Re: [Tagging] Carriageway divider
2012/8/26 Martin Koppenhoefer dieterdre...@gmail.com [...] The divider tag has been proposed, but I think it has been demonstrated not to work, as routing decision are made on the node and not on the line. I can't remember that there was a demonstration that this approach doesn't work. Routing engines usually get data that is postprocessed, so the important thing is that the correct information is contained in the data and can be derived. My guess is that nobody has seriously tried to evaluate the divider tag for routing so far. cheers, Martin Indeed the assertion that the router decide on the node (it has been addressed more than once...) let me thought on the real usefulness of the divider tag, at least to help the problem I identified. Anyhow I think that Martin is right: the data have to be processed, also to load the relations for the turn restriction that involve from-via-to nodes and highways. To avoid a turn crossing the continuos line, the divider attribute should have to be checked on - the current highway - the following highway on the driving direction If so a left turn should have to avoided. Simple algorithm, but it looks like out od normal routing schemes, and I don't know if a router could do that (or it could be worth to do that). Ciao Fab, ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 25 August 2012 01:25, Martin Koppenhoefer dieterdre...@gmail.com wrote: 2012/8/20 Markus Lindholm markus.lindh...@gmail.com: I've been mostly mapping in large cities, hardly anything in the countryside. So I can only say that I've found it purposeful in the city to map with two highways when legally separated. purposeful in this case translates to mapping for the router *1 in OSM-speak. We're not supposed to map for the renderer nor the router. Exactly for whom are we to map? There is a convention in OSM that two highways represent two carriageways, so when a single carriageway with a legal divider is mapped like this, it is simply wrong according to our conventions. Sounds like you're the official spokesperson for OSM, are you? The convention you're referring to simply states (physically) Divided highways should be drawn as separate ways. It doesn't say anything about legally divided highways, that is left out. Currently mappers treat legally divided highways in different ways. I'm definitely not the only one to map them as two ways. Also, no one has offered any other solution to the routing issue. The divider tag has been proposed, but I think it has been demonstrated not to work, as routing decision are made on the node and not on the line. /Markus ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 26/08/2012 08:42, Markus Lindholm wrote: Also, no one has offered any other solution to the routing issue. The divider tag has been proposed, but I think it has been demonstrated not to work, as routing decision are made on the node and not on the line. Where has it been demonstrated not to work? What do you mean by routing decision are made on the node and not on the line? Yes, the divider tag is probably not supported by any current routing software. But it would not be too hard to modify the software to allow for it. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On Sun, Aug 26, 2012 at 2:00 PM, Craig Wallace craig...@fastmail.fm wrote: On 26/08/2012 08:42, Markus Lindholm wrote: Also, no one has offered any other solution to the routing issue. The divider tag has been proposed, but I think it has been demonstrated not to work, as routing decision are made on the node and not on the line. Where has it been demonstrated not to work? What do you mean by routing decision are made on the node and not on the line? Yes, the divider tag is probably not supported by any current routing software. But it would not be too hard to modify the software to allow for it. This is an area which has two ways instead of one: http://osm.org/go/0bCzT1kfr-- Here is an route example: http://map.project-osrm.org/1cL Without two ways you would be routed directly to the end point, but with two ways you will be routed with the needed detour. It's especially interesting if you go by bike but then it's more of a psychological divider than a physical (which is another story). I don't like mapping like this, but I'm pragmatic and it does solve a real problem, so I decided no to fight Markus on this. So what is the recommendation for mapping this. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On Sun, 2012-08-26 at 20:30 +0200, Erik Johansson wrote: On Sun, Aug 26, 2012 at 2:00 PM, Craig Wallace craig...