Re: [Talk-GB] National speed limit changes
On 30 September 2013 08:12, Peter Miller peter.mil...@itoworld.com wrote: On 29 September 2013 10:05, Colin Smale colin.sm...@xs4all.nl wrote: How about saying that 70mph can only be valid on a way tagged as one-way? In a word, I believe the answer is 'no'. I say that because the legal definition of a dual-carriageway appears to be vague, with unclear edge-cases. There are certainly examples of one-way national speed limit trunk and primary roads which are not 70 mph. But that's not what Colin was saying. He was suggesting, 70mph implies one-way, not one-way implies 70mph. Or to put it another way, he was saying 70 is not allowed on a two-way road rather than a one-way road must be 70. It is for these reasons that I advocate setting maxspeed:type simply to 'GB:national' and then interpretting it to the best of our current knowledge as a numeric limit in maxspeed. Possibly we should err on the side of caution with the numeric limit. In that case, surely it is better to make use of the more definite tags GB:nsl_single and GB:nsl_dual when we are sure of the type of road (which will be the majority of cases), and only use GB:national for the cases where we aren't sure. (Ok, so you can work out which is implied by looking at the maxspeed value, but that's additional work for data users, and means that it's less clear how the mapper has come to their maxspeed conclusion. Also, with your suggestion of caution on unclear cases, there would be no way to distinguish between a definite single carriageway road and the unsure situation, since both would use maxspeed=60pmh and maxspeed:type=GB:national.) On 27 September 2013 15:40, Peter Miller peter.mil...@itoworld.com wrote: Based on that, where you've changed e.g. GB:nsl_single to gb:national would it be possible for you to revert your changes? There's clearly a discussion to be had going forward about which one of GB:blah, UK:blah, gb:blah and uk:blah we need to keep, but based on the replies so far there doesn't appear to be a concensus to support merging of everything into gb:national. I don't hear a clamoring for such a reversion, and indeed I don't think anyone in OSM is sufficiently knowledgeable able the law to say for sure which tag should be used in all cases as I have indicated above. If there have been bulk changes from more specific things like GB:nsl_single to the more general GB:national, then I have already said in a previous message that I think those changes should be reverted. There had been no previous discussion or agreement about making the changes (which is reason in itself for reverting), and there still doesn't appear to be a consensus. Also, it's arguably loosing information (whether it's right or wrong) captured by the original mapper. In almost all cases it will be obvious whether a road is a dual carriageway or not. I don't believe the few edge cases warrant removing the majority of good information. Robert. -- Robert Whittaker ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] National speed limit changes
On 2 October 2013 10:15, Robert Whittaker (OSM lists) robert.whittaker+...@gmail.com wrote: On 30 September 2013 08:12, Peter Miller peter.mil...@itoworld.com wrote: On 29 September 2013 10:05, Colin Smale colin.sm...@xs4all.nl wrote: How about saying that 70mph can only be valid on a way tagged as one-way? In a word, I believe the answer is 'no'. I say that because the legal definition of a dual-carriageway appears to be vague, with unclear edge-cases. There are certainly examples of one-way national speed limit trunk and primary roads which are not 70 mph. But that's not what Colin was saying. He was suggesting, 70mph implies one-way, not one-way implies 70mph. Or to put it another way, he was saying 70 is not allowed on a two-way road rather than a one-way road must be 70. I see what you mean. I agree than one could use the 70mph/not one way pair as an indicator that either a one-way tag is missing or that the 70 is in error. It is for these reasons that I advocate setting maxspeed:type simply to 'GB:national' and then interpretting it to the best of our current knowledge as a numeric limit in maxspeed. Possibly we should err on the side of caution with the numeric limit. In that case, surely it is better to make use of the more definite tags GB:nsl_single and GB:nsl_dual when we are sure of the type of road (which will be the majority of cases), and only use GB:national for the cases where we aren't sure. (Ok, so you can work out which is implied by looking at the maxspeed value, but that's additional work for data users, and means that it's less clear how the mapper has come to their maxspeed conclusion. Also, with your suggestion of caution on unclear cases, there would be no way to distinguish between a definite single carriageway road and the unsure situation, since both would use maxspeed=60pmh and maxspeed:type=GB:national.) Agreed. Fyi, Ed Loach has just emailed me with a load of analysis of where 'dual carriageway' signs are used and should be used. I suggest we may also want to make more use of a separate tag associated with those signs. I have encouraged him to post this to the list, although he had a technical error with posting to the list a few days ago. On 27 September 2013 15:40, Peter Miller peter.mil...