Re: Finding Unmapped public rights of way

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Re: Finding Unmapped public rights of way

Dudley Ibbett
Hi

I'm trying to make use of the row files on rowmaps for derbyshire and staffordshire and and merging these with and osm map file to then produce maps that can highlight which paths are and aren't mapped.  I can put the derbyshire file into JOSM and download parts of the area and merge them to create an osm file that I can then save locally and import into Maperative.  A modified rules file allows me to produce the prow footpath ways and the osm footpath ways as different coloured dotted lines so I can see which are/aren't mapped.  Unfortunately JOSM doesn't seem to be able to cope with merging large files.  I maybe asking to much of it as the files are quite big.  What I would like is to be able to get a merged file of the derbyshire, saffordshire row files and the equivalent osm map file on a regular basis (highlighting the rows that aren't mapped) so I can slowly pick away at the remaining footpaths the need mapping in this area.  Does anyone know of a simple way to do this?

Many Thanks

Dudley

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Re: Finding Unmapped public rights of way

Steven Horner
Hello,

If you are just wanting to visualy inspect them, could you do it in TileMill. I produced a map of a large part of County Durham that showed both OSM footpaths and PRoW differently coloured. It produced a MBtiles file which I then converted to Z,X,Y PNG tiles I then added that as a source into a local OpenLayers site which allowed me to view it from any browser. You could convert it to another map format with Mobile Atlas Creator and view the map that way. You could even use the produced map as a background in JOSM if you then want to trace the paths?

You could also do it in QGIS and could probably get it to highlight only the paths that are missing.

Not sure if either of those is exactly what you are after.

Steven

On 27 Jul 2013 13:12, "Dudley Ibbett" <[hidden email]> wrote:
Hi

I'm trying to make use of the row files on rowmaps for derbyshire and staffordshire and and merging these with and osm map file to then produce maps that can highlight which paths are and aren't mapped.  I can put the derbyshire file into JOSM and download parts of the area and merge them to create an osm file that I can then save locally and import into Maperative.  A modified rules file allows me to produce the prow footpath ways and the osm footpath ways as different coloured dotted lines so I can see which are/aren't mapped.  Unfortunately JOSM doesn't seem to be able to cope with merging large files.  I maybe asking to much of it as the files are quite big.  What I would like is to be able to get a merged file of the derbyshire, saffordshire row files and the equivalent osm map file on a regular basis (highlighting the rows that aren't mapped) so I can slowly pick away at the remaining footpaths the need mapping in this area.  Does anyone know of a simple way to do this?

Many Thanks

Dudley

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Re: Finding Unmapped public rights of way

Craig Wallace
In reply to this post by Dudley Ibbett
On 2013-07-27 13:11, Dudley Ibbett wrote:

> Hi
>
> I'm trying to make use of the row files on rowmaps for derbyshire and
> staffordshire and and merging these with and osm map file to then
> produce maps that can highlight which paths are and aren't mapped.  I
> can put the derbyshire file into JOSM and download parts of the area and
> merge them to create an osm file that I can then save locally and import
> into Maperative.  A modified rules file allows me to produce the prow
> footpath ways and the osm footpath ways as different coloured dotted
> lines so I can see which are/aren't mapped.  Unfortunately JOSM doesn't
> seem to be able to cope with merging large files.  I maybe asking to
> much of it as the files are quite big.  What I would like is to be able
> to get a merged file of the derbyshire, saffordshire row files and the
> equivalent osm map file on a regular basis (highlighting the rows that
> aren't mapped) so I can slowly pick away at the remaining footpaths the
> need mapping in this area.  Does anyone know of a simple way to do this?

Depends on how big the files are, and how much memory you have on your
computer. You can assign more memory to JOSM, which might help. eg run
it with a command like this:
java -Xmx1500M -jar josm-tested.jar
That would allow it 1500MB.


