[Tagging] Lifecycle tag for preliminary ways or objects

[Andy Townsend]

On 26/12/2021 10:11, Dave F via Tagging wrote:
> On 26/12/2021 02:23, Timothy Noname wrote:
>> I've tried searching but cant find anything relevant.
>> Are there any conventions or proposals for tagging items for which 
>> there is some evidence but not conclusive evidence of its existence?
>>
>> For example looking at satellite imagery you can see a path that goes 
>> under some trees and a hedge and appears to come out the other side.
>
> Use the fixme tag. Many of the validators highlight such tags.
> https://wiki.openstreetmap.org/wiki/Key:fixme

Agreed - but I absolutely wouldn't use a regular "highway" tag on 
something that might not be a highway at all.  I'd suggest just a fixme 
tag with enough information in the value so that someone actually in the 
area can go and have a look.


>
>>
>> There are also many public footpaths marked on official maps that can 
>> be added using the osm website but definitely need to be checked on 
>> the ground as they might not be passable
>
> Being impassable, for various reasons, is not a reason to not map a UK 
> PROW in OSM.

Not knowing that whether it exists or not IS a reason not to map an 
England and Wales PROW in OSM as a regular highway type 
(highway=footway, highway=bridleway, highway=path, etc.).  First and 
foremost "highway=footway" etc. say "there is a path here", and then 
tags such as "designation" and access tags provide more details about 
the legal right of way.  Other than "just not adding it to OSM", 
probably the most common way of tagging "I know that there is a legal 
right of way here from other sources, but there is no path" is "highway=no":

https://overpass-turbo.eu/s/1ewh

example

https://www.openstreetmap.org/way/976779072

As an example of why it might be a bad idea, have a look at this bit of 
Jugger Howe Moor, in Yorkshire:

https://www.openstreetmap.org/#map=16/54.3795/-0.5609

The same area looks a bit clearer at

https://map.atownsend.org.uk/maps/map/map.html#zoom=15&lat=54.38033&lon=-0.55765

and there you can also turn on Richard's "UK PRoW" overlays.

Most of the public footpath that runs northwest / southeast there isn't 
visible on the ground, and actually doesn't fit the geography at all 
well.  Presumably 70 years or so ago someone in a council office drew a 
vague line on a map and thought to themselves "that'll do".  What public 
footpath signage there is at the western end is a bit vague and can just 
as easily refer to the southwest / northeast path as the other one.

It's all moorland, so you could have a go at walking along it (if it's 
been dry for a few months) - the Bing imagery shows where someone's had 
a go at that (actually well to the south of the alleged "public 
footpath"), but it'd be a gross misrepresentation to map either the 
vague line that Bing shows (but Maxar et al do not) or the alleged PRoW 
line as a "highway=footway" or similar.

As an aside, I've mapped https://www.openstreetmap.org/way/820187337 and 
other paths here with appropriate trail_visibility, sac_scale and 
surface values to try and let people know what they're letting 
themselves in for.

Best Regards,

Andy