[Talk-GB] National Cycle Network discrepancies between Sustrans and OSM data

Mon Feb 27 16:31:10 UTC 2023

I will try and encourage Sustrans to setup some method of accepting 
error reports for their maps (and to actually action the reports). My 
understanding is that the network is "owned" by a series of Network 
Managers (who each have an area of a few counties) and these Network 
Managers are the only ones who can authorise changes to the official 
Sustrans map. I've been frustrated (as have others) by the lack of 
response to reports of what seem to be obvious errors in the Sustrans 
mapping but I'll keep on at Sustrans.

Eventually I'd hope that the Sustrans and OSM maps become much closer 
and that the Sustrans mapping can be taken as "the truth" but, at the 
moment, the quality of the Sustrans mapping includes too many errors for 
this to be possible.

In your specific example, I'd bet that Sustrans have just been very slow 
in adding the new NCN422 to their maps and this is a good example of 
where I hope they're able to use my comparison work to improve things.

Ian

On 25/02/2023 21:29, Jon Pennycook wrote:
> Hello Ian.
>
> "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"
> NCN422 is signposted and appears on the local council maps.  It was 
> supposed to run from Newbury to Windsor (or maybe Legoland) along the 
> A4 and A329 and then along an unknown route to Windsor, but Windsor & 
> Maidenhead Council (who cover Ascot as well as Windsor) pulled out of 
> the scheme - I think this may have been because of problems with the 
> royal lands (something about cycling infrastructure next to a busy 
> road causing damage to the environment).
> https://www.reading.gov.uk/vehicles-roads-and-transport/transport-schemes-and-projects/ncn-cycle-route-422/
> https://www.reading.gov.uk/vehicles-roads-and-transport/cycling/
> https://www.wokingham.gov.uk/EasysiteWeb/getresource.axd?AssetID=373358&type=full&servicetype=Attachment 
> <https://www.wokingham.gov.uk/EasysiteWeb/getresource.axd?AssetID=373358&type=full&servicetype=Attachment>
> https://www.wokingham.gov.uk/roadworks-and-outdoor-maintenance/major-new-roads/a329-cycleway/
> https://democracy.slough.gov.uk/mgConvert2PDF.aspx?ID=73452
>
> Of course, it's possible that after being allocated a route number, 
> maybe Sustrans rejected the actual infrastructure as being 
> substandard, but I've never heard of them doing such a thing.  
> However, in that case, I wouldn't have expected the councils to spend 
> money on attaching NCN422 to their signs.
> Some of the discrepancies near me are due to new housing developments 
> - developers seem able to close or divertparts of the National Cycle 
> Network without anyone noticing, and some others are due to 
> improvements (like safe crossings of dual carriageways).
>
> Jon
>
> ------------------------------------------------------------------------
> *From:* Ian Dent <ian at dent.org.uk>
> *Sent:* 25 February 2023 20:45
> *To:* talk-gb at openstreetmap.org <talk-gb at openstreetmap.org>
> *Subject:* [Talk-GB] National Cycle Network discrepancies between 
> Sustrans and OSM data
>
> 	
> You don't often get email from ian at dent.org.uk. Learn why this is 
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> 	
>
> 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.
>
> I’ve found that the NCN plotted on OpenStreetMap differs in a number 
> of places from that in the Sustrans mapping.
>
> I’ve created a coarse visualisation of the differences – see 
> https://dent.org.uk/sustrans/sustrans-ncn-inconsistences/ 
> <https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdent.org.uk%2Fsustrans%2Fsustrans-ncn-inconsistences%2F&data=05%7C01%7Cjon.pennycook1%40physics.org%7C1f740373fd8c4064bf2508db1771d2cd%7C8b8986af18bb4882a149fa5a3dd1f995%7C0%7C0%7C638129549855692997%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=WgJi4vDdJy0k7uLLvEDeZUY%2B01aPrQn8DjXDXAnNeN0%3D&reserved=0> 
> - 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.
>
> 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.
>
> 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.
>
> 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.
>
> 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.
>
> Discrepancies are for various reasons including:
>
>  *
>
>     mismatches on how the route is mapped (the map shows differences
>     of 10 metres or more).
>
>  *
>
>     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
>
>  *
>
>     New Sustrans routes that haven’t yet reached OSM – e.g. NCN 28
>     east of Plymouth
>
>  *
>
>     Routes that Sustrans classes as “links” but OSM has as NCN – e.g.
>     NCN 28 near Dartmouth. I think these are generally Sustrans errors.
>
>  *
>
>     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
>
>  *
>
>     Some ferries are included as routes in OSM – e.g. NCN 2 near Plymouth
>
> Sustrans data for the NCN can be found at 
> https://data-sustrans-uk.opendata.arcgis.com/ 
> <https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdata-sustrans-uk.opendata.arcgis.com%2F&data=05%7C01%7Cjon.pennycook1%40physics.org%7C1f740373fd8c4064bf2508db1771d2cd%7C8b8986af18bb4882a149fa5a3dd1f995%7C0%7C0%7C638129549855692997%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=atb6f2ioaAi1tsP%2FJsmme7FwLlte6cm8DDM%2B8dMwarI%3D&reserved=0> 
> (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.
>
> 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).
>
> Thanks to those who’ve already discussed this with me – particularly 
> the recent East Midlands OSM meeting.
>
> Ian
>
>
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