Or for merging large files, you could use Osmosis.
http://wiki.openstreetmap.org/wiki/Osmosis
ie use a command like this:
osmosis --rx file2.osm --rx file1.osm --m --wx merged.osm

Craig

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Re: Finding Unmapped public rights of way

Steven Horner
I did a little bit of work early this morning on this for County Durham but its very rough and nowhere near 100% accurate but gives a good idea of the status of PRoW mapped in the area.

If you have a look at the 2 images linked below they show PRoW in County Durham, one with background mapping, the other without. Green are PRoW mapped in OSM, Red are PRoW not mapped in OSM.


This is very far from 100% accurate, but from visual inspection was quite close.

I created this in QGIS comparing the OSM data to the PRoW released from Durham County Council, I created a special query using intersects. This is why it's not perfectly accurate because if an OSM mapped math intersected with the PRoW data it would show up green, even though it may not be that actual PRoW. A lot more work could be done to make this more accurate but this was done in about 90 minutes this morning and most of that time was spent converting OSM files and filtering out data I did not need.

I intend to write up what I did to create this, rough notes already done and this may help others and hopefully someone can think of a much better way. I am a beginner at most of this.


On Sun, Jul 28, 2013 at 2:05 AM, Craig Wallace <[hidden email]> wrote:
On 2013-07-27 13:11, Dudley Ibbett wrote:
Hi

I'm trying to make use of the row files on rowmaps for derbyshire and
staffordshire and and merging these with and osm map file to then
produce maps that can highlight which paths are and aren't mapped.  I
can put the derbyshire file into JOSM and download parts of the area and
merge them to create an osm file that I can then save locally and import
into Maperative.  A modified rules file allows me to produce the prow
footpath ways and the osm footpath ways as different coloured dotted
lines so I can see which are/aren't mapped.  Unfortunately JOSM doesn't
seem to be able to cope with merging large files.  I maybe asking to
much of it as the files are quite big.  What I would like is to be able
to get a merged file of the derbyshire, saffordshire row files and the
equivalent osm map file on a regular basis (highlighting the rows that
aren't mapped) so I can slowly pick away at the remaining footpaths the
need mapping in this area.  Does anyone know of a simple way to do this?

Depends on how big the files are, and how much memory you have on your computer. You can assign more memory to JOSM, which might help. eg run it with a command like this:
java -Xmx1500M -jar josm-tested.jar
That would allow it 1500MB.


Or for merging large files, you could use Osmosis. http://wiki.openstreetmap.org/wiki/Osmosis
ie use a command like this:
osmosis --rx file2.osm --rx file1.osm --m --wx merged.osm

Craig


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 0191 645 2265 

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Re: Finding Unmapped public rights of way

Rob Nickerson
In reply to this post by Dudley Ibbett
>I created this in QGIS comparing the OSM data to the PRoW released from
>Durham County Council, I created a special query using intersects. This is
>why it's not perfectly accurate because if an OSM mapped math intersected
>with the PRoW data it would show up green, even though it may not be that
>actual PRoW. A lot more work could be done to make this more accurate ..

>I intend to write up what I did to create this, rough notes already done
>and this may help others and hopefully someone can think of a much better
>way. I am a beginner at most of this.

Thanks,

Appreciate anything you can write up to help others. I will correct you: "I *WAS* a beginner at most of this". :-)

In regards to the Intersect issue, I had intended to look at this sort of thing in QGIS myself, but I have been way too busy with SOTM. As I'm not a GIS professional either I would struggle to work out how to do a comparison between OSM and the LA data, but you could try looking at these ideas [1] or send an email to QGIS's mailing list [2].

Rob

[1] http://lists.openstreetmap.org/pipermail/dev/2013-January/026408.html
[2] http://www.qgis.org/community/mailing-lists.html

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Re: Finding Unmapped public rights of way

Phil Endecott
In reply to this post by Dudley Ibbett
Dudley Ibbett wrote:
> I'm trying to make use of the row files on rowmaps for derbyshire and
> staffordshire and and merging these with and osm map file to then produce
> maps that can highlight which paths are and aren't mapped.

