[OSM-talk] Administrative boundaries along roads

[Anthony]

On Sun, Mar 21, 2010 at 10:24 PM, Mike N. <niceman at att.net> wrote:

>  In your point b), do you mean that if we did use boundary relations that
> there would not be an issue with boundaries and roads being co-mingled and
> mis-edited?
>

The use of boundary relations doesn't prevent people from mis-editing.  I'm
not sure what you mean by co-mingling, but I'm sure the use of boundary
relations doesn't prevent that either.

Are you familiar with boundary relations and how they work?  Anything you
can do with a single closed way you can do with a boundary relation.  So by
that fact any mistake or mess you can make with a single closed way can be
made with a boundary relation.

One of the biggest reasons to use boundary relations has nothing to do with
roads.  It's the fact that a border is generally shared by multiple
boundaries.  A single way can be used for a state border, a two different
county borders, a city border, and a township border, instead of having 5
duplicate ways (and that's not at all an unique type of situation - it's
something that happens all the time at state borders).

On Sun, Mar 21, 2010 at 10:28 PM, John Smith <deltafoxtrot256 at gmail.com>wrote:

> On 22 March 2010 12:24, Mike N. <niceman at att.net> wrote:
> > In your point b), do you mean that if we did use boundary relations that
> > there would not be an issue with boundaries and roads being co-mingled
> and
> > mis-edited?
>
> The problem with this is when boundaries or roads move independent of
> each other, such as for road-realignment, the whole thing becomes a
> bigger mess.
>

1) How so?  In the worst case scenario you have an equal-sized mess.  Can
you give an example?
2) In most cases of road-realignment you generally *want* to move the
boundary at the same time you move the road.  If a road centerline and a
boundary line exactly coincide, it's almost surely because the boundary line
is *legally defined* as the road centerline.  (If some of the lines
coincided by pure coincidence, then you can and should use duplicate lines,
but even that doesn't stop you from using a boundary relation.)
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