@itoworld.com wrote: Based on that, where you've changed e.g. GB:nsl_single to gb:national would it be possible for you to revert your changes? There's clearly a discussion to be had going forward about which one of GB:blah, UK:blah, gb:blah and uk:blah we need to keep, but based on the replies so far there doesn't appear to be a concensus to support merging of everything into gb:national. I don't hear a clamoring for such a reversion, and indeed I don't think anyone in OSM is sufficiently knowledgeable able the law to say for sure which tag should be used in all cases as I have indicated above. If there have been bulk changes from more specific things like GB:nsl_single to the more general GB:national, then I have already said in a previous message that I think those changes should be reverted. There had been no previous discussion or agreement about making the changes (which is reason in itself for reverting), and there still doesn't appear to be a consensus. Also, it's arguably loosing information (whether it's right or wrong) captured by the original mapper. In almost all cases it will be obvious whether a road is a dual carriageway or not. I don't believe the few edge cases warrant removing the majority of good information. There has not been any bulk changes to my knowledge. I for one have not done any, and this is not the first time in this thread that I have had to clarify that I have not done so, can we now drop this suggestion please. To be clear, I have been moved some gb:national style tagging from source:maxspeed to macspeed:type to allow source:maxspeed to be used for information about the data gathering process and may have simplified with to GB:national in the process (apologies), but I have not done any bulk or mechanical edits - every change has been manual and associated with adding speed limit data in a neighbouring area. Peter Robert. -- Robert Whittaker ___ 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
Re: [Talk-GB] National speed limit changes
On 29 September 2013 10:05, Colin Smale colin.sm...@xs4all.nl wrote: ** Peter, I say this because the '70 mph' value for maxspeed can only be used case where a road is a dual-carriageway. What about link roads and slip roads? Sometimes they seem to go on for miles without an obvious other carriageway. Yet the correct maxspeed is often 70mph, is it not? How about saying that 70mph can only be valid on a way tagged as one-way? In a word, I believe the answer is 'no'. I say that because the legal definition of a dual-carriageway appears to be vague, with unclear edge-cases. There are certainly examples of one-way national speed limit trunk and primary roads which are not 70 mph. Possibly it would be best to discuss some actual situations. How about Junction 31 on the A14 junction to the west of Cambridge. Most slip roads are currently 60 mph, but one is 70 mph. A short section of parallel ways of the Huntingdon Road is shown as 70 mph however I am not now clear if that short section constitutes a dual carriageway. http://www.itoworld.com/map/124?lon=0.07067lat=52.23321zoom=15fullscreen=true How about the many short sections of 'dual-carriagway' on the A120 in Essex such as this one. Dual carriageway or not? I am not clear. http://www.itoworld.com/map/124?lon=1.21929lat=51.92823zoom=17fullscreen=true Or this junction between the M1 and A421. Again, short sections of 'dual-cariageway' and slip roads to both a motorway and a trunk road. What is their status? http://www.itoworld.com/map/124?lon=-0.60951lat=52.02764zoom=16fullscreen=true It is for these reasons that I advocate setting maxspeed:type simply to 'GB:national' and then interpretting it to the best of our current knowledge as a numeric limit in maxspeed. Possibly we should err on the side of caution with the numeric limit. Regards, Peter Colin On 2013-09-29 10:14, Peter Miller wrote: To attempt to summarise the situation: - The maximum legal speed for any vehicle should be a number in maxspeed following by mph. - There should also be information available to say if this speed is defined as a number in a circle or a black and white sign - There is also benefit, for various reasons, to know if a road is single carriageway or dual carriageway. - There also seems to be agreement (in the form of silence from some) that there is no clear definition of what is and is not a dual-carriageway in the UK without going to court! - OSM tagging policy is generally that one should tag what one sees. As such, it seems unreasonable to ask a new mapper to great a situation requiring a court case for every ambiguous section of road in the country to establish if they are dual carriageways or single carriageways. This is why I suggest we use GB:national to indicate that the speed is set by a black/white sign. We could however compromise and suggest 'GB:nsl_dual' where we know if is a dual carriageway, 'GB:nsl:single' where we know it isn't and GB:national where we aren't sure. Alternatively, we could always use 'GB:national' for the maxspeed type and add other tagging to indicate dual carriagewayness, either using 'carriagway=A/B' tag or a relation with type=dual-carriageway or similar. Or.. and this is the simplest approach in the short term as far as I can see which I have been advocating, we can imply dual-carriagewayness by a combining a highway tag with the tag pairs 'maxspeed=70' and 'maxspeed:type=GB:national'. I say this because the '70 mph' value for maxspeed can only be used case where a road is a dual-carriageway. As we get clearer about what constitutes a dual-carriageway or not we then only need to change with speed between 70 mph to 60 mph. We can then also populate approach dual-carriageway tagging on these roads. Regards, Peter On 29 September 2013 00:45, Nick Allen nick.allen...