Thanks for doing this.

One suggestion - it would be great if the disgnation=public_footpath/bridleway
tags on existing paths could be tidied up at the same time.  Last time
I looked,
too few had these tags to be able to use them exclusively to identify footpaths,
and the other tag combinations tend to have many false positives.


Regards,  Phil.





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Re: Finding Unmapped public rights of way

sk53.osm
Hmm, I have sitting on my desktop a whole load of QGIS analyses of OSM designation=* against the DCC rowmap TAB file, but as I'm on my way to SotM Baltics wont write this up until I get back.

I haven't looked in detail, but basic use of buffers seems to grab most matching footpaths (buffer OSM data, and then use the buffered data to clip the DCC PRoW data). Obviously crossing paths are also captured, but it should be relatively easy to find only those footpaths where more than n% of the route is within the buffered OSM path.

So far I've used buffers of 10, 50 and 100m against the OSM data.

I havent loaded the TAB file into PostGIS as there was some kind of geometry problem.

Jerry



On Sun, Jul 28, 2013 at 3:33 PM, Phil Endecott <[hidden email]> wrote:
Dudley Ibbett wrote:
I'm trying to make use of the row files on rowmaps for derbyshire and staffordshire and and merging these with and osm map file to then produce maps that can highlight which paths are and aren't mapped.

Thanks for doing this.

One suggestion - it would be great if the disgnation=public_footpath/bridleway
tags on existing paths could be tidied up at the same time.  Last time I looked,
too few had these tags to be able to use them exclusively to identify footpaths,
and the other tag combinations tend to have many false positives.


Regards,  Phil.






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Re: Finding Unmapped public rights of way

Dudley Ibbett
I have tried increasing the memory allocated to JOSM but it is still a very slow process.  The most convenient way for me would be to download the Geofrabik file for derbyshire when I need and update but it looks like a merge with the derbyshire prow will take an hour or more at the current rate of progress.

Osmosis is unfortunately producing an error.  SEVERE: Thread for task 1-rx failed org.openstreetmap.osmosis.core.OsmosisRuntimeException: Node -272236 does not ha
ve a version attribute as OSM 0.6 are required to have.  Is this a 0.5 file?

So it seems the file format may not be right.

I'm afraid the other types of analysis are a bit beyond me but it would be a useful tool to have is someone can highlight prows not mapped.  To be useful it would need frequent updates and enable walks to be planned to cover the ground.  I guess having some stats would be nice to monitor progress.

I do put in the designation on paths etc. when I find they are missing. 

At the moment I only put in new footpaths if I have walked them.  I assume this is what others have done before in my part of the world and it would seem the right approach at the moment and possibly a selling point for OSM maps in the future.   It seems a good approach given there is already reasonable coverage but it may not be so applicable where there isn't.  Something for debate perhaps.

Many thanks for the responses.

Regards

Dudley






Date: Sun, 28 Jul 2013 17:33:21 +0100
From: [hidden email]
To: [hidden email]
CC: [hidden email]
Subject: Re: [Talk-GB] Finding Unmapped public rights of way

Hmm, I have sitting on my desktop a whole load of QGIS analyses of OSM designation=* against the DCC rowmap TAB file, but as I'm on my way to SotM Baltics wont write this up until I get back.

I haven't looked in detail, but basic use of buffers seems to grab most matching footpaths (buffer OSM data, and then use the buffered data to clip the DCC PRoW data). Obviously crossing paths are also captured, but it should be relatively easy to find only those footpaths where more than n% of the route is within the buffered OSM path.

So far I've used buffers of 10, 50 and 100m against the OSM data.

I havent loaded the TAB file into PostGIS as there was some kind of geometry problem.

Jerry



On Sun, Jul 28, 2013 at 3:33 PM, Phil Endecott <[hidden email]> wrote:
Dudley Ibbett wrote:
I'm trying to make use of the row files on rowmaps for derbyshire and staffordshire and and merging these with and osm map file to then produce maps that can highlight which paths are and aren't mapped.

