[OSM-talk] Administrative boundaries along roads

[John Smith]

On 22 March 2010 13:31, Anthony <osm at inbox.org> wrote:
> 1) How so?  In the worst case scenario you have an equal-sized mess.  Can
> you give an example?

Because you are trying to hit a moving target...

> 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.)

While I don't know about the US specifically, it has happened in
Australia where boundaries that coincided with the centre of the road
weren't moved when the roadway was realigned.

On top of that you have boundaries of local governments change when
state governments redefine the local government boundaries, you have
boundaries of postcodes that change, are split or merged, road
alignment doesn't mean the boundary moves with it.

Just because some boundaries coincide with the centreline, doesn't
mean they are legally bound to the centreline...