[closed] PRoW tagging (England & Wales)

I have a strong interest in this as cycle.travel carries out more detailed analysis of access tags than, I believe, any other end-user website.

I agree that it isn't reasonable for worldwide sites to parse E+W-specific values of the designation= tag (to my knowledge, cycle.travel is the only one that does).

However, it is widely understood and accepted that

1. highway= tags imply default access values;
2. these access values may vary from country to country.

This is why we moved away from tagging horse=yes on every single road back in 2006 (you can look it up in the lists if you like ;) ).

The international default is that highway=footway is restricted to pedestrians. This is also the case for 99% of country-specific values. A few places allow bikes under some circumstances and Brazil appears to allow mopeds. That's it.

Consequently it is clearly documented, and universally accepted, that there is no need to tag access=private on a footway to prevent motor vehicle access.

So these tags are unnecessary. A second question is whether they are wrong. In a technical sense, no, they aren't, for the reasons described by @AndyS.

In a community sense, however, intentionally breaking the visualisation used by the most popular renderers is antisocial at best and vandalism at worst. I would therefore expect that these tags should be removed and that such action, should it prove necessary (which I hope it won't), would be backed up by DWG.

As a postscript, @Sailor Steve, I think you would probably get a bit more sympathy if you could make your comments a little shorter and save us the moralising about "OSM will collapse under its own contradictions" and "loss of market confidence", which frankly just makes you look pompous.

OK - I'll try and provide some sort of answer to the several issues here. Whilst I suspect that it's really one for discussion on the talk-gb mailing list, I'll try and provide some answers to what I suspect are the key questions (and the answers to your previous question are also worth reading).

Question: Is it right or wrong to add "access=private" to a "highway=footway" that is a "designation=public_footpath" just because it runs across private land?

I'd argue that it would be irrelevant (and daft) to include a general access tag on a highway=footway unless there's some expectation locally that access other than foot might be allowed. Specifically, as you state, if something's a designated public footpath(4) then the landowner can't legally prevent foot access whenever they feel like it, so it's always going to be "foot=yes" (you can add that tag explicitly if you want - I often do - but actually it's implied by designation tag). The "runs across private land" thing is a complete red herring - you have legal access on foot.

Question: Is it right or wrong to add "access=private" to a "highway=track" that is a "designation=public_footpath"?

Here's where it gets interesting. If I see a "highway=track" in OSM in England and Wales with no access or designation tags at all I would not assume that public access (via any transport mode) was allowed - I'd put it into the "needs survey" bucket. It's highly likely (given the default of access in England and Wales) that there is no public access, but it's not certain either way.

If I see "designation=public_footpath" but no access tags; then like the footway above I know that there's an implied "foot=yes" so I do know that I have access on foot, but I don't know anything about other modes(1).

However, it's quite common for designated public footpaths to run along private farm tracks. Often there'll be a "private" sign to accompany the "public footpath" one. Here I'd suggest that an "access=private" tag is definitely justified (alongside "designation=public_footpath" and for clarification "foot=yes") to say that no, most transport modes aren't allowed but yes, foot access most definitely is.

Question: What about Public Bridleways?

They're similar to footpaths, except that the "designation=public_bridleway" implies "foot=yes", "horse=yes" and "bicycle=yes" (regardless of the rules for other traffic - there may still be a big "private" sign to keep out motor traffic). The "bicycle" part in no way indicates that it's passable by a cyclist on a normal road bike; just that they have a legal right to be there.

Question: ... and Restricted Byways?

Essentially as "public bridleways" but also allowing non-motorised vehicular traffic, so if you fancy a trip out in the coach and four, you're legally allowed to do so down a "designation=restricted_bridleway". Personally I'd also add the implied keys "foot=yes, bicycle=yes, horse=yes, vehicle=yes and (usually) motor_vehicle=no". The "motor_vehicle=no" part is usually needed in the parts of England that I tend to map because there's usually a sign excluding motor vehicle access to accompany the "restricted byway" sign (usually things are changed to "restricted byway" in order to explicitly exclude motor vehicle access). There is of course no guarantee that any particular non-motorised vehicle whill physically be able to get down a restricted byway.

Question: ... and a Byway Open to All Traffic?

The clue's in the name - this implies "motor_vehicle=yes" (i.e. you have a legal right to drive down there(2), along with other modes). Something signed as a "public byway" or just a "byway" is usually(3) a "Byway Open To All Traffic" ("BOAT").

Question: What does access=yes mean?

It means "whatever the sort of traffic that would normally allowed down here are". On a highway=footway it implies "foot=yes" not "motor_vehicle=yes". Your main dispute seems to be whether "access=private; foot=yes" or "access=yes" is correct on a "highway=footway" where foot access (and no other) is allowed. I'd argue that they both mean exactly the same thing ("foot=yes") and therefore you're both right. Personally, I'd just tag "foot=yes" here rather than "access=anything" - it'll cause less confusion. I'd also argue that it's also important to record the designation if it's a public footpath.

Question: What does access:foot=yes mean?