@fastmail.fm wrote: On 26/08/2012 08:42, Markus Lindholm wrote: Also, no one has offered any other solution to the routing issue. The divider tag has been proposed, but I think it has been demonstrated not to work, as routing decision are made on the node and not on the line. Where has it been demonstrated not to work? What do you mean by routing decision are made on the node and not on the line? Yes, the divider tag is probably not supported by any current routing software. But it would not be too hard to modify the software to allow for it. This is an area which has two ways instead of one: http://osm.org/go/0bCzT1kfr-- Here is an route example: http://map.project-osrm.org/1cL Without two ways you would be routed directly to the end point, but with two ways you will be routed with the needed detour. It's especially interesting if you go by bike but then it's more of a psychological divider than a physical (which is another story). I don't like mapping like this, but I'm pragmatic and it does solve a real problem, so I decided no to fight Markus on this. So what is the recommendation for mapping this. Its a difficult question. The pragmatic approach I would take is the driver should follow the rules and let the satnav catch up. I must admit I have cheated here, and looked at streetview. The U-turn that the router has come up with looks very wrong to me, the road just isn't wide enough to complete the turn from the left lane. To do a U-turn from the right lane, across straight ahead traffic is dangerous. In this case the false dual carriageway seems wrong and gives a wrong impression of what is on the ground. I think the correct and safe answer is this http://map.project-osrm.org/1cX Outside of a built up area, using this method will give the false impression of the existence of dual carriageway and anyone using OSM as a map will expect a fast road and will find a slow one where overtaking is impossible. Phil ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
2012/8/26 Markus Lindholm markus.lindh...@gmail.com: On 25 August 2012 01:25, Martin Koppenhoefer dieterdre...@gmail.com wrote: purposeful in this case translates to mapping for the router *1 in OSM-speak. We're not supposed to map for the renderer nor the router. Exactly for whom are we to map? I guess this is a misconception. With mapping for the router I didn't mean that the data should not be used also for routing. Rather this is read to mean: map something in a way that it does represent something else but in a certain application under certain conditions (e.g. router that does not do routing for emergency vehicles or pedestrians) it still works as if was mapped correctly. There is a convention in OSM that two highways represent two carriageways, so when a single carriageway with a legal divider is mapped like this, it is simply wrong according to our conventions. Sounds like you're the official spokesperson for OSM, are you? No, I am not. I am simply telling you what I remember from former discussions about this topic. This is not the first time someone thinks that it doesn't matter to distinguish between physical (impossible) and legal (forbidden but possible) separation. The convention you're referring to simply states (physically) Divided highways should be drawn as separate ways. It doesn't say anything about legally divided highways, yes, it's how we do documentation. We do (almost) never state what something is not to mean or when it is not to be used, instead we say when it _is_ to be used. Otherwise the wiki gets really hard to read, because there is usually far more things to which a certain tag does not apply. I'm definitely not the only one to map them as two ways. yes, hence the public comment, otherwise I might have written in private to you Also, no one has offered any other solution to the routing issue. there is a proposal (divider tag) and there are turn restrictions. If you separate highways which are not physically divided you create problems for some other use cases like emergency vehicles, pedestrians, bank robbers and so on. The divider tag has been proposed, but I think it has been demonstrated not to work, as routing decision are made on the node and not on the line. I can't remember that there was a demonstration that this approach doesn't work. Routing engines usually get data that is postprocessed, so the important thing is that the correct information is contained in the data and can be derived. My guess is that nobody has seriously tried to evaluate the divider tag for routing so far. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On Tue, Aug 21, 2012 at 1:04 AM, Tobias Knerr o...@tobias-knerr.de wrote: So I think that mapping divider based on pattern type is a better choice than mapping them based on their legal effects. Until now in OSM tagging, all turning restrictions have been described by the restriction, not by the traffic sign itself like arrow_up or arrow_left_crossed-out. Your argument about unambiguous if you know the law locally is true in both translations. Excepted that with solid_line, you ask the applications to know all local laws arround the world. With the value no_u_turn, applications or other contributors around the world understand immediately what it means. Your second argument about multiple tags is correct but the list of line patterns on the ground can be very long as well (double solid line, dotted lines on one side, colours, etc). Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
