Apologies for being slow to pick this one up. I was in private discussion with Andy on this using OSM messaging which appeared to have come to a conclusion. I now notice that it had moved to talk-gb.
For avoidance of doubt, all my edits have been fully manual. Here is the explanation I gave to Andy for using and preferring gb:national. I would be happy to hear from others on the matter. As you will notice this was worked out with PinkDuck up in Nofolk: Andy: "Regarding gb:national, I use that tag because that is what the sign says. gb:nsl_single and gb_nsl_dual are interpretations of the actual sign based on one's understanding of exactly what constitutes a dual carriageway which is not always clear. The Highway Code defines it as 'a dual carriageway is a road which has a central reservation to separate the carriageways.' I suggest that the status of divergent roads, very short sections on the approach to a roundabout and slip roads is uncertain and that the correct interpretation could only be agreed in a court. This is the conclusion that PinkDuck and I came to anyway. He asked the DfT of someone and learnt that trunk road slip roads were 60mph but that motorway ones were 70mph. etc etc. You will notice that I have corrected the limit on the roundabout to 60 mph." So...on the basis that we should tag what is there, we see a white sign with a black diagonal line on it then that is what we should indicate. We do of course interpret that by putting what we believe if the correct legal speed limit in maxspeed. As such a single carriageway national limit is coded as "maxspeed:type=gb:national,maxspeed=60 mph". As dual carriageway is tagged as "maxspeed:type=gb:national,maxspeed=70 mph". The motorway version is "highway=motorway,maxspeed:type=gb:national,maxspeed=70 mph". Thoughts? Regards, Peter Miller (PeterIto) On 23 September 2013 09:34, Philip Barnes <p...@trigpoint.me.uk> wrote: > On Sat, 2013-09-21 at 22:09 +0100, Andy Street wrote: > > I'd agree that maxspeed=national is insufficient as it is impossible > > to tell what speed you can do in a built up area. > National speed limits rarely apply in built up areas, other than > sometimes on faster feeder roads. The built up area limit in the UK is > 30mph, unless signposted differently. This is implied by the presence of > street lighting. 30mph limits, where there are no streetlights, require > repeater signs. > > > I'm also not a huge > > fan of the current practice of placing "single" or "dual" in the > > maxspeed:type tag either as I consider the number of carriageways to be > > feature of the road rather than the speed limit. > This tag is vital, as in the UK on roads where the national speed limit > applies, it is much more than a mere feature of the road as you put it, > but defines the speed limit. When roads change between single and dual > carriageway the speed limit changes, there are no signposts. > > 60 mph on single carriageways, 70 mph on dual carriageways or 70 mph on > motorways in England and Wales are never explicitly signposted on NSL > roads, but are indicated by the black diagonal, or motorway chopsticks > signs. > > There are a few exceptions on special roads, hence the A55 in North > Wales and the Edinburgh City Bypass do have 70mph signage. > > Phil (trigpoint} > > > _______________________________________________ > Talk-GB mailing list > Talk-GB@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-gb > -- Peter Miller CEO +44(0) 7774 667213 ITO World Ltd - Registered in England & Wales - Registration Number 5753174 Office - 2nd Floor, 25 Lower Brook Street, Ipswich, IP4 1AQ. Registered Office - 32 Hampstead Heath, London, NW3 1JQ. Telephone - 01473 272225 www.itoworld.com IMPORTANT: The contents of this email and any attachments are confidential. They are intended for the named recipient(s) only. If you have received this email in error, please notify the system manager or the sender immediately and do not disclose the contents to anyone or make copies thereof.
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