[OSM-talk] open question about boundaries sharing nodes with ways or nodes

[Christoph Hormann]

On Wednesday 14 October 2015, Colin Smale wrote:
> > A large fraction of 'authorative' sources of boundary data have
> > very little to do with the legal/contractual definition of the
> > boundary.  I would probably go as far as saying the most inaccurate
> > boundaries in OSM come from authorative sources.
>
> I would be interested in some supporting evidence for this...

OK - i need to constrict that - the most inaccurate boundaries in OSM 
are maritime boundaries which do not generally come from authorative 
sources.  The most inaccurate land boundaries are probably from 
non-authorative sources like CIA database and LSIB.

Without knowing the actual demarcation of a boundary this is generally 
difficult to assess and there are no boundaries imported from 
authorative sources around here but things like

http://www.openstreetmap.org/way/191851483

are likely inaccurate since nodes are placed away from the feature the 
boundary seems to follow and are located at positions that would not be 
well suited for demarcation.

> >> The boundary is where the government says it is...
> >
> > Not in OSM - see the 'on the ground rule'.  For OSM the boundary is
> > what locals treat as the boundary.
>
> That's a different boundary then. The area between the two might be
> "disputed", [...]

No, disputed is when people on one side of the boundary have a different 
idea of where the boundary is than those on the other side.

The general convention in OSM, also for boundaries, is to map the actual 
situation on the ground, that is which areas are actually administred 
by which authority.

-- 
Christoph Hormann
http://www.imagico.de/