I was thinking of asking on sabre. Am especially puzzled by the slip road situation. Tomtom does drop the limit to 60 on slip roads, which I had always assumed is an error. One place I have noticed it recently is going from the A41 to the A55 westbound near Chester. At some point, before the traffic joins warning signs it drops its limit to 60. At what point are you supposed to assume you are no longer on a dual-carriageway?
Phil -- Sent from my Nokia N9 On 01/10/2012 20:48 Brian Prangle wrote: How about making contact with the road experts at SABRE to answer some of these questions? I'm sure they'd have a pretty definitive view Regards Brian On 30 September 2012 22:43, Peter Miller <[email protected]> wrote: On 27 September 2012 17:42, Jason Cunningham <[email protected]> wrote: As I mentioned earlier on it was speed limits for roundabouts along a dual carriageway that led to me doing a bit of research on UK speed limit legislation. My 'notes' are below http://wiki.openstreetmap.org/wiki/User:Jamicu/UK_Speed_Limits A roundabout does not meet the given definition of a dual carriageway provided by legislation, and therefore is classified as a single carriageway road. Therefore a NSL roundabout can either be a NSL Restricted road or NSL single carriageway road speed limit. Recently spotted that my satnav already new this. That does make sense. Slip road connected to dual carriageways also does not meet the definition of a dual carriageway. Slip roads on motorways are not covered by NSL legislation. The whole motorway network, which includes the slip roads, is deliberately outside NSL legislation. Motorways are "special roads" with separate legislation. If the slips roads are part of the Motorway Network then they're "special roads" covered the Motorway Legislation with a maxspeed for cars of 70 mph. Thanks for the clarification. So what about slip roads on non-motorway dual-carriageways? Are these 70mph or 60mph in your view? Things can be different in Scotland. I concentrated on reading 'English' legislation and case law. Having read legislation and case law I'm happy to argue that British speed limit law is a mess. Once you understand the foibles of the legislation you'll start spotting stretches of road where signs are wrong or missing. The link below shows locations of street lighting around a junction. http://goo.gl/maps/I8uhr (yellow for lighting for main road, and orange for lighting of runabout which is technically a separate section of road.) There are clearly sections of road with 3 more street lamps that mean that unless otherwise signed the stretches of road are 'NSL Restricted' with speed limits for cars of 30mph. Roads leading up to the lighting are NSL single carriageway with speed limits cars of 60 mph. Legislation states there should be signs clearly advising you that NSL Restricted begins or small signs reminding you NSL single lane carries on, but they are missing (I haven't spotted nsl signs while driving or when double checking today using StreetView). Therefore the speed limit defaults to NSL Restricted. Since drivers would expect a sign for a change in speed limit they are unlikely to slow down to the NSL Restricted speed limit. Lack of signs for any other change in speed limit would mean it would be impossible to prosecute, but signs are not needed for NSL Restricted road and there is case law to support this. A problem for drivers, and for people trying to map speed limits. I believe that when one starts finding errors on the ground it is a good indicator that you are getting good at what you are doing! Putting aside my little rant about missing speed limit signs, I think we could do with proper page giving some advice of speed limits if we intend to map them. Or just roll the details into the speed limits or maxspeed articles for now as the same sort of questions are likely to appear in other countries? Thanks, Peter Jason _______________________________________________ Talk-GB mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-gb _______________________________________________ Talk-GB mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-gb
_______________________________________________ Talk-GB mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-gb
