[Talk-us] State Route relations (was: Highway TaggingConsensustoImprove OSM (and address some of 41 latitude's concerns))
niceman at att.net
Sat Oct 16 16:59:19 BST 2010
> The potential problem I see is when you have a road that alternates
> frequently between single- and dual-carriageways (which many state
> routes do, and even a lot of US highways). How do you represent this in
> a single relation?
> 1) Put single-carriageways in once, with no role. Or, with
> "role=north/south". Either way, this is difficult to recognize and
> parse automatically. And aren't members of a relation ordered inside
> the relation? (I know JOSM shows icons for whether a way is connected
> to the ways before and after it in a relation.) The ordering loses any
> meaning under this method.
The way I've done this, and seen it done, is to put single carriageways in
once with no role. I'm not sure I understand the difficulty of parsing
it automatically - please elaborate.
Ordering has no meaning in road route relations. JOSM can sort them as a
debugging tool. Ordering is too easily lost, as seen in the constant loss
of bicycle route relations sort order in Europe.
> In my view, having separate relations for each direction, and a
> super-relation to hold them solves this problem. But maybe there's some
> argument against them that I've missed.
It certainly will work also - my only complaint is juggling the 3
relations in the editor. Perhaps this won't be a problem after the road
network is comprehensively tagged.
More information about the Talk-us