@gmail.com wrote: Peter, After your first post on this, my initial thought was that you were correct and the simpler tag you were proposing was enough. I started following your proposal, but I've thought a little more feel that the more involved 'GB:nsl_single' type tag is actually needed I'll be going back through my work over the last couple of days and changing it back. My thinking is; i/. The basis of GB law is that it is up to the individual to know what the law states, and to comply with it. No matter what your SatNav tells you it won't help you when you are standing in a court explaining your actions - the SatNav is a guide only and some maintain that they are unsafe as they distract the driver who may therefore miss the speed limits being displayed. ii/. If you are driving a motor vehicle with very few exceptions you should comply with the law regarding speed limits. iia/. A built up area with street lighting (I'm not entirely sure how you define built up area, and I seem to remember something about the street lights being no more than 200
Re: [Talk-GB] National speed limit changes
Peter, I say this because the '70 mph' value for maxspeed can only be used case where a road is a dual-carriageway. What about link roads and slip roads? Sometimes they seem to go on for miles without an obvious other carriageway. Yet the correct maxspeed is often 70mph, is it not? How about saying that 70mph can only be valid on a way tagged as one-way? Colin On 2013-09-29 10:14, Peter Miller wrote: To attempt to summarise the situation: * The maximum legal speed for any vehicle should be a number in maxspeed following by mph. * There should also be information available to say if this speed is defined as a number in a circle or a black and white sign * There is also benefit, for various reasons, to know if a road is single carriageway or dual carriageway. * There also seems to be agreement (in the form of silence from some) that there is no clear definition of what is and is not a dual-carriageway in the UK without going to court! * OSM tagging policy is generally that one should tag what one sees. As such, it seems unreasonable to ask a new mapper to great a situation requiring a court case for every ambiguous section of road in the country to establish if they are dual carriageways or single carriageways. This is why I suggest we use GB:national to indicate that the speed is set by a black/white sign. We could however compromise and suggest 'GB:nsl_dual' where we know if is a dual carriageway, 'GB:nsl:single' where we know it isn't and GB:national where we aren't sure. Alternatively, we could always use 'GB:national' for the maxspeed type and add other tagging to indicate dual carriagewayness, either using 'carriagway=A/B' tag or a relation with type=dual-carriageway or similar. Or.. and this is the simplest approach in the short term as far as I can see which I have been advocating, we can imply dual-carriagewayness by a combining a highway tag with the tag pairs 'maxspeed=70' and 'maxspeed:type=GB:national'. I say this because the '70 mph' value for maxspeed can only be used case where a road is a dual-carriageway. As we get clearer about what constitutes a dual-carriageway or not we then only need to change with speed between 70 mph to 60 mph. We can then also populate approach dual-carriageway tagging on these roads. Regards, Peter On 29 September 2013 00:45, Nick Allen nick.allen...@gmail.com wrote: Peter, After your first post on this, my initial thought was that you were correct and the simpler tag you were proposing was enough. I started following your proposal, but I've thought a little more feel that the more involved 'GB:nsl_single' type tag is actually needed I'll be going back through my work over the last couple of days and changing it back. My thinking is; i/. The basis of GB law is that it is up to the individual to know what the law states, and to comply with it. No matter what your SatNav tells you it won't help you when you are standing in a court explaining your actions - the SatNav is a guide only and some maintain that they are unsafe as they distract the driver who may therefore miss the speed limits being displayed. ii/. If you are driving a motor vehicle with very few exceptions you should comply with the law regarding speed limits. iia/. A built up area with street lighting (I'm not entirely sure how you define built up area, and I seem to remember something about the street lights being no more than 200 yards apart) will have a speed limit of 30 mph unless there are signs indicating otherwise, there should be repeater signs at intervals if it is not a 30mph area. iib/. National speed limit signs - the national speed limit has changed during my lifetime. Motorways are fairly simple, and for a car (not towing) it will be 70mph. Two-way roads with a national speed limit sign are also fairly simple, being 60mph for a car (not towing). Dual carriageways - little bit more complex - an island in the middle of the road to assist pedestrians to cross is not sufficient to make it a dual carriageway, but you would need to look at the current case law to help in deciding what exactly is a dual carriageway. I don't think a long length of wide road with the lanes divided by white crosshatch markings on the road, even if this exists for a length measured in miles, counts as a dual carriageway - it needs to have a physical barrier involved. iiic/. A prescribed limit indicated by signs such as '40', '50' etc.. iii/. The current software writers who seem to be using OSM data are mainly wrestling with the basics of navigating a car anywhere in the world but I think steps are being made towards navigation for larger vehicles, and these vehicles are likely to have different speed limits imposed on them in GB national speed limit areas. If they are writing software for navigating a 40 tonne lorry across Europe then the least we can do
