<html>
<head>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<br>
<br>
<div class="moz-cite-prefix">On 25/01/16 11:58, Ian Sergeant wrote:<br>
</div>
<blockquote
cite="mid:CALDa4YKUhivKGxxJzFWXbrRmQ-tFPejN=qgcwxYQT9h0NHja9A@mail.gmail.com"
type="cite">
<div dir="ltr">Hi,
<div><br>
</div>
<div>
<div>The road is a vector, representing the road. It does not
represent the road centreline. It has properties, such as
width and lanes, and sidewalks.<br>
</div>
<div><br>
</div>
<div>If the boundary *is* the physical feature, then it is not
corrupting the data by making it align with the physical
feature. If the boundary is not the physical feature, then
don't align it.</div>
</div>
</div>
</blockquote>
<br>
How do you know it is the physical feature?<br>
<br>
Just because it follows approximately the feature does not mean it
is. When originally gazetted the physical feature may have been
located differently (roads, railways realigned, rivers making new
paths) Don't automatically assume that the feature is still in the
same place without looking at the imagery or physical survey. Don't
assume that the boundary changes to the new position of the road,
etc.<br>
<br>
<br>
<blockquote
cite="mid:CALDa4YKUhivKGxxJzFWXbrRmQ-tFPejN=qgcwxYQT9h0NHja9A@mail.gmail.com"
type="cite">
<div dir="ltr">
<div>
<div><br>
</div>
<div>The NSW/Victorian border has been done entirely along the
riverbank. Much of it by me and a few others after you guys
decided to take your bat & ball. So, I don't believe
this is actually an issue. Do you have any examples of
where this is a concern?</div>
<div><br>
</div>
</div>
</div>
</blockquote>
No. It was just an example of were an incorrect assumption had been
made.<br>
<br>
<blockquote
cite="mid:CALDa4YKUhivKGxxJzFWXbrRmQ-tFPejN=qgcwxYQT9h0NHja9A@mail.gmail.com"
type="cite">
<div dir="ltr">
<div>
<div>Tracing the actual border between NSW/Victorian border
was actually quite interesting. You have the gradual
accretion or divulsion to consider, and it is clear the LPI
data is not necessarily aligned with what is current. Most
of the border that I've traced I'd consider to be more
current than the LPI data, and I'd certainly want to thrash
it out before someone started replacing it with yet another
import. We've had so much ugliness in the past with these
imported data sets with no follow up.</div>
<div><br>
</div>
</div>
</div>
</blockquote>
But the border has not changed the river might have but there is no
change to the border from when it was first surveyed/gazetted. The
border is the line as when gazetted, not as where the riverbank is
now.<br>
<br>
An example of this is here:<br>
<br>
<a class="moz-txt-link-freetext" href="https://www.openstreetmap.org/#map=17/-36.19879/148.03658">https://www.openstreetmap.org/#map=17/-36.19879/148.03658</a><br>
<br>
Open it in josm then open the nsw imagery, and the nsw basemap and
you can see where the river was originally and where the border
runs.<br>
<br>
<br>
Cheers<br>
Ross<br>
<br>
<blockquote
cite="mid:CALDa4YKUhivKGxxJzFWXbrRmQ-tFPejN=qgcwxYQT9h0NHja9A@mail.gmail.com"
type="cite">
<div dir="ltr">
<div>
<div>This issue doesn't come up too much with property
boundaries - that are defined independent of the roads. It
does come up with rivers and coastline, and other areas
where the physical feature is what is the boundary.</div>
<div><br>
</div>
</div>
</div>
</blockquote>
Ian.<br>
<blockquote
cite="mid:CALDa4YKUhivKGxxJzFWXbrRmQ-tFPejN=qgcwxYQT9h0NHja9A@mail.gmail.com"
type="cite">
<div dir="ltr">
<div>
<div><br>
<div class="gmail_extra"><br>
<div class="gmail_quote">On 25 January 2016 at 11:09, Ross
<span dir="ltr"><<a moz-do-not-send="true"
href="mailto:info@4x4falcon.com" target="_blank">info@4x4falcon.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px
0px
0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF"> In Australia
all property boundaries are not the centreline of
the road there is always a road reserve as Andrew
pointed out. So simple do not make boundaries the
road.<br>
<br>
Likewise be very careful assuming the boundary is
the centreline of a river. eg the NSW Victoria
border along the Murray River. If you don't know
it's actually the southern river bank.<br>
<br>
Realistically with these boundaries if you move them
to align with any physical feature then you are
corrupting the data. Also if you make the boundary
part of a physical feature without checking the full
length of the boundary then you are corrupting the
data again.<br>
<br>
It's really much cleaner and easier to just
import/trace the boundary. If this shows up where a
road/railway/whatever should be then trace it from
the imagery as a separate way and tag it
appropriately.<br>
<br>
Cheers<br>
Ross
<div>
<div class="h5"><br>
<br>
<br>
<div>On 25/01/16 08:53, Ian Sergeant wrote:<br>
</div>
</div>
</div>
<blockquote type="cite">
<div>
<div class="h5">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote">On 25 January
2016 at 09:29, Andrew Davidson <span
dir="ltr"><<a
moz-do-not-send="true"
href="mailto:u887@internode.on.net"
target="_blank">u887@internode.on.net</a>></span>
wrote:<br>
<blockquote class="gmail_quote"
style="margin:0px 0px 0px
0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div> The boundaries of the parks and
forests are not going to be roads as
they consist of a number of property
lots that get declared for that
purpose. Property boundaries don't
run down the middle of the road,
they'll be offset (at times the
existing road isn't within the road
reserve anymore). Property
boundaries can be rivers (bank or
thalweg depending) or the MHWM (also
known as the "coast" in OSM). <br>
<br>
</div>
</blockquote>
<div><br>
</div>
<div>If OSM was only a colouring-in
exercise, then this would be
straightforward.</div>
<div><br>
</div>
<div>However, roads in OSM are a vector
representation of the road. And is is
very common for the boundary of an
area to be the road itself, that is
there is no small gap between the area
and the road.</div>
<div><br>
</div>
<div>When the boundary of an area *is*
the road, then I think it's entirely
correct to include the ways that make
up the road in the multi-poly that
defines the area. Even though the
vector nature of OSM slightly expands
features that are 2 dimensional when
they are adjacent to features that are
1 dimensional. The data is correct.</div>
<div><br>
</div>
<div>Of course, if the boundary isn't
defined by the road, but just happens
to be close to it, then that's
different.</div>
<div><br>
</div>
<div>Ian.</div>
</div>
</div>
</div>
<br>
<fieldset></fieldset>
<br>
</div>
</div>
<pre>_______________________________________________
Talk-au mailing list
<a moz-do-not-send="true" href="mailto:Talk-au@openstreetmap.org" target="_blank">Talk-au@openstreetmap.org</a>
<a moz-do-not-send="true" href="https://lists.openstreetmap.org/listinfo/talk-au" target="_blank">https://lists.openstreetmap.org/listinfo/talk-au</a>
</pre>
</blockquote>
<br>
</div>
<br>
_______________________________________________<br>
Talk-au mailing list<br>
<a moz-do-not-send="true"
href="mailto:Talk-au@openstreetmap.org">Talk-au@openstreetmap.org</a><br>
<a moz-do-not-send="true"
href="https://lists.openstreetmap.org/listinfo/talk-au"
rel="noreferrer" target="_blank">https://lists.openstreetmap.org/listinfo/talk-au</a><br>
<br>
</blockquote>
</div>
<br>
</div>
</div>
</div>
</div>
</blockquote>
<br>
</body>
</html>