-Original Message- From: Markus Lindholm [mailto:markus.lindh...@gmail.com] Sent: 20 August 2012 11:51 To: Tag discussion, strategy and related tools Subject: Re: [Tagging] Carriageway divider On 20 August 2012 10:55, Gregory Williams greg...@gregorywilliams.me.uk wrote: -Original Message- From: Markus Lindholm [mailto:markus.lindh...@gmail.com] Sent: 19 August 2012 19:26 To: Tag discussion, strategy and related tools Subject: Re: [Tagging] Carriageway divider On 19 August 2012 18:23, Tobias Knerr o...@tobias-knerr.de wrote: On 19.08.2012 15:09, Markus Lindholm wrote: On 19 August 2012 14:49, Fabrizio Carrai fabrizio.car...@gmail.com wrote: This could be a solution but it is against the reality: this kind of road are indeed a single entity. The legal division, i.e. the solid_line is just an attribute. There's a multitude of cases where a single entity is represented by multiple objects in the database, e.g. when the road changes speed limit it has to be split into two highway objects. The same with bus routes, to accommodate then the road was to be split into many parts. A major difference is that it is comparatively easy to re-assemble a way that has been split (because they have common nodes). It's not so easy with two parallel ways that somehow belong together - the connection could only be established by rather complex heuristics based on proximity among other things. In practice, it would simply result in gaps or overlaps appearing randomly depending how parallel the mapper has actually drawn the ways, and on the width assumed (or tagged) for the ways. For which purpose would the two highways be reassembled? Split highways may be reassembled when you're not interested in the attributes that do change between them. For example when you want to reassemble the portions of the same road with the same class and name together but aren't interested in the fact that the speed limit changes partway down, the lighting changes, the surface changes, or that a small portion of it has a cycle or bus route which crosses it for a few tens of metres. If building a routing graph from the data you'd want to keep the graph as simple as possible by ignoring the tags not relevant to your routing and reassembling the adjacent otherwise identical segments. Yes, I understand why one would reassemble highway segments on a route that only differ on the maxspeed tag or other such minor issue. But why would one want to reassemble two highways going in opposite direction and from which there is no direct legal route to the other? /Markus Most of this still applies to two parallel opposite highways. When building a routing graph you may want to combine the opposing ways together into one way that represents both directions in order to simplify the routing graph. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
-Original Message- From: Gregory Williams [mailto:grego...@geode.demon.co.uk] Sent: 21 August 2012 09:32 To: 'winfi...@gmail.com'; 'Tag discussion, strategy and related tools' Subject: RE: [Tagging] Carriageway divider From: Jo [mailto:winfi...@gmail.com] Sent: 20 August 2012 10:06 To: Tag discussion, strategy and related tools Subject: Re: [Tagging] Carriageway divider For which purpose would the two highways be reassembled? Split highways may be reassembled when you're not interested in the attributes that do change between them. For example when you want to reassemble the portions of the same road with the same class and name together but aren't interested in the fact that the speed limit changes partway down, the lighting changes, the surface changes, or that a small portion of it has a cycle or bus route which crosses it for a few tens of metres. If building a routing graph from the data you'd want to keep the graph as simple as possible by ignoring the tags not relevant to your routing and reassembling the adjacent otherwise identical segments. You mean one can do this in postprocessing, not in the OSM-database. Otherwise I'd have a lot of work (again) to fix the route relations I'm tending to. Polyglot Yes, I do of course mean that this is a postprocessing step and not in the OSM database. Gregory ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
You are allowed to cross a solid line, providing it is safe, to enter ajoining premises or a side road. In cases where this is prohibited there will be a sign and this should be tagged with a turn restrictions. The rules are country-specific. In the UK you are allowed to do this. In Germany, France, Italy (at least in theory) you are not. Volker ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
I live in hope that, one day, we might have documented defaults or implied values per territory. Until that time, we may have to map both the tangible artefact (solid line) and the implications for routing (no u-turns etc.) separately. They are distinct concepts, related by the rules of the territory. Colin On 21/08/2012 09:47, Pieren wrote: On Tue, Aug 21, 2012 at 1:04 AM, Tobias Knerr o...@tobias-knerr.de wrote: So I think that mapping divider based on pattern type is a better choice than mapping them based on their legal effects. Until now in OSM tagging, all turning restrictions have been described by the restriction, not by the traffic sign itself like arrow_up or arrow_left_crossed-out. Your argument about unambiguous if you know the law locally is true in both translations. Excepted that with solid_line, you ask the applications to know all local laws arround the world. With the value no_u_turn, applications or other contributors around the world understand immediately what it means. Your second argument about multiple tags is correct but the list of line patterns on the ground can be very long as well (double solid line, dotted lines on one side, colours, etc). Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