Re: [Talk-GB] National speed limit changes
Peter, After your first post on this, my initial thought was that you were correct and the simpler tag you were proposing was enough. I started following your proposal, but I've thought a little more feel that the more involved 'GB:nsl_single' type tag is actually needed I'll be going back through my work over the last couple of days and changing it back. My thinking is; i/. The basis of GB law is that it is up to the individual to know what the law states, and to comply with it. No matter what your SatNav tells you it won't help you when you are standing in a court explaining your actions - the SatNav is a guide only and some maintain that they are unsafe as they distract the driver who may therefore miss the speed limits being displayed. ii/. If you are driving a motor vehicle with very few exceptions you should comply with the law regarding speed limits. iia/. A built up area with street lighting (I'm not entirely sure how you define built up area, and I seem to remember something about the street lights being no more than 200 yards apart) will have a speed limit of 30 mph unless there are signs indicating otherwise, there should be repeater signs at intervals if it is not a 30mph area. iib/. National speed limit signs - the national speed limit has changed during my lifetime. Motorways are fairly simple, and for a car (not towing) it will be 70mph. Two-way roads with a national speed limit sign are also fairly simple, being 60mph for a car (not towing). Dual carriageways - little bit more complex - an island in the middle of the road to assist pedestrians to cross is not sufficient to make it a dual carriageway, but you would need to look at the current case law to help in deciding what exactly is a dual carriageway. I don't think a long length of wide road with the lanes divided by white crosshatch markings on the road, even if this exists for a length measured in miles, counts as a dual carriageway - it needs to have a physical barrier involved. iiic/. A prescribed limit indicated by signs such as '40', '50' etc.. iii/. The current software writers who seem to be using OSM data are mainly wrestling with the basics of navigating a car anywhere in the world but I think steps are being made towards navigation for larger vehicles, and these vehicles are likely to have different speed limits imposed on them in GB national speed limit areas. If they are writing software for navigating a 40 tonne lorry across Europe then the least we can do is try to indicate what type of road it is so they can attempt to give an indication to the driver of what is the maximum speed they may legally travel at. Regards Nick (Tallguy) Hi Peter, Thanks for replying here. Peter Miller wrote: 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. I understand the potential problem (does a national speed limit dual carriageway slip road count as a dual carriageway or not?) but am concerned that changing e.g. GB:nsl_single to gb:national will: o potentially obscure any underlying data errors (imagine something tagged maxspeed=70 mph, maxspeed:type=GB:nsl_single) o make things more difficult for data consumers (if only by changing the data from something that they might be expecting) o confuse new mappers who see data that they've entered being changed because it's wrong, when in reality there really isn't a concensus on this. I fully accept that national speed limit tagging in the UK is a mess (at the time of writing 4 of the top 6 values for http://taginfo.openstreetmap.org.uk/keys/maxspeed:type#values could mean the same thing) but any consolidation must proceed following discussion. Sure, and I am politely inviting people to discuss the subject now and am suggesting that it makes a lot of sense to consolidate around a tag value which describes what one sees in front of one on the ground, ie a black and white sign. To be clear I in the habit of using the nsl_single and nsl_dual format until PinkDuck politely pointed out that I was tagging some slip-road etc incorrectly and we agreed that is made more sense to avoid the confusion in the first place and use the simpler gb:national. With regard to the other point: For avoidance of doubt, all my edits have been fully manual. I don't believe that anyone has suggested otherwise I was responding to Roberts comment above that I certainly don't think there has been any discussion of or agreement for a mass mechanical edit to change existing values. although I
Re: [Talk-GB] National speed limit changes
The subject of UK speed limits and problems of mapping them has come up a couple of times on these lists. Firstly we have a problem because many users want a single numerical value in the maxspeed tag, despite UK legislation having a range of speed limits for road dependent on the physical nature of the road. Secondly our Speed Limit legislation is an utter mess, with poor simplified guidance that confuses people. I suppose you can argue that our problems with tagging speed limits is appropriate because it mirrors the mess that is our speed limit legislation. Last year, when I was a bit more active in OSM, I wrote up all my notes on Speed Limits on my OSM wiki page. https://wiki.openstreetmap.org/wiki/User:Jamicu/UK_Speed_Limits Worth reading because a few posts before show some people are making perfectly understandable but incorrect conclusions about speed limits eg 1 On 21 September 2013 22:09, Andy Street m...