Thanks for doing this.

One suggestion - it would be great if the disgnation=public_footpath/bridleway
tags on existing paths could be tidied up at the same time.  Last time I looked,
too few had these tags to be able to use them exclusively to identify footpaths,
and the other tag combinations tend to have many false positives.


Regards,  Phil.






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Re: Finding Unmapped public rights of way

sk53.osm
In reply to this post by sk53.osm
Overview of missing Derbyshire footpaths: http://www.flickr.com/photos/sk53_osm/9390856924/

Jerry


On Sun, Jul 28, 2013 at 5:33 PM, sk53.osm <[hidden email]> wrote:
Hmm, I have sitting on my desktop a whole load of QGIS analyses of OSM designation=* against the DCC rowmap TAB file, but as I'm on my way to SotM Baltics wont write this up until I get back.

I haven't looked in detail, but basic use of buffers seems to grab most matching footpaths (buffer OSM data, and then use the buffered data to clip the DCC PRoW data). Obviously crossing paths are also captured, but it should be relatively easy to find only those footpaths where more than n% of the route is within the buffered OSM path.

So far I've used buffers of 10, 50 and 100m against the OSM data.

I havent loaded the TAB file into PostGIS as there was some kind of geometry problem.

Jerry



On Sun, Jul 28, 2013 at 3:33 PM, Phil Endecott <[hidden email]> wrote:
Dudley Ibbett wrote:
I'm trying to make use of the row files on rowmaps for derbyshire and staffordshire and and merging these with and osm map file to then produce maps that can highlight which paths are and aren't mapped.

Thanks for doing this.

One suggestion - it would be great if the disgnation=public_footpath/bridleway
tags on existing paths could be tidied up at the same time.  Last time I looked,
too few had these tags to be able to use them exclusively to identify footpaths,
and the other tag combinations tend to have many false positives.


Regards,  Phil.






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Re: Finding Unmapped public rights of way

Phil Endecott
sk53.osm wrote:
> Overview of missing Derbyshire footpaths:
> http://www.flickr.com/photos/sk53_osm/9390856924/

Interesting.

I think you're comparing the prow map with OSM paths tagged
designation=public_footpath/bridleway.  You would see a lot more
green if you compared with all OSM paths (& tracks).  It would
be great to see a breakdown of X% mapped with designation
tag, Y% mapped without that tag, and Z% not mapped at all.

Personally, I'd support some sort of semi-automatic addition of
designation= tags to paths that have e.g. highway=footway and
that are near-coincident with things in the prow map.  Do you
have the technology to do that?


Regards,  Phil.





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Re: Finding Unmapped public rights of way

Robert Whittaker (OSM lists)
In reply to this post by Dudley Ibbett
On 27 July 2013 13:11, Dudley Ibbett <[hidden email]> wrote:
> I'm trying to make use of the row files on rowmaps for derbyshire and
> staffordshire and and merging these with and osm map file to then produce
> maps that can highlight which paths are and aren't mapped.  I can put the
> derbyshire file into JOSM and download parts of the area and merge them to
> create an osm file that I can then save locally and import into Maperative.

I assume that these digitised PRoW Maps from local councils are
released under the OS OpenData License. That being the case, please
note that Ordnance Survey have recently stated that their "OS OpenData
licence is not forward compatible with the ODC-By and ODbL" [1]. Hence
these datasets cannot currently be used as direct sources for
contributing to OSM.

Of course this doesn't prevent individuals generating data comparisons
and then using them to focus mapping efforts that make use of other
sources. And hopefully OS will be persuaded to amend their license, so
we can start making full use of these PRoW GIS datasets.

Robert.

[1] http://robert.mathmos.net/osm/os-open-data.html

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Re: Finding Unmapped public rights of way

Steven Horner

Personally I just produced the Durham map to show how much work is still to be done.

Then use this as a basis to go out and survey.

A lot of the PRoW are incorrect anyway when actually on the ground. Even when they have been amended officially, either the council doesn't update their data or ordnance survey have not used the data sent.

