[OSM-talk] Administrative boundaries along roads

[Anthony]

On Sun, Mar 21, 2010 at 11:59 PM, John Smith <deltafoxtrot256 at gmail.com>wrote:

> On 22 March 2010 13:53, Anthony <osm at inbox.org> wrote:
> > True.  What's your point?
>
> That you haven't actually done much work on boundaries to figure this
> all out for yourself and the pitfalls of some of the suggestions you
> are making...
>

What suggestions am I making?  I made a suggestion to delete the TIGER
boundaries, because they suck.  I also made a suggestion to use boundary
relations for administrative boundaries, because boundaries are generally
shared (with other boundaries).

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
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.

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.

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,
which coincide with absolutely nothing outside of what the census decided to
use for census purposes (but have names which are annoyingly similar to real
administrative areas which have completely different legal definitions).
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