@andystreet.me.uk wrote: 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. Regards, Andy Street Single or Dual refer to two of our three national speed limit types. NSL speed limits are created by the physical nature of the road and *not*signs. Dual Single are definitely a feature of the speed limit. eg 2 On 23 September 2013 09:34, Philip Barnes p...@trigpoint.me.uk wrote: 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. Phil (trigpoint} National speed limits nearly always apply in built up areas. The 30mph 'built up area limit' you refer to is the third type of NSL, the NSL Restricted road type. Along side the other two NSL's it is created by the physical nature of the road and *not* signs. But getting to the main point, the use of maxspeed:type=national I strongly disagree with removing data which tells us the type of speed limit and replacing it with a word that implies 1 of 3 types of speed limit is in place. It's useful information and more importantly it's the correct information. I'm not sure if this is actually the case here though? Peter, you argue that your mapping what's on the sign? But the signs do not create the speed limit for a NSL road, its the physical features of the road that create the NSL type. That means '*System of Street Lighting*', '*oncoming traffic separated by barrier*', but if neither of the previous applies the road is 'single carriageway NSL' Personally, I think having two tags is bad practice, and that we should remove the numerical value from the maxspeed tag and replace it with the correct speed limit type. End users should then use a table to get the speed limit for the vehicle they're interested in. I accept its a complex subject and I accept average users of OSM will find it easier to simply type in the maxspeed for cars, but the more confident users of OSM should be seeking to improve data, and not strip it out. Having access to NSL types is very useful especially when we hear about plans to change speed limits. Jason ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] National speed limit changes
Routers cannot be expected to know the intricacies of every countrys spotted limit legislation, it would therefore be wrong to remove the default car/motorcycle speed limits. Vehicles to which other limits apply are usually driven by professionals and should therefore be using specialist tools, which do take onto account the type of vehicle. Routers in my opinion, over use road classification and seen to assume that trunk is some sort of expressway, which in most cases they aren't. Primaries, B roads and tertiarys, many of which are declassified trunk are just as quick, often quicker as they take a shorter route. Phil (trigpoint) -- Sent from my Nokia N9 On 26/09/2013 12:37 Jason Cunningham wrote: The subject of UK speed limits and problems of mapping them has come up a couple of times on these lists. Firstly we have a problem because many users want a single numerical value in the maxspeed tag, despite UK legislation having a range of speed limits for road dependent on the physical nature of the road. Secondly our Speed Limit legislation is an utter mess, with poor simplified guidance that confuses people. I suppose you can argue that our problems with tagging speed limits is appropriate because it mirrors the mess that is our speed limit legislation. Last year, when I was a bit more active in OSM, I wrote up all my notes on Speed Limits on my OSM wiki page. https://wiki.openstreetmap.org/wiki/User:Jamicu/UK_Speed_Limits Worth reading because a few posts before show some people are making perfectly understandable but incorrect conclusions about speed limits eg 1 On 21 September 2013 22:09, Andy Street m...@andystreet.me.uk wrote: 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. Regards, Andy Street Single or Dual refer to two of our three national speed limit types. NSL speed limits are created by the physical nature of the road and not signs. Dual Single are definitely a feature of the speed limit. eg 2 On 23 September 2013 09:34, Philip Barnes p...@trigpoint.me.uk wrote: 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. Phil (trigpoint} National speed limits nearly always apply in built up areas. The 30mph 'built up area limit' you refer to is the third type of NSL, the NSL Restricted road type. Along side the other two NSL's it is created by the physical nature of the road and not signs. But getting to the main point, the use of maxspeed:type=national I strongly disagree with removing data which tells us the type of speed limit and replacing it with a word that implies 1 of 3 types of speed limit is in place. It's useful information and more importantly it's the correct information. I'm not sure if this is actually the case here though? Peter, you argue that your mapping what's on the sign? But the signs do not create the speed limit for a NSL road, its the physical features of the road that create the NSL type. That means 'System of Street Lighting', 'oncoming traffic separated by barrier', but if neither of the previous applies the road is 'single carriageway NSL' Personally, I think having two tags is bad practice, and that we should remove the numerical value from the maxspeed tag and replace it with the correct speed limit type. End users should then use a table to get the speed limit for the vehicle they're interested in. I accept its a complex subject and I accept average users of OSM will find it easier to simply type in the maxspeed for cars, but the more confident users of OSM should be seeking to improve data, and not strip it out. Having access to NSL types is very useful especially when we hear about plans to change speed limits. Jason ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] National speed limit changes
