[Talk-GB] UK cycle route: NCN National Route 17 (21895) in Kent

[Dave F]

I've tweaked it a bit further using this XML/XSLT/XPath parser to search 
for gaps & spurious spurs:

Download the route relation as OSM/XML data
     curl -o NCN_17.osm -g 
https://overpass-api.de/api/interpreter?data=rel(id:21895);(._;>;);out;

Parse the data & output the results to file:
     java -jar C:\<Path to program>\SaxonHE9-7-0-2J\saxon9he.jar 
-s:NCN_17.osm -xsl:Route_Rel_Check.xsl -o:Route_Rel_Check_Upload.osm

The XSL routine that performs the parsing, Basically it takes the first 
node of each way & compares it with the end node of all the other 
ways.If it doesn't find a match it outputs the node's id.
The list of nodes starting with ' [not(@ref' are genuine end nodes to be 
ignored, such as the start/end nodes & where ways meet roundabouts 
mapped as a singular, circular way:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" 
version="2.0">
   <xsl:output omit-xml-declaration="yes" indent="yes" />
   <xsl:strip-space elements="*" />
   <xsl:template match="osm">
             <xsl:for-each-group select="way/nd[position() = (1, 
last())]" group-by="@ref">
                 <xsl:sequence select=".[not(current-group()[2])] 
[not(@ref ='26908253' or @ref='269810730' or @ref='30394554' or 
@ref='33118766' or @ref='30394555')]"/>
             </xsl:for-each-group>
   </xsl:template>
</xsl:stylesheet>

I've find this routine very useful to maintain cycle route relations in 
my area
Others may find this helpful all types of route relations.

DaveF

On 14/01/2022 15:46, Gregory Williams wrote:
> I've subsequently conversed with a Sustrans Volunteer Ranger that I
> know in the area and have cleared up the relation further. It should be
> looking better now.
>
> Gregory
>
> On Fri, 2022-01-14 at 08:28 +0000, Gregory Williams wrote:
>> I put some of that NCR17 mapping in. NCR17 has changed alignment over
>> time, but has also had issues with bad signing.
>>
>> I've removed some bits that I know are now wrong. I suspect that the
>> portion in west Maidstone around Poplar Grove to Queen's Road is also
>> wrong, but I think that there have been odd signs here that
>> incorrectly
>> suggest that it is NCR17. I seem to recall Maidstone having some
>> signs
>> that confused "17" and "(17)". I.e. is *on* vs. *leads to* NCR17.
>>
>> I've copied Maidstone Cycle Forum, as they should be know their patch
>> better than me! Perhaps they may be able to advise about the Medway
>> portion too?
>>
>> Gregory
>>
>> On Thu, 2022-01-13 at 13:28 +0000, Chris Hodges wrote:
>>> I'm not local so can't comment on that specific route, but it is
>>> plausible for a few reasons:
>>>
>>> - Some routes really do start and stop in silly places because land
>>> access negotiations have stalled. Sometimes in multiple places.
>>> NCN33
>>> in Somerset is like that, with work finally beginning on connecting
>>> it
>>> to NCN26 and Clevedon after over 10 years of proposals and talk.
>>>
>>> - Sustrans have been removing branding on (and support for) routes
>>> that
>>> don't fit their rather arbitrary standards.  This can leave gaps -
>>> or
>>> sections that have NCN numbers but aren't put of the NCN (according
>>> to
>>> their own map https://explore.osmaps.com/ncn hosted by OS which I
>>> used
>>> to use as part of my route planning but don't trust)
>>>
>>> - That same map doesn't always reflect reality as it ever happened,
>>> nor
>>> does it match the signs, which also don't match reality. We can and
>>> do
>>> make a better job of it in places.
>>>
>>> For example  NCN 45 into Bridgnorth from the north is correctly
>>> mapped
>>> on OSM (following the signs with a little interpolation where
>>> they're
>>> missing)
>>> https://www.openstreetmap.org/search?query=bridgnorth#map=14/52.5333/-2.4153&layers=C
>>>   
>>> but some odd sections that don't join up with anything are also
>>> mapped.
>>> They match Sustrans's own mapping, except that OSM is more sensible
>>> and
>>> doesn't show a route going across a school playing field, near but
>>> not
>>> following a public footpath. Some signs exist on those disconnected
>>> sections.  I think they had NCN route numbers on them when I was
>>> there,
>>> but I've also seen route numbers covered up
>>>
>>>
>>> A glance at Sustrans's map of the Maidstone area, without detailed
>>> inspection, suggests that much of what looks wrong could be right
>>> or
>>> at
>>> least official, but not all the disconnected sections match that
>>> map.
>>> But I wouldn't trust it to be right, as well as the obvious
>>> licensing
>>> block on the data, i.e. even if it was allowed, copying the
>>> "official"
>>> data would increase the errors
>>>
>>>
>>> Chris
>>>
>>>
>>> On 13/01/2022 11:24, Andy Townsend wrote:
>>>> This seems a bit odd:
>>>>
>>>> https://www.openstreetmap.org/relation/21895
>>>>
>>>> shows a couple of disconnected sections around Maidstone and an
>>>> odd
>>>> spur towards Chatham.
>>>>
>>>> https://osm.mapki.com/history/relation/21895
>>>>
>>>> suggests that at least one of the Maidstone "extras" has been
>>>> there
>>>> since 2008, suggesting that it's not a recent faux pas.
>>>>
>>>> I suspect that given the number of avid cyclists on this list
>>>> that
>>>> someone will be immediately able to say "actually that's wrong"
>>>> or
>>>> "actually, that's correct because..."
>>>>
>>>> Best Regards,
>>>>
>>>> Andy
>>>>
>>>>
>>>>
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>>>
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