This is one of the biggest advantages to OSM, it is updated. If the OSM and walking community could come together to fill in the missing data. For instance I know the Ramblers in Durham walked every path in the county a couple of years ago. I wonder if they have the GPX tracks, I will make enquiries.

On 29 Jul 2013 12:53, "Robert Whittaker (OSM lists)" <[hidden email]> wrote:
On 27 July 2013 13:11, Dudley Ibbett <[hidden email]> wrote:
> I'm trying to make use of the row files on rowmaps for derbyshire and
> staffordshire and and merging these with and osm map file to then produce
> maps that can highlight which paths are and aren't mapped.  I can put the
> derbyshire file into JOSM and download parts of the area and merge them to
> create an osm file that I can then save locally and import into Maperative.

I assume that these digitised PRoW Maps from local councils are
released under the OS OpenData License. That being the case, please
note that Ordnance Survey have recently stated that their "OS OpenData
licence is not forward compatible with the ODC-By and ODbL" [1]. Hence
these datasets cannot currently be used as direct sources for
contributing to OSM.

Of course this doesn't prevent individuals generating data comparisons
and then using them to focus mapping efforts that make use of other
sources. And hopefully OS will be persuaded to amend their license, so
we can start making full use of these PRoW GIS datasets.

Robert.

[1] http://robert.mathmos.net/osm/os-open-data.html

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Re: Finding Unmapped public rights of way

sk53.osm
In reply to this post by Phil Endecott

That's exactly what I am doing. I've described the method so others are welcome to apply it.

The problem of comparing PRoW against the path network is more complex: many rights of way will run along service roads (farm driveways) or tracks. In places with many paths, the buffer approach may result in erroneous matches and is probably useless in urban settings.

Personally, I think its better to use this type of information as the basis for survey. Missing designation information likewise: I was surprised to find I could not recall the status of paths in the Long Eaten area which I use from time to time.

Jerry

On Jul 29, 2013 12:20 PM, "Phil Endecott" <[hidden email]> wrote:
sk53.osm wrote:
Overview of missing Derbyshire footpaths:
http://www.flickr.com/photos/sk53_osm/9390856924/

Interesting.

I think you're comparing the prow map with OSM paths tagged
designation=public_footpath/bridleway.  You would see a lot more
green if you compared with all OSM paths (& tracks).  It would
be great to see a breakdown of X% mapped with designation
tag, Y% mapped without that tag, and Z% not mapped at all.

Personally, I'd support some sort of semi-automatic addition of
designation= tags to paths that have e.g. highway=footway and
that are near-coincident with things in the prow map.  Do you
have the technology to do that?


Regards,  Phil.





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Re: Finding Unmapped public rights of way

Phil Endecott
In reply to this post by Robert Whittaker (OSM lists)
Robert Whittaker wrote:
> I assume that these digitised PRoW Maps from local councils are
> released under the OS OpenData License. That being the case, please
> note that Ordnance Survey have recently stated that their "OS OpenData
> licence is not forward compatible with the ODC-By and ODbL" [1]. Hence
> these datasets cannot currently be used as direct sources for
> contributing to OSM.

I absolutely agree that the paths from these maps cannot be imported
into OSM with the current licensing.  This is clear.

However, it would be great if we could use them just to add the
"designation=public_footpath" tags to paths that have already been
surveyed.

Do people think it would be acceptable to, for example, view a paper
definitive map at the local council office, and then update the
designation tags manually?

If that's allowed, surely it is possible to construct an argument that
an automated equivalent process using the digital versions of the maps
is allowed.

Is it possible to claim that while the geometry of the path is derived
from the OS, the fact of it being a public footpath is something added
by the local authority; if OSM substitutes its own path geometry, the
OS intellectual property is removed.  Ideally, the local authority
would then disclaim any rights (or adopt the plain OGL) over the remaining
data: after all, they are only using the OS licence because of the OS-
derived elements.