On 26 September 2013 12:59, Philip Barnes p...@trigpoint.me.uk wrote: Vehicles to which other limits apply are usually driven by professionals I'd wager that far more cars-towing-caravans are driven by amateurs than professionals. -- Andy Mabbett @pigsonthewing http://pigsonthewing.org.uk ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] National speed limit changes
Philip Barnes phil@... writes: Routers in my opinion, over use road classification and seen to assume that trunk is some sort of expressway, which in most cases they aren't. Primaries, B roads and tertiarys, many of which are declassified trunk are just as quick, often quicker as they take a shorter route. Phil (trigpoint) This is a structural problem with the OSM database caused by the same tag being used with two distinct meanings in different countries. It would be good to get to the bottom one day. -- Andrew ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] National speed limit changes
Hi Peter, Thanks for replying here. Peter Miller wrote: 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. I understand the potential problem (does a national speed limit dual carriageway slip road count as a dual carriageway or not?) but am concerned that changing e.g. GB:nsl_single to gb:national will: o potentially obscure any underlying data errors (imagine something tagged maxspeed=70 mph, maxspeed:type=GB:nsl_single) o make things more difficult for data consumers (if only by changing the data from something that they might be expecting) o confuse new mappers who see data that they've entered being changed because it's wrong, when in reality there really isn't a concensus on this. I fully accept that national speed limit tagging in the UK is a mess (at the time of writing 4 of the top 6 values for http://taginfo.openstreetmap.org.uk/keys/maxspeed:type#values could mean the same thing) but any consolidation must proceed following discussion. With regard to the other point: For avoidance of doubt, all my edits have been fully manual. I don't believe that anyone has suggested otherwise, although I have certainly suggested that you may not have visited all of the places that you have been changing the speed limit for. There is clearly a sliding scale between I've surveyed an area, and everything that I've edited is based on the results of that survey, aided by e.g. Bing, OSSV, and other named sources and I've changed a bunch of tags worldwide based on who knows what information without even looking where I've changed them. The wiki's mechanical edit policy http://wiki.openstreetmap.org/wiki/Mechanical_Edit_Policy (as currently written) suggests that changes of this type may be covered (search-and-replace operations using an editor... unless your changes are backed up by knowledge or survey) - I guess that it depends on what you mean by knowledge **. Clearly no-one's going to object to some tag-changing edits (designation=public_fooptath to designation=public_footpath for example) but in this case there's enough doubt - other mappers have said I think the changes should reverted and This tag is vital in the replies to my original mail. Based on that, where you've changed e.g. GB:nsl_single to gb:national would it be possible for you to revert your changes? There's clearly a discussion to be had going forward about which one of GB:blah, UK:blah, gb:blah and uk:blah we need to keep, but based on the replies so far there doesn't appear to be a concensus to support merging of everything into gb:national. Cheers, Andy ** In which case quite possibly mea culpa for the changesets that I refer to here https://lists.openstreetmap.org/pipermail/talk-gb/2013-September/015227.html - it's not black and white. ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] National speed limit changes
IIRC a lot of those tags were added by Chriscf, without any local surveying, and since the value was derived from the speed limit, there's little added value in having separate maxspeed:type values. It's just clutter. What matters to the data user is the maxspeed tag. The maxspeed:type tag is probably only of use to mappers. And not much use to them either. On Tue, Sep 24, 2013 at 2:26 PM, SomeoneElse li...@mail.atownsend.org.ukwrote: Hi Peter, Thanks for replying here. Peter Miller wrote: 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. I understand the potential problem (does a national speed limit dual carriageway slip road count as a dual carriageway or not?) but am concerned that changing e.g. GB:nsl_single to gb:national will: o potentially obscure any underlying data errors (imagine something tagged maxspeed=70 mph, maxspeed:type=GB:nsl_single) o make things more difficult for data consumers (if only by changing the data from something that they might be expecting) o confuse new mappers who see data that they've entered being changed because it's wrong, when in reality there really isn't a concensus on this. I fully accept that national speed limit tagging in the UK is a mess (at the time of writing 4 of the top 6 values for http://taginfo.openstreetmap.org.uk/keys/maxspeed:type#values could mean the same thing) but any consolidation must proceed following discussion. With regard to the other point: For avoidance of doubt, all my edits have been fully manual. I don't believe that anyone has suggested otherwise, although I have certainly suggested that you may not have visited all of the places that you have been changing the speed limit for. There is clearly