Le 21/08/2012 13:04, Colin Smale a écrit : I live in hope that, one day, we might have documented defaults or implied values per territory. Until that time, we may have to map both the tangible artefact (solid line) and the implications for routing (no u-turns etc.) separately. They are distinct concepts, related by the rules of the territory. This proposal is for you... http://wiki.openstreetmap.org/wiki/Relations/Proposed/Defaults -- FrViPofm ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 2012-08-19 at 14:09:18 +0200, Markus Lindholm wrote: In my opinion it's best to treat legal separation (i.e. solid_line) the same way as physical separation, i.e. create two separate highways, one in each direction. This doesn't correspond to reality: I believe that an emergency vehicle can cross a solid line, while of course they would have problems with a physically separated road. Also, the presence and style of line in the middle of the road gives additional informations that could be useful for the users. * Dashed line: you can overtake wide veicles; probably related to the available speed and chances to be blocked by something slow. * No line: this road is not wide enough to have two proper lanes: if you meet another car have to slow down, or possibly even stop; a router can use this information to choose another slighty longer, but wider road, even in the absence of a precise width tag. -- Elena ``of Valhalla'' ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
During a similar discussion in july ([1]) about u-turn, another existing tag was provided: http://wiki.openstreetmap.org/wiki/Key:overtaking It's about overtaking but the description could be easily enhanced with u-turn restriction as well. Pieren [1] http://gis.19327.n5.nabble.com/Tagging-u-turn-restriction-with-continuous-painted-line-tt5714828.html ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
For which purpose would the two highways be reassembled? Split highways may be reassembled when you're not interested in the attributes that do change between them. For example when you want to reassemble the portions of the same road with the same class and name together but aren't interested in the fact that the speed limit changes partway down, the lighting changes, the surface changes, or that a small portion of it has a cycle or bus route which crosses it for a few tens of metres. If building a routing graph from the data you'd want to keep the graph as simple as possible by ignoring the tags not relevant to your routing and reassembling the adjacent otherwise identical segments. You mean one can do this in postprocessing, not in the OSM-database. Otherwise I'd have a lot of work (again) to fix the route relations I'm tending to. Polyglot ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 20 August 2012 10:55, Gregory Williams greg...@gregorywilliams.me.uk wrote: -Original Message- From: Markus Lindholm [mailto:markus.lindh...@gmail.com] Sent: 19 August 2012 19:26 To: Tag discussion, strategy and related tools Subject: Re: [Tagging] Carriageway divider On 19 August 2012 18:23, Tobias Knerr o...@tobias-knerr.de wrote: On 19.08.2012 15:09, Markus Lindholm wrote: On 19 August 2012 14:49, Fabrizio Carrai fabrizio.car...@gmail.com wrote: This could be a solution but it is against the reality: this kind of road are indeed a single entity. The legal division, i.e. the solid_line is just an attribute. There's a multitude of cases where a single entity is represented by multiple objects in the database, e.g. when the road changes speed limit it has to be split into two highway objects. The same with bus routes, to accommodate then the road was to be split into many parts. A major difference is that it is comparatively easy to re-assemble a way that has been split (because they have common nodes). It's not so easy with two parallel ways that somehow belong together - the connection could only be established by rather complex heuristics based on proximity among other things. In practice, it would simply result in gaps or overlaps appearing randomly depending how parallel the mapper has actually drawn the ways, and on the width assumed (or tagged) for the ways. For which purpose would the two highways be reassembled? Split highways may be reassembled when you're not interested in the attributes that do change between them. For example when you want to reassemble the portions of the same road with the same class and name together but aren't interested in the fact that the speed limit changes partway down, the lighting changes, the surface changes, or that a small portion of it has a cycle or bus route which crosses it for a few tens of metres. If building a routing graph from the data you'd want to keep the graph as simple as possible by ignoring the tags not relevant to your routing and reassembling the adjacent otherwise identical segments. Yes, I understand why one would reassemble highway segments on a route that only differ on the maxspeed tag or other such minor issue. But why would one want to reassemble two highways going in opposite direction and from which there is no direct legal route to the other? /Markus ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 20 August 2012 09:39, Elena ``of Valhalla'' elena.valha...