[Talk-GB] National Cycle Network removal/reclassification

Andy Townsend ajt1047 at gmail.com
Fri Aug 14 14:49:04 UTC 2020


On 14/08/2020 14:53, David Woolley wrote:
> On 14/08/2020 12:46, Mateusz Konieczny via Talk-GB wrote:
>> If signage on the ground is gone or never existed then route relation 
>> should not be mapped in OSM*.
>
> In the long term, this could make OSM useless for motor traffic as 
> there is a general policy of decluttering signs.  One of the arguments 
> for that is that everyone uses satellite navigators, so they don't 
> need the signs.  I think is also used as an argument for why it can 
> take councils years to fix missing street name signs.
>
> If OSM relies on on the ground signage, when the authorities rely on 
> virtual signage in online maps, it could lose a lot of roads!


That's a bit of an "extrapolation too far" I think.  I don't think 
anyone was talking about general highway signage, just addressing the 
very real problem that happens when cycle routes change and signage 
lags, and the problems that we have when, on a route that goes A-B-C-D, 
Sustrans are no longer looking after the B-C part, but _everyone_ 
following the route will still need to get from B to C, so they'll have 
to "join up the gaps" between the Sustrans-maintained parts.

The key question is what Robert asked at the top of this thread:

 > We also might need to think about our tagging, as there will now be
 > more levels of routes: Full NCN routes, other promoted named routes
 > that aren't on the NCN.

... actually I'd add here a third category, where there are short gaps 
in existing Sustrans routes.  An example which I've mentioned elsewhere 
is https://www.openstreetmap.org/#map=17/54.23978/-1.20491&layers=C - 
Sustrans don't have NCN 656 running along the A170, there's a gap.

 > How can we distinguish these in OSM?
 > network=ncn and network=rcn are typically used for national and
 > regional level routes rather than specifically the Sustrans NCN.

I'd suggest that it makes no sense, in the case of the example above, to 
omit https://www.openstreetmap.org/way/38353700 from NCN 656.  This is 
what is in OSM now, and I think it makes sense to join the gap where 
there is unambiguously only one way of getting from A to B.  Perhaps 
some sort of role in the relation could be used here to say either "this 
isn't technically part of NCN656, but it's the only way of following 
NCN656, so you're going to have to go along here whether you like it or 
not".  Other "no longer Sustrans but still a promoted named route" 
sections could have a different relation role.

However I don't think that it makes sense to join up routes using any 
sort of guesswork.  Taking NCN 67 at 
https://www.openstreetmap.org/#map=11/53.2344/-1.3726&layers=C as an 
example - there's no point in pretending that it extends north of 
Corbriggs or south of Chesterfield.

Another problem is that the on-the-road updates may not match what 
Sustrans' new maps with dotted lines on them suggest that they will do.  
The NCN1 marker at 
https://www.openstreetmap.org/?mlat=54.30117&mlon=-0.44081#map=19/54.30117/-0.44081&layers=C 
has recently been "re-stickered" to remove the Sustrans logo.  As far as 
I can tell that road section isn't on the list to be made 
"non-Sustrans".  I have no idea whether Sustrans' web maps are wrong, 
Sustrans' volunteer has stickered the wrong sign, or (entirely possible) 
I've misread the intent of the re-stickering.

Best Regards,

Andy






More information about the Talk-GB mailing list