a sliding scale between I've surveyed an area, and everything that I've edited is based on the results of that survey, aided by e.g. Bing, OSSV, and other named sources and I've changed a bunch of tags worldwide based on who knows what information without even looking where I've changed them. The wiki's mechanical edit policyhttp://wiki.openstreetmap.org/wiki/Mechanical_Edit_Policy (as currently written) suggests that changes of this type may be covered (search-and-replace operations using an editor... unless your changes are backed up by knowledge or survey) - I guess that it depends on what you mean by knowledge **. Clearly no-one's going to object to some tag-changing edits (designation=public_fooptath to designation=public_footpath for example) but in this case there's enough doubt - other mappers have said I think the changes should reverted and This tag is vital in the replies to my original mail. Based on that, where you've changed e.g. GB:nsl_single to gb:national would it be possible for you to revert your changes? There's clearly a discussion to be had going forward about which one of GB:blah, UK:blah, gb:blah and uk:blah we need to keep, but based on the replies so far there doesn't appear to be a concensus to support merging of everything into gb:national. Cheers, Andy ** In which case quite possibly mea culpa for the changesets that I refer to herehttps://lists.openstreetmap.org/pipermail/talk-gb/2013-September/015227.html- it's not black and white. ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] National speed limit changes
On Tue, 24 Sep 2013, Richard Mann wrote: 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. I was once on a speed awareness course. Many of the attendees were unaware of what the limits were on the different kinds of road. So the question was raised as to why a black diagonal line is used and not a value like 50 or 60 or 70 which make life a lot easier. The reason is that the maximum speed is dependent on the kind of vehicle you are driving. It's defined in Rule 125 of the Highway Code which is at: https://www.gov.uk/general-rules-all-drivers-riders-103-to-158/control-of-the-vehicle-117-to-126 So I wonder whether it is appropriate to include maxspeed=70 mph in OSM as it could be misunderstood. It is only appropriate for some road users. This was certainly the argument being proposed for not having 70 on road signs. Of course, another reason for not using numerical values on road signs is that if the UK were ever to change the value of the national speed limits then it would mean a lot of signs to change! I guess this does not apply to OSM as global editing is a little easier. Although I lurk on this list, I'm not an OSM contributor. -- Barry Cornelius http://www.northeastraces.com/ http://www.thehs2.com/ http://www.rowmaps.com/ http://www.oxonpaths.com/ http://www.barrycornelius.com/ ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] National speed limit changes
Richard Mann wrote: IIRC a lot of those tags were added by Chriscf, without any local surveying I think that you're thinking about these: http://www.openstreetmap.org/browse/way/81529513/history (a slightly different case) Cheers, Andy ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] National speed limit changes
Barry, Are you saying that a road marked with a numeric sign of '60 mph' defines a different legal maximum speed for some vehicle types from a single carriageway road marked with a white sign and a black diagonal? For example that a bus/coach/car+trailer/HGV less that 7.5 tonnes are only be able to operate at 50 mph on a national limit single carriageway road (for examples one tagged marked maxspeed=60 mph,maxspeed:type=gb:national), but can operate at 60mph on a dual carriageway road signed numerically (ie maxspeed=60 mph;maxspeed:type=sign)? Peter On 24 September 2013 16:04, Barry Cornelius barrycorneliu...@gmail.comwrote: On Tue, 24 Sep 2013, Richard Mann wrote: 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. I was once on a speed awareness course. Many of the attendees were unaware of what the limits were on the different kinds of road. So the question was raised as to why a black diagonal line is used and not a value like 50 or 60 or 70 which make life a lot easier. The reason is that the maximum speed is dependent on the kind of vehicle you are driving. It's defined in Rule 125 of the Highway Code which is at: https://www.gov.uk/general-**rules-all-drivers-riders-103-** to-158/control-of-the-vehicle-**117-to-126https://www.gov.uk/general-rules-all-drivers-riders-103-to-158/control-of-the-vehicle-117-to-126 So I wonder whether it is appropriate to include maxspeed=70 mph in OSM as it could be misunderstood. It is only appropriate for some road users. This was certainly the argument being proposed for not having 70 on road signs. Of course, another reason for not using numerical values on road signs is that if the UK were ever to change the value of the national speed limits then it would mean a lot of signs to change! I guess this does not apply to OSM as global editing is a little easier. Although I lurk on this list, I'm not an OSM contributor. -- Barry Cornelius http://www.northeastraces.com/ http://www.thehs2.com/ http://www.rowmaps.com/ http://www.oxonpaths.com/ http://www.barrycornelius.com/ __**_ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.**org/listinfo/talk-gbhttps://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. ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] National speed limit changes
