[Talk-GB] Definitive Ways - tagging? (was Re: Talk-GB Digest, Vol 44, Issue 19)

[Mike Harris]

Ian

I am on board with the concept and the need to sort out our tagging.

However, your category (1) - the OS version - has nothing official about 
it. The OS themselves include a disclaimer on all of their maps so far 
as the line of rights of way are concerned. The ONLY official line is 
the one shown on the (original) definitive map as modified from time to 
time by the Highway Authority (or as described in the Definitive 
Statement which takes precedence where this differs from the Definitive 
Map). Anything else has no legal standing - whether the OS map or a copy 
of the one-and-only definitive map (held by the Highway Authority and 
available for public inspection). Worse still, the "OS version" is the 
one version that still might be subject to copyright restrictions - 
although there is clearly an ongoing debate about the OS and PRoWs since 
the 1st April loosening of OS controls.

I understand and could support your categories (2) and (3).

I would add a category (4) that is not uncommon - especially in forested 
areas, in mountainous areas, on "open access" land etc. - the line of a 
path that conforms to the definitive (legal) line (and is usually also 
the line shown by the OS) that is physically unwalkable. There are a 
good number of examples near me where there is forest either with open 
access rights under the CROW Act or simply with permissive access rights 
- but the actual legal public rights of way are unwalkable (or virtually 
so) through dense undergrowth etc. It is not much of a practical issue 
as there are many alternative routes available in these forests - but 
how should we at OSM be mapping something like this. I have walked (or, 
rather, bushwhacked with considerable effort) my way through a number of 
them with GPS in hand - but am a bit reluctant to OSM-map them as paths 
- at least without some qualification to indicate that they are, for all 
practical purposes, unwalkable.

Personally, I would never argue with a farmer (or any landowner) based 
on OSM or even OS (far too many OS mapping errors - e.g. one of the most 
common is the path being shown on the side of a hedge line - perhaps on 
the wrong farmer's land - simply because of imperfect registration of 
the relevant GIS layers; and a normal hand-held GPS isn't going to be 
accurate enough either to determine reliably between two sides of a 
hedge or fence). I would always check the definitive map first (unless I 
had already done so in advance) - but having done that then I would feel 
able to defend the legal line and discuss solutions to anomalies.

So far as my own tagging on OSM is concerned, I always try to indicate 
(a) the source - usually 'GPS survey' - for the indicated line, (b) the 
physical nature of the way as observed in the field, (c) the legal 
status - if I know it - using the 'designation' tag with values of 
'public_footpath', 'public_bridleway', 'restricted_byway' or 'BOAT' (as 
an abbreviation for 'byway open to all traffic' - a misleading term as 
these are usually NOR open to ALL traffic - the law is complex). Where I 
am aware of a discrepancy with the OS-mapped line I will add a note to 
the effect that the OS mapping is wrong (giving the relevant date of the 
OS mapping of I can). Where I am aware of a discrepancy between the path 
on the ground and the definitive (legal) I also add a note to that 
effect. I support the idea of finding and agreeing a tagging practice 
that deals in some better way with the information that at present I 
simply include in 'note='.

Mike

On 19:59, Ian Spencer wrote:
> I think it would be useful to have a think about how we might tag 
> validated definitive ways in addition to the public footpath 
> recognising that there are potentially 3 different versions of a path:
>
> 1) The official published rights of way - say from OS.
> 2) OSM interpretation of rights of way (sourced from a combination of 
> survey, reinterpretation of LA data and OS data) which could differ. 
> (The difference between (1) & (2) is the to-do list with the LA 
> effectively)
> 3) The walkable paths which are considered by the public to be the 
> way, even if they are not the formal definition.
>
> While I wouldn't argue with a farmer based on OSM, if we knew what the 
> derivation was, and the status of any diversions, then at least you 
> can stride across that newly planted crop with a bit more confidence. 
> I don't think the current tagging regime exactly covers the above - 
> and I doubt there is great confidence in the legal validity of of a 
> footpath tagged in OSM as a Public Footpath.
>
> It seems to be that there should be a definitive-way tag with status 
> of yes, disputed, (and implicitly, no) and another of 
> definitive-way-source as you cannot establish a definitive way by GPS, 
> even though you can for the de facto line of the path (being able to 
> see the difference could be useful).
>
> Ian
>
>
> Andy Robinson (blackadder-lists) wrote on 13/05/2010 10:51:
>> Mike,
>>
>> A very comprehensive reply, thanks for that. It would be worth having 
>> what
>> you have written on a relevant wiki page as its probably the best 
>> write-up
>> of the arrangements as we know them.
>>
>> Cheers
>>
>> Andy
>>
>>> -----Original Message-----
>>> From: talk-gb-bounces at openstreetmap.org [mailto:talk-gb-
>>> bounces at openstreetmap.org] On Behalf Of Mike Harris
>>> Sent: 13 May 2010 9:06 AM
>>> To: talk-gb at openstreetmap.org
>>> Subject: Re: [Talk-GB] Talk-GB Digest, Vol 44, Issue 19
>>>
>>> Hi
>>>
>>> My understanding of PRoW law is that:
>>
>
>

-- 
*/Mike Harris/*
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