[OSM-talk] Administrative boundaries along roads

[John Smith]

On 22 March 2010 14:15, Anthony <osm at inbox.org> wrote:
> YOU said that I "meant re-use the road as part of a relation".  But in fact
> I did not.  My position on that is that sometimes that is a good idea.  And
> sometimes it isn't.  It's really case-dependent.  If a boundary is legally

And how would you know which ones are legally defined this way exactly?

> defined as the centerline of a road, then yes, I think you should use a
> single way, because if you fix one, you should fix the other.  On the other
> hand, if it is just a coincidence that the two lines are in the same
> position, you shouldn't use a single way.  In fact, in most such situations
> the lines wouldn't even coincide, they'd be off, if even by a centimeter or
> two.

Doesn't mean that people did that, they are most likely lazy and
copied the 2 ways and just had different attributes, again how would
you know the difference?

> While considering your points I did think of another situation, which is
> that a boundary is defined as the "current" centerline of a road (i.e. as of
> the time of adoption of the definition).  In that case I suppose it is best
> to use duplicate ways - one for the road and one for the boundary.  But even
> in that case you should *still* use a boundary relation.

What I'm suggesting is to keep boundaries and other objects separate,
even the relations, things get messy very fast, people start tagging
ways with admin attributes and vice versa and well you end up with a
pile of dung that is better separated than trying to merge it together
since you have no way to know with any certainity without a lot of
effort what the legal status is of the boundary.

> In any case, I don't think you've seen the mess created by the TIGER import
> of administrative boundaries.  This is especially true with regard to CDPs,

ABS has done something similar, at least in their case they only
produced boundaries and not ways as well, but the boundaries often
coincide with natural features, roads and railways etc and they've
been munged a lot by people not quite understanding the repercussions.