[Talk-us] City boundaries on the Canada/US border

[Paul Norman]

I started working my way across and the cleanup is progressing. I'm up to
monument 31 so far. Once I get out of populated areas it should go quicker.

The monuments are physically present on the ground, so their location could
be improved by more accurate surveys. However, I doubt if any consumer GPS
would be more accurate. The points agree with multiple sources of accurate
imagery within the resolution of the imagery.

I settled on ibc:ref for the turning points which don't have a survey_point
on the ground. Those refs help me keep track of where I am.

Starting in the water and going east, the border is now 
Delta-Whatcom County
Surrey-Whatcom County
White Rock-Whatcom County
Surrey-Whatcom County
Surrey-Blaine
Langley-Blaine
Langley-Whatcom County
Abbotsford-Whatcom County
Abbotsford-Sumas

> -----Original Message-----
> From: Toby Murray [mailto:toby.murray at gmail.com]
> Sent: Friday, March 30, 2012 7:51 AM
> To: talk-us at openstreetmap.org
> Subject: Re: [Talk-us] City boundaries on the Canada/US border
> 
> On Fri, Mar 30, 2012 at 7:18 AM, Alexander Roalter
> <alexander at roalter.it> wrote:
> > Am 30.03.2012 11:17, schrieb Paul Norman:
> >
> >> There are a significant number of cities in BC and Washington which
> >> have borders that in practice[1] coincide with the Canada/US border.
> >> Currently in OSM these are represented with many nearly-overlapping
> >> ways.
> >>
> >> The Canada/US border here consists of the BC-WA border, BC-ID border,
> >> BC-MT border, AB-MT border, SK-MT border, SK-ND border, etc. There
> >> are separate ways for the cities on the Canada side and cities on the
> >> US side.
> >>
> > ...
> >
> >>
> >> This would reduce the number of ways present when you download a
> >> section of the border and have many advantages. The one big
> >> disadvantage is that it would boost the number of ways in the Canada
> >> and US relations. This increases the chance of conflicts and also
> >> increases the number of places it could be broken.
> >
> >
> > I merged the us/canadian border with the north dakota, minnesota and
> montana
> > state borders and also county borders a while ago, and I agree that
> there
> > should only be one way for one part of the border, this line being
> shared in
> > all affected boundary relations.
> > I don't really think this will increase conflicts, as if you delete
> one way
> > of a border, all affected relations will be notified (at least in JOSM
> it's
> > impossible to download a way without downloading all relations this
> way is
> > connected.
> >
> > I did include city boundaries where available, but this was the case
> only on
> > one city (Emerson, MB). In Europe, nearly all borders are made up of
> > individual municipality border stretches (I once loaded italy's
> > circumference, made up of >2500 ways).
> 
> The problem with conflicts is if someone is splitting ways that are
> members of the US border relation down in Arizona while you are doing
> the same up in Washington. But in general I don't think this will be a
> huge problem. Much of the US border is either in water or sparsely
> populated areas where frequent edits are unlikely.
> 
> I've done some splitting of ways for counties along both the north and
> south border so I think this would be fine too. Overlapping ways are a
> pain to deal with. Then again relations can be a pain too :) But at
> least they are cleaner.
> 
> Toby
> 
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