On Tue, 24 Sep 2013, Peter Miller wrote: Are you saying that a road marked with a numeric sign of '60 mph' defines a different legal maximum speed for some vehicle types from a single carriageway road marked with a white sign and a black diagonal? For example that a bus/coach/car+trailer/HGV less that 7.5 tonnes are only be able to operate at 50 mph on a national limit single carriageway road (for examples one tagged marked maxspeed=60 mph,maxspeed:type=gb:national), but can operate at 60mph on a dual carriageway road signed numerically (ie maxspeed=60 mph;maxspeed:type=sign)? I'm no expert in this area. It may help to look at: http://en.wikipedia.org/wiki/Road_speed_limits_in_the_United_Kingdom#Fixed_speed_limits -- Barry Cornelius http://www.northeastraces.com/ http://www.thehs2.com/ http://www.rowmaps.com/ http://www.oxonpaths.com/ http://www.barrycornelius.com/ ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] National speed limit changes
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
Re: [Talk-GB] National speed limit changes
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. ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] National speed limit changes
On 21 September 2013 00:36, SomeoneElse li...@mail.atownsend.org.uk wrote: I've noticed that locally a number of GB:nsl_single, GB:nsl_dual, and GB:motorway maxspeed:type values have been consolidated into gb:national, so that that gone from nowhere to being the second most-used value: I don't recall there being any consensus on using gb:national in place of the more detailed variants, and I certainly don't think there has been any discussion of or agreement for a mass mechanical edit to change existing values. So if that's what's happened (I haven't looked) I think the changes should reverted pending the outcome of that discussion. From a data point of view, I'd very much prefer to see the more specific values (e.g. nsl_single, nsl_dual, and motorway) used. The type of speed limit is important if you're a non-car where different defaults can apply. While you'll usually be able to tell what sort of speed limit it is from the highway=* and maxspeed=* values, that's additional work on the part of data consumers, and I think it would be better for us to store the redundant information to help them out. Doing so also provides an additional consistency check that will help us detect possible mistakes in our mapping, and will make it easier for us to accurately apply bulk changes to speed limits should the national limits every be changed. Robert. -- Robert Whittaker ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] National speed limit changes
On Sat, 21 Sep 2013 00:36:00 +0100 SomeoneElse li...@mail.atownsend.org.uk wrote: I've noticed that locally a number of GB:nsl_single, GB:nsl_dual, and GB:motorway maxspeed:type values have been consolidated into gb:national, so that that gone from nowhere to being the second most-used value: From a quick skim through the data near me it appears that changes are limited to ways that used to have non-numeric maxspeed values, e.g: maxspeed=GB:nsl_single = maxspeed=60 mph,maxspeed:type=gb:national Has anyone unearthed any that are actually changing an existing maxspeed:type tag? Is this how we're mapping national speed limits now? I've been using the maxspeed=60 mph,maxspeed:type=GB:nsl_single form when mapping and I thought that I was following the herd. Other than simple Garmin maps I'm not a consumer of the data, so am happy with whatever people decide. Actually, I was happy using maxspeed=national until some people (writing routers I think) complained that they couldn't figure out whether national meant 60mph or 70mph and what other restrictions might apply, and insisted on a numeric value in maxspeed, but I was happy to go along with that as long as the fact that it's a national limit rather than a numeric one wasn't lost. I'd agree that maxspeed=national is insufficient as it is impossible to tell what speed you can do in a built up area. 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. I guess if I had the luxury of redesigning the way we tag speed limits it would look something like this: maxspeed=x mph - where x is the posted speed limit or 30/60/70 mph for national speed limit roads. maxspeed:type=GB:(zone|limit|national) - The type of limit in force. carriageway=(single|dual) - The type of road. Apologies if this has already been discussed at length somewhere else, but if so I never got the memo :) Not to my knowledge. -- Regards, Andy Street type of limit in force. carriage ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
[Talk-GB] National speed limit changes
I've noticed that locally a number of GB:nsl_single, GB:nsl_dual, and GB:motorway maxspeed:type values have been consolidated into gb:national, so that that gone from nowhere to being the second most-used value: http://taginfo.openstreetmap.org/keys/maxspeed:type#values An example is: http://www.openstreetmap.org/browse/way/4076295/history Is this how we're mapping national speed limits now? Other than simple Garmin maps I'm not a consumer of the data, so am happy with whatever people decide. Actually, I was happy using maxspeed=national until some people (writing routers I think) complained that they couldn't figure out whether national meant 60mph or 70mph and what other restrictions might apply, and insisted on a numeric value in maxspeed, but I was happy to go along with that as long as the fact that it's a national limit rather than a numeric one wasn't lost. Apologies if this has already been discussed at length somewhere else, but if so I never got the memo :) Cheers, Andy ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
