[Talk-GB] Refs on Tertiary & Unclassifed Roads in Highland

Robert Whittaker (OSM lists) robert.whittaker+osm at gmail.com
Sun Mar 17 19:02:22 UTC 2013


On 17 March 2013 09:54, sk53.osm <sk53.osm at gmail.com> wrote:
> I've noticed that many minor roads in the Highland Region of Scotland have
> been tagged with ref=[CU]#### based on a PDF document from the regions
> transport department. I've altered a few of these where I've encountered
> them to official:ref=* as I don't believe that these are verifiable on the
> ground in any way.
>
> I'd be interested in what others think (these council based refs do appear
> elsewhere in the country: I can't recall ever seeing one on a road sign).

I don't think whether or not the reference numbers appear on signs is
relevant at all. If the road has an official reference number "C616"
(and it can be verified it in some way) then I don't why that
shouldn't be tagged using the key that's designed for primary official
reference numbers, i.e. ref=C616.

I would say that altering our tagging to avoid these numbers appearing
on maps or in directions is to a large extent tagging for the render /
router. The reference number *is* C616. Whether or not a map or router
chooses to use that is something for the map or router to decide. Yes
it will be hard to make these decisions at times, and maybe the OSM
data should contain hints, but I'm not sure altering how we store the
reference number is the best way to help.

I would imagine that there are also going to be lots of cases of rural
road with names where the name is well known to locals (and the
postman) but is never actually signed anywhere. (Typically the road
leaving one village and heading for the next will be named after the
village it is heading to, but there may not be any signs to that
effect.) Should we also not put this name in the name tag, because it
isn't signed with that name on the ground, and routers using the name
will confuse their users?

I don't think there's any getting away from having good routers /
navigation software adopting country-specific rules for how to
describe different classes of road to users. For any cases where we
may need to deviate from these country-defaults, perhaps we need a tag
that describes what the road is or is not signed as on the ground.

(If you really want to do navigation well, you would need to know what
each road is signed as at each junction. On UK road signs outside
residential areas, it's usually the major destination that's signed at
junctions with a road number for A and B roads, rather than a name. So
simply removing C and U reference numbers won't actually help that
much. Users of navigation software would then either get an equally
confusing name or nothing, rather than what is actually written on the
sign at the junction.)

Robert.

-- 
Robert Whittaker



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