[Talk-GB] Footpaths - search for the missing ones

Rob Nickerson rob.j.nickerson at gmail.com
Sat May 12 22:49:19 UTC 2018


Hi Jerry, Nick, Richard,

Footpaths was what got me in to OSM so I'm so pleased to see all this :-)
You've got me excited about getting back out there over the summer and
picking up as many new paths as possible.

@Jerry: Your comment about the GB1900 caught me off guard at first. You
seem to be saying that even with filtering there are still too many results
from GB1900 to investigate. Caught off guard because isn't this OSM's
strength - the ability to go out and crowd source all this? Re-reading your
post, I see that what you are saying is that OSM has a lot of missing paths
but the rowmaps data is just a good as a starting point for finding these.
The GB1900 data might them be used to find stuff missing from the local
authorities dataset. Is that right or am I still not understanding?

I think we can do a project here. As you know, I'm not so good on the
technical side, but am more than willing to throw my support behind any
project where I can (e.g. engaging with NLS, comms, promotion, seeking new
members to join the hunt and therefore join OSM). It sounds like this is
what the 3 of you are looking at this already :-). Give me a shout if you
need anything.

>Is there permission to use OOC tiles

>The NLS 6 inch maps are needed for good comparison, although I suspect
many paths will be on 1:25k

I'm not sure about the OOC tiles; I think Andy Robinson (blackadder) was
involved with the scanning, but ultimatley these are hosted on OSM servers
so you need to check with them.

We do have a great relationship with the NLS though. Although they have put
some of their maps behind a subscription API, they are big supporters of
the OSM (and OHM) projects. The publish 6 inch and 25 inch [1] for all of
Great Britain now. I am more than willing to speak with NLS to see if we
can formalise this as part of a footpath project. There's no harm in
asking! Just let me know.

P.S. Sorry if this feels like me being slow / repeating the obviously - am
feeling under the weather at the moment

[1] https://maps.nls.uk/openlayers/?m=1&id=176

*Rob*


On Fri, 11 May 2018 at 16:40, SK53 <sk53.osm at gmail.com> wrote:

