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<p>I’ve
been on a campaign to get the accuracy of the Sustrans National
Cycle
Network improved for quite a while now and have made some progress
in
engaging with Sustrans.</p>
<p>I’ve found that the NCN plotted on OpenStreetMap differs in a
number of places from that in the Sustrans mapping.</p>
<p>I’ve created a coarse visualisation of the differences – see
<a
href="https://dent.org.uk/sustrans/sustrans-ncn-inconsistences/"
class="moz-txt-link-freetext">https://dent.org.uk/sustrans/sustrans-ncn-inconsistences/</a>
- which, by focusing on the thick red and blue areas shows which
areas to investigate in detail. Note this is a snapshot at Feb 23
and
won’t reflect any changes in OSM or Sustrans data until I update
it. Also note it is intended to show where to focus and some of
the
smaller focus areas may be errors in how I’ve done the mapping.</p>
<p>I know the Derbyshire NCN fairly well and have found that most of
the discrepancies are due to errors in the Sustrans data rather
than
OSM and suspect this may be the case across the country. </p>
<p>Sustrans have gone through a process of removing some of their
routes and “reclassifying” others (i.e. not being responsible for
them in the future). I’ve excluded these removed and reclassified
sections from the map and the comparison with the OSM even though
a
lot of the routes still appear in OSM as they still have signage
on
the ground. I’m taking advice on what to do about removed and
reclassified routes and will post a separate note on this subject
later.</p>
<p>I’m keen that Sustrans internally review the discrepancies and
make changes to their mapping when it is in error. I’ve had some
success in discussions but it is a slow process! There is
discussion
about involving the Sustrans volunteer force who are very
geographically spread and will have local knowledge.</p>
<p>I’m also keen to understand how best to communicate the
discrepancy areas to people within the OSM community with local
knowledge and who can, where the OSM is in error, make the
necessary
OSM changes.</p>
<p>Discrepancies are for various reasons including:</p>
<ul>
<li>
<p>mismatches on how the route is mapped (the map shows
differences of 10 metres or more).</p>
</li>
<li>
<p>Routes that Sustrans have classed as regional but OSM as
national (or vice versa). e.g. NCN 30 south of Lowestoft, NCN
568 on The Wirral</p>
</li>
<li>
<p>New Sustrans routes that haven’t yet reached OSM – e.g. NCN
28 east of Plymouth</p>
</li>
<li>
<p>Routes that Sustrans classes as “links” but OSM has as NCN –
e.g. NCN 28 near Dartmouth. I think these are generally
Sustrans errors.</p>
</li>
<li>
<p>Routes that OSM have included as NCN but which are not part
of the Sustrans network. e.g. NCN 627 north of Sheffield, NCN
422 near Wokingham</p>
</li>
<li>
<p>Some ferries are included as routes in OSM – e.g. NCN 2 near
Plymouth</p>
</li>
</ul>
<p>Sustrans data for the NCN can be found at
<a href="https://data-sustrans-uk.opendata.arcgis.com/"
class="moz-txt-link-freetext">https://data-sustrans-uk.opendata.arcgis.com/</a>
(Open Government Licence). Note that a lot of this isn’t accurate
so don’t take it as gospel – on the ground survey is needed.</p>
<p>I’ll continue to work with Sustrans to try and get their errors
improved. I’d appreciate advice on how to get the OSM community to
consider the discrepancies and fix any OSM errors found (local
knowledge needed).</p>
<p>Thanks to those who’ve already discussed this with me –
particularly the recent East Midlands OSM meeting.</p>
<p style="line-height: 100%; margin-bottom: 0cm">Ian<br>
</p>
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