycle route, then by definition 
> it's not the main trunk of the Loire cycle route. Therefore cycle.travel 
> won't say "Follow the Loire cycle route" when turning onto this way.

So cycle.travel uses the role in the sense that it doesn't use anything 
tagged with the role. If a given route has no "link" members despite the 
same kind of signage, it would make no difference to cycle.travel, correct?

I was supposing that there's unlikely to be a positive use case for the 
"link" role on route=road relations because that combination is 
relatively rare. It makes sense that this role had its origins in 
recreational route tagging. Does the approved "connection" role serve 
the purpose that "link" has been used for?

-- 
minh at nguyen.cincinnati.oh.us