It probably means that the previous mapper was confused. I've always interpreted it as "foot=yes", but it's used by very few people in very few places.

Question: What about footpaths, bridleways and tracks that aren't designated as public footpaths, bridleways or byways, etc.?

Use access tags as best you can to describe the access rules that you know to be in force, based on your knowledge of the area. This might mean any one of a myriad of possible combinations - try and pick the best one based on what you see.

Question: Do any of the 5 map styles available on OpenStreetMap.org show England and Wales style footpath designations and access rights?

No.

Question: Would it make any sense of one of them did?

As things stand, not really - the osm.org styles all have to make sense internationally, and an English and Welsh public footpath rendering wouldn't even make sense across the whole of the UK.

Question: Would it be nice if someone ponied up the cash for some web hosting to host a tileserver that did show this?

Yes - feel free to contribute and organise. It'd have to be as a "local add-on" though.

Question: Do any "off the shelf" routers understand England and Wales style footpath designations?

Not that I'm aware of, though sanity in access tagging (saying "foot=yes" on footpaths and public tracks, omitting "access=private" when it is not needed etc.) will help greatly.

Question: How do I make my Garmin car satnav avoid dirt tracks that I don't want it to route down?

I find that removing them from the data before running mkgmap works for me. It does mean that you can't then use it for foot routing, but that's usually not an issue with a car satnav.

Question: I have a disagreement with another mapper. What's the best way to resolve it?

I'd start by trying to discuss it with them, and trying to understand each other's point of view. If that doesn't work, try the local mailing list (or forum, or facebook page, or whatever else your locality uses). If that doesn't work, try the OSMF Data Working Group(5). It's unlikely that the DWG will be able to wave a magic wand, but they'll at least be able to offer a view independent of the disagreeing parties.

Notes

Firstly - all of the above are my views, based on a fair bit of mapping of public rights of way in the last 7 years or so. There are different approaches taken (see for example SK53's answer to your previous question - a quick chat on talk-gb or #osm-gb will reveal that there are no certainties here). If there are takeaway messages from any of this it's "don't assume there are any certainties; alway do an on-the-ground survey of rights of way; always talk to other mappers to try and appreciate their point of view".

(1) bicycle is an interesting one here - there are people who'll argue that you have a right to cycle on public footpaths, but let's leave that to one side for now.

(2) in the absence of anything else preventing it, such as a traffic regulation order.

(3) I don't believe I can think of a single exception.

(4) in England and Wales - other countries have far more sane access rules.

(5) full disclosure - that currently includes me.

My understanding of access= is that it's a shorthand way of setting all the relevant modal access rights to the same value. You can then use individual modal keys to over-ride that default setting. access= is not supposed to be a summary of the overall access rights to a way.

So "access=private, foot=yes" implies a route that private to all modes apart from pedestrians, and it's the correct was of recording such rights.

Personally, when I'm tagging PRoWs, I usually only add the relevant positive modal values. So foot=yes for a Public Footpath, foot=yes, bicycle=yes, horse=yes for a Bridleway, etc. (Actually, I'll use designated in place of yes a lot of the time -- but that's an unnecessary complication for the present discussion.) I don't think there would be anything wrong with adding an access=private in addition to these tags, if the route is indeed private for all other relevant modes.

But I do think that adding the individual modal tags is necessary -- we don't really want to force routers and outer data users to have to know about the legal PRoW background in England and Wales, and know that designation=public_footpath etc implies some particular access tags. If each country did something like this, it would place an unreasonable burden on international projects. Also, if we were to do that, we'd then have the problem of whether or not the implied access tags over-ride ones that are given explicitly. e.g. is "designation=public_footpath, access=private" open to pedestrians and is "designation=byway_open_to_all_traffic, motor_vehicle=no" open to motor vehicles?

Disclaimer: It is my work that is being discussed in this question. I also consider it impolite that I was not invited to join the larger community discussion especially since I was happy to engage with Steve via PM.

"the mapper states this is because they have been established by easement and the landowner has a right to prevent access"

That is not strictly true. My point was that a public footpath only grants a right of way to pedestrians, not other forms of traffic. Following the conventions of OSM as described in the wiki access=private, foot=yes is the correct way to comprehensively describe which modes of transport can access a public footpath (and just as importantly which ones cannot).

Doesn't designation=public_footpath imply foot=yes?

I think it is unfair for us to assume that data consumers worldwide will be familiar with the intricacies of English rights of way. After all nobody would suggest that we should omit admin_level=10 from admin boundaries because it is implied by designation=civil_parish. It would also be necessary for any data consumer to check that the way in question is within the boundaries of England and Wales which might be a complex and costly operation.

"This results in ways losing their identity as footpaths or bridleways, being indistinguishable from genuine private ways on rendering used by OSM Standard, OSM Cycle Map & OSMAND"

The answer to this is to fix the data consumers rather than trying to remove valid data from the database. Displaying access details on the standard OSM rendering has always been a problem because we cater for many different transport types often with conflicting access permissions. Strictly speaking the current rendering is correct, provided you are a motorist.