Hmmm, that's not too convincing.  Maybe someone else can come up with
a better argument.



Cheers,  Phil.





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Re: Finding Unmapped public rights of way

David Groom
----- Original Message -----
From: "Phil Endecott" <[hidden email]>
To: <[hidden email]>
Sent: Wednesday, July 31, 2013 1:50 PM
Subject: Re: [Talk-GB] Finding Unmapped public rights of way


> Robert Whittaker wrote:
>> I assume that these digitised PRoW Maps from local councils are
>> released under the OS OpenData License. That being the case, please
>> note that Ordnance Survey have recently stated that their "OS OpenData
>> licence is not forward compatible with the ODC-By and ODbL" [1]. Hence
>> these datasets cannot currently be used as direct sources for
>> contributing to OSM.
>
> I absolutely agree that the paths from these maps cannot be imported
> into OSM with the current licensing.  This is clear.
>
> However, it would be great if we could use them just to add the
> "designation=public_footpath" tags to paths that have already been
> surveyed.
>
> Do people think it would be acceptable to, for example, view a paper
> definitive map at the local council office, and then update the
> designation tags manually?

Probably not. If its a paper map then its still likely to have copyright on
it.

A far better approach (which some contributors are following[1]) would be to
ask to see the definitive statement (not the definitive map) and then ask
the local authority to release the definitive statement under the unmodifed
OGL.  As far as I am aware the OS are still of the opinion that they have no
IP in the Definitive satement [2].

David

[1] http://wiki.openstreetmap.org/wiki/UK_local_councils#List_of_UK_Councils
[2] http://blog.ordnancesurvey.co.uk/2010/04/os-opendata-goes-live/  Post
from "Paul" on 23 June 2010 @ 10:48am

>
> If that's allowed, surely it is possible to construct an argument that
> an automated equivalent process using the digital versions of the maps
> is allowed.
>
> Is it possible to claim that while the geometry of the path is derived
> from the OS, the fact of it being a public footpath is something added
> by the local authority; if OSM substitutes its own path geometry, the
> OS intellectual property is removed.  Ideally, the local authority
> would then disclaim any rights (or adopt the plain OGL) over the remaining
> data: after all, they are only using the OS licence because of the OS-
> derived elements.
>
> Hmmm, that's not too convincing.  Maybe someone else can come up with
> a better argument.
>
>
>
> Cheers,  Phil.



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Re: Finding Unmapped public rights of way

Robert Whittaker (OSM lists)
On 31 July 2013 17:36, David Groom <[hidden email]> wrote:
> A far better approach (which some contributors are following[1]) would be to
> ask to see the definitive statement (not the definitive map) and then ask
> the local authority to release the definitive statement under the unmodified
> OGL.

That's what I've been doing. To help with matching up the paths in OSM
with those in the Definitive Statements, I've been adding prow_ref=*
tags to the ways, and then ticking them off on a list I've made. The
prow_ref values I've entered have been of the form "<Parish>
[FP|BR|RB|BY] <num>" (e.g. "Bredon FP 2") unless there is an
alternative format that is consistently used by the Council.

I've found the usefulness of the Definitive Statements is quite
variable. Modern descriptions are generally very good, with lots of
detail and grid references included. Older ones might contain very
little useful detail, and often reference historic names for places /
roads that are no longer in use. In working out where paths are, I've
found it very helpful to consult the Out-of-Copyright OS maps (eg via
the background layers in Potlatch). These don't specifically mark
PRoWs, but they do include a lot of historic paths and tracks -- many
of which are now PRoW -- and various old place and road names.

To help with mapping PRoW, I've collected together a few resources
that others might be interested in at
http://robert.mathmos.net/osm/prow/ -- including some advice for
requesting Definitive Statements from Councils, various visualisation
tools, and copies of the Definitive Statements I've managed to get
hold of.

Robert.

> [1] http://wiki.openstreetmap.org/wiki/UK_local_councils#List_of_UK_Councils

--
Robert Whittaker

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