[OSM-talk] zones for motorway/in town/outof town?

[Ben Laenen]

On Thursday 21 May 2009, Guenther Meyer wrote:
> > relations are one of only three basic structures in OSM (node - way
> > - relation), can we please assume that someone mapping with OSM can
> > grasp three concepts? He already should be able to deal with them
> > now anyway.
>
> they are, but at least for me relations really add some kind of
> complexity. yes, some things aren't possible with the other
> structures, but using relations as an answer for everything is not a
> good way...

I'm not proposing it for everything, I'm only proposing it for something 
where other structures have obvious setbacks.

But from some reason using relations for something else than routes is 
immediately regarded as some obfuscated mapping method.

> you have to get the whole relation, just to check, if some streets
> are part of it. size does matter here...
> with the tag-on-street approach you only need the street, nothing
> more.

The exact same argument would apply to store routes as tags on ways from 
now on. But that has its limitations, so we handle them with relations 
now. So this is another area where tags on ways are insufficient, so 
use relations instead. 

And it's an API limitation, which tries to handle relations just like 
ways. Relations are so different from ways that it just needs another 
method, yet for some reason that's not seen by the people creating the 
API. It's should be a method where each node, way or relation tells 
which relation it belongs to (without the need to download all member 
id's from that relation), and then there should be upload functions 
that just tell "add/delete node, way or relation X as member of 
relation Y".

Ben