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

Fri Jan 14 18:51:25 UTC 2022

Thanks everyone - https://www.openstreetmap.org/relation/21895 looks a 
lot more sensible now.

Best Regards,

Andy

On 14/01/2022 18:15, Dave F via Talk-GB wrote:
> 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
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Talk-GB mailing list
>>>>> Talk-GB at openstreetmap.org
>>>>> https://lists.openstreetmap.org/listinfo/talk-gb
>>>>
>>>>
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