> Quick impressions:
>
>    - There's a fair amount of noise in text, but most are "F.P."
>    - Lat/lon could be reduced from 15 decimal places, would make file
>    size far smaller. OSM use 7, but I suspect 5 (~ 1 m accuracy) would be fine.
>    - Filtering by a buffer round OSM roads does not reduce count enough
>    to be useful. 21k points in East Mids goes to 14k with 20 m buffer, 10 with
>    50 m buffer.
>    - Instead created 1000 m buffer around points and looked for distance
>    from OSM highways in that buffer. This allows to focus on points which are
>    distant from existing highways.
>    - In the main dots which are a long way from highways are clustered in
>    areas we already know lack footpaths. Map shows points over 400 m from an
>    OSM highway, underlain by a heatmap of total length of missing prows. It is
>    apparent that these are coincident (W of Derby, around Buxton, SE
>    Derbyshire, Trent Valley in N Notts, much of Lincolnshire). Other areas may
>    be simply a result of rather different comparison periods for the data
>    (distance from road is 3 years old OSM data).
>    https://www.dropbox.com/s/nz0893l9io61vtk/gb1900_fps1.jpg?dl=0
>    - Paths which were formerly isolated may now be close to new roads and
>    therefore get discarded with use of buffers or short distances.
>    - Not clear that searching in urban areas is worthwhile. Using
>    something like the OS Urban Area shape files may reduce volume.
>    - Even with these filters the total points more than 500 m from a
>    (2015) OSM road is nearly a 1000 for the East Midlands
>    - The NLS 6 inch maps are needed for good comparison, although I
>    suspect many paths will be on 1:25k
>    - There are interesting paths which seem to have disappeared entirely
>    from the PRoW network, but noting them does require local knowledge rather
>    than a bulk comparison. Here are a couple I noted, which also appear on
>    1:25k and therefore look like prima facie cases for lost paths:
>    - https://openstreetmap.lu/os-ooc-nls.html#16/52.9181/-1.2688/nlsos1
>       path N-S from New Farm
>       - https://openstreetmap.lu/os-ooc-nls.html#16/52.9503/-1.2603/nlsos1
>       path from Noggins Nook to Swanacar Farm
>
> So broadly in conclusion: it doesn't seem to give more than comparison
> against rowmaps for identifying missing paths for OSM, but it does have
> potential for finding lost paths. For the latter case rather more
> annotation of information would be needed.
>
>
> Jerry
>
> On 10 May 2018 at 22:50, Rob Nickerson <rob.j.nickerson at gmail.com> wrote:
>
>> Many thanks. Now shared with Richard, Nick and Jerry. Wont share publicly
>> yet as I wouldn't want to disrupt the project comms plan.
>>
>> @Dave: Oh yes this is definitely not for OSM import. It's node data for
>> linear features for a start!! No, instead this can be used to identify
>> possible missing paths which should then be investigated using ground
>> survey, aerial imagery and GPS (or Strava) data. See it as a helping hand
>> to direct you where to look.
>>
>> Best,
>> Rob
>>
>>
>>
>>
>>
>> On Thu, 10 May 2018, 13:54 SK53, <sk53.osm at gmail.com> wrote:
>>
>>> Quick correction, as I uploaded heat map to wrong Flickr account. This
>>> is the proper link: https://flic.kr/p/JSXgyh.
>>>
>>> J
>>>
>>
>> On 10 May 2018 1:54 p.m., "SK53" <sk53.osm at gmail.com> wrote:
>>
>> Quick correction, as I uploaded heat map to wrong Flickr account. This is
>> the proper link: https://flic.kr/p/JSXgyh.
>>
>> J
>>
>> On 10 May 2018 at 13:07, SK53 <sk53.osm at gmail.com> wrote:
>>
>>> I just checked on the Vision of Britain site: the core data is currently
>>> released under CC-BY-NC. I presume OSM-UK have a waiver from these terms.
>>>
>>> Undoubtedly there will be rights of way which have effectively fallen in
>>> to abeyance. I noted one the other day which was on NPE maps, but no longer
>>> visible on the ground nor on modern OS maps, nor in the data available from
>>> rowmaps. Broadly speaking such paths fall outside the ambit of OSM, but
>>> finding such things is very valuable.
>>>
>>> Note that we have other sources as well. As a quick experiment I spent
>>> 15 minutes quickly tracing paths marked on NPE maps for SE Notts and
>>> managed just over 200 using JOSM. This is of course what I should have done
>>> many years ago rather than adding them to OSM (hindsight is a wonderful
>>> thing). The geometry wont be very good, but can be refined using the 1:25
>>> OOC maps. Such data can be more useful than the raw names from GB1900, but
>>> could be used in conjunction. Furthermore with suitable tagging this can be
>>> added to OHM (I would suggest start_date=1900-01-01 with
>>> end_date=1950-12-31 unless one knows path is still in use) which makes it a
>>> tad easier for sharing (although OHM overpass instance is not working atm).
>>>
>>> A couple of other things to note regarding the GB1900 data:
>>>
>>>
>>>    - Many current footpaths will be marked as Bridle Roads (B.R.). It
>>>    would be useful to add these names to the available data.
>>>    - footpaths and bridle roads often fall well short of their current
>>>    entry points because the current right of way will have followed farm
>>>    tracks and service roads, which in many cases have disappeared.
>>>
>>> Returning to use of rowmaps I have a recent geojson file of missing
>>> paths in the North Midlands (Staffs, Derbys, Notts, Leics & Rutland) up on
>>> github: https://github.com/SK53/osm-prow-stats. I intend to add other
>>> areas as time permits. Unfortunately I've never got my comparison process
>>> to work on PostGIS so I still use QGIS which is a little unwieldy for
>>> automation. I process rowmaps data into a fairly standard form in PostGIS
>>> before making the comparisons. This <https://flic.kr/p/25DgebX>is a
>>> heat map of missing footpaths in the East Midlands area as of Autumn 2017,
>>> I compare length of missing paths with total length in a tetrad (2km grid
>>> square). It readily shows hotspots of missing paths. This was done to
>>> identify suitable places for our 2018 New Year footpath mapping. The
>>> National Forest area in SE Derbyshire still has a lot of outstanding
>>> mapping to do: it's not too bad as walking country either.
>>>
>>> Jerry
>>>
>>>
>>>
>>>
>>> On 10 May 2018 at 11:34, Nick Whitelegg <nick.whitelegg at solent.ac.uk>
>>> wrote:
>>>
>>>>
>>>> I might be potentially interested in developing something with this
>>>> data, partly because I already run a site (freemap) which shows OSM maps
>>>> for walkers and stores them in a PostGIS database - so it should be an easy
>>>> process to filter out the data to find those points which are not close to
>>>> an OSM highway. It would also be easy for me to adapt my existing code to
>>>> visualise these "FP" points. Presumably they are just points with no
>>>> indication of direction of the path? An "FP" label presumably has
>>>> orientation so something could possibly be deduced about its course at that
>>>> point if orientation was available too.
>>>>
>>>>
>>>> I also already visualise the data so visualising the missing ROWs would
>>>> be easily done too.
>>>>
>>>>
>>>> It would be nice to develop features to find nearby locations where
>>>> there are lots of these missing paths, e.g. if I am in Southampton, find
>>>> the nearest village with 10, 20 (or whatever) missing paths within a 5-mile
>>>> radius.
>>>>
>>>>
>>>> Would be nice to have an app too so you can find these footpaths while
>>>> you're actually out.
>>>>
>>>>
>>>>
>>>> So potentially interested in this, yes. I don't want to commit 100% but
>>>> would be nice to have the data.
>>>>
>>>>
>>>> Nick
>>>>
>>>>
>>>>
>>>> ------------------------------
>>>> *From:* Richard Fairhurst <richard at systemed.net>
>>>> *Sent:* 10 May 2018 09:07:49
>>>> *To:* talk-gb at openstreetmap.org
>>>> *Subject:* Re: [Talk-GB] Footpaths - search for the missing ones
>>>>
>>>> Rob Nickerson wrote:
>>>> > Basically we have point data of historic footpaths (some 300k points)
>>>> and
>>>> > I think it would be amazing to compare this to OSM to see if we can
>>>> find
>>>> > more footpaths to map.
>>>>
>>>> Very cool. Could you post the data somewhere?
>>>>
>>>> Richard
>>>>
>>>>
>>>>
>>>> --
>>>> Sent from: http://gis.19327.n8.nabble.com/Great-Britain-f5372682.html
>>>>
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>>>
>>
>>
>
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