Re: [Talk-GB] Relation for M5?
Colin Smale wrote: > * there are lots of stretches of roads with (ostensibly) two UK > numbers (segment is shared between two routes) Nope - there aren't. That's a popular misconception. Where (for example) the A11 "disappears" into the A14 east of Cambridge, for example, the road really is only the A14. It isn't the A11 at all, though the signposts may say A14 (A11) to guide you to the place where the A11 resumes. You can ask over on sabre-roads.org.uk if you don't believe me. :) This is different from the practice in the US, where the road will take both numbers. But it wouldn't work in the UK. The M40 north of Bicester, for example, would end up being the M40, A34 and A41 at the same time... > * E-routes forming a network which overlays the national network > * well-known routes like "South Circular" which are made from bits > of lots of different roads Will happily grant you those two :) , though I don't think that's what Dave was referring to in his original post. > * roads such as the A1 which are part motorway with a different ref - > an "A1" relation could be continuous from London to Edinburgh Hmmm. Not sure about that. The A1(M) isn't the A1 - it's the A1(M). In some cases, both the motorway and the original road exist side-by-side, as with the A3(M) and the A3. Regardless, if you want to fetch both at the same time, you can still use a similar pseudo-query to the one I posted earlier: a relation is a needless duplication of data and just increases the burden for mappers. cheers Richard -- View this message in context: http://gis.638310.n2.nabble.com/Relation-for-M5-tp6872139p6872913.html Sent from the Great Britain mailing list archive at Nabble.com. ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Relation for M5?
On 08/10/2011 16:42, Richard Fairhurst wrote: In the UK, each road can only belong to one route (i.e. an unambiguous ref= tag). There is no need for road route relations; the M5 motorway is more easily defined as "all ways within the UK bounding box with the tags highway=motorway* and ref=M5". Consequently we don't use road route relations in the UK. That's a bit of a sweeping statement! I can think of several cases when they would be useful: * there are lots of stretches of roads with (ostensibly) two UK numbers (segment is shared between two routes) * E-routes forming a network which overlays the national network * well-known routes like "South Circular" which are made from bits of lots of different roads * roads such as the A1 which are part motorway with a different ref - an "A1" relation could be continuous from London to Edinburgh --colin ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Relation for M5?
Maybe the wiki should be updated ? However, I think route relations are quite extensive across the UK. I first came across them on the A1 but I'm fairly confident lots of other roads have them on. I'm a fan of consistency so if we remove the M5 one then we should remove the others as well. This would make the UK more consistent (within the UK) and would ensure people don't have an example to copy from. As an aside: I've seen some external sites link to the relations. I've seen things saying this shouldn't be done, but that hasn't stopped people doing it in practice. Deleting the relations would break those links. On 08/10/2011 15:42, Richard Fairhurst wrote: Mark S wrote: > Looking at the wiki (route=road) it seems to suggest a relation can > be used here. Road route relations are useful in the US, and some other countries, where a section of road can belong to two routes. In the UK, each road can only belong to one route (i.e. an unambiguous ref= tag). There is no need for road route relations; the M5 motorway is more easily defined as "all ways within the UK bounding box with the tags highway=motorway* and ref=M5". Consequently we don't use road route relations in the UK. cheers Richard ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Relation for M5?
Mark S wrote: > Looking at the wiki (route=road) it seems to suggest a relation can > be used here. Road route relations are useful in the US, and some other countries, where a section of road can belong to two routes. In the UK, each road can only belong to one route (i.e. an unambiguous ref= tag). There is no need for road route relations; the M5 motorway is more easily defined as "all ways within the UK bounding box with the tags highway=motorway* and ref=M5". Consequently we don't use road route relations in the UK. cheers Richard -- View this message in context: http://gis.638310.n2.nabble.com/Relation-for-M5-tp6872139p6872600.html Sent from the Great Britain mailing list archive at Nabble.com. ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Relation for M5?
Looking at the wiki (route=road) it seems to suggest a relation can be used here. However, it stikes me that the relation should be more than just the roads without a role. The wiki suggests the road itself would have a forward/backward role, and that link roads should be in the relation (the link roads are still motorway standard and are referred to as M5 link roads). I'd have also thought that in the ideal world the junctions and services would be in the relation as well. That way you can get everything to do with the M5 and create things such as a line diagram showing the M5 and all its junctions (which would be hard to do without a relation). Mark S PS: I have to declare an interest here in that I might have touched this in the past to complete an initial partial relation. On 08/10/2011 10:35, Dave F. wrote: Hi Anyone know why has the M5 motorway got a route relation dedicated to it? Route relations are meant to represent, err... routes taken by people that transverse multiple different ways; such as bus cycle etc & not just a 'collection' of things. This has lead to tag duplication which can never be a good thing. Dave F. ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
[Talk-GB] Relation for M5?
Hi Anyone know why has the M5 motorway got a route relation dedicated to it? Route relations are meant to represent, err... routes taken by people that transverse multiple different ways; such as bus cycle etc & not just a 'collection' of things. This has lead to tag duplication which can never be a good thing. Dave F. ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