@gmail.com wrote: On 2012-08-19 at 14:09:18 +0200, Markus Lindholm wrote: In my opinion it's best to treat legal separation (i.e. solid_line) the same way as physical separation, i.e. create two separate highways, one in each direction. This doesn't correspond to reality: I believe that an emergency vehicle can cross a solid line, while of course they would have problems with a physically separated road. I consider legal restrictions to be part of reality. Also consider that a physical separation might be nothing more than a 20cm high curb that could be as easy to cross for an emergency vehicle as a painted line. /Markus ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 20 August 2012 12:57, Markus Lindholm markus.lindh...@gmail.com wrote: On 20 August 2012 09:39, Elena ``of Valhalla'' elena.valha...@gmail.com wrote: On 2012-08-19 at 14:09:18 +0200, Markus Lindholm wrote: In my opinion it's best to treat legal separation (i.e. solid_line) the same way as physical separation, i.e. create two separate highways, one in each direction. This doesn't correspond to reality: I believe that an emergency vehicle can cross a solid line, while of course they would have problems with a physically separated road. I consider legal restrictions to be part of reality. Also consider that a physical separation might be nothing more than a 20cm high curb that could be as easy to cross for an emergency vehicle as a painted line. One other aspect: it would not be possible to create correct routes from an address that's in a middle of a block where the the street has lanes in both direction but that are legally separated. Now if the shortest route would be to turn left (in a country with right hand traffic) but the legal route would require to start the trip by going right, there's no way to express that without having to separate highways, one in each direction. /Markus ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
Isn't that what turn restrictions are for? Colin On 20/08/2012 13:10, Markus Lindholm wrote: On 20 August 2012 12:57, Markus Lindholm markus.lindh...@gmail.com wrote: On 20 August 2012 09:39, Elena ``of Valhalla'' elena.valha...@gmail.com wrote: On 2012-08-19 at 14:09:18 +0200, Markus Lindholm wrote: In my opinion it's best to treat legal separation (i.e. solid_line) the same way as physical separation, i.e. create two separate highways, one in each direction. This doesn't correspond to reality: I believe that an emergency vehicle can cross a solid line, while of course they would have problems with a physically separated road. I consider legal restrictions to be part of reality. Also consider that a physical separation might be nothing more than a 20cm high curb that could be as easy to cross for an emergency vehicle as a painted line. One other aspect: it would not be possible to create correct routes from an address that's in a middle of a block where the the street has lanes in both direction but that are legally separated. Now if the shortest route would be to turn left (in a country with right hand traffic) but the legal route would require to start the trip by going right, there's no way to express that without having to separate highways, one in each direction. /Markus ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 2012-08-20 at 12:57:42 +0200, Markus Lindholm wrote: I consider legal restrictions to be part of reality. Also consider that a physical separation might be nothing more than a 20cm high curb that could be as easy to cross for an emergency vehicle as a painted line. you can't pass a 20cm high curb with sides at a right angle at high speed just like you would pass a painted line; *if* you are able to do it [1]_ you have to slow down and approach it with care. Of course if your roads are separated by a 20 cm high bump with a rounded profile, just like a slighty nasty speed bump, it is a different matter, but that's definitely not the usual road separation around here. .. [1] my car isn't, and most of the auto mediche (a regular car with EMTs on board, which follows the same roules for e.g. ambulances) I've seen aren't. -- Elena ``of Valhalla'' ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 20 August 2012 13:25, Colin Smale colin.sm...@xs4all.nl wrote: Isn't that what turn restrictions are for? No. Turn restrictions restrict from which highway object to which highway object one can traverse, they can't tell whether you're allowed to make a left or right turn at the start of your route. /Markus Colin On 20/08/2012 13:10, Markus Lindholm wrote: On 20 August 2012 12:57, Markus Lindholm markus.lindh...@gmail.com wrote: On 20 August 2012 09:39, Elena ``of Valhalla'' elena.valha...@gmail.com wrote: On 2012-08-19 at 14:09:18 +0200, Markus Lindholm wrote: In my opinion it's best to treat legal separation (i.e. solid_line) the same way as physical separation, i.e. create two separate highways, one in each direction. This doesn't correspond to reality: I believe that an emergency vehicle can cross a solid line, while of course they would have problems with a physically separated road. I consider legal restrictions to be part of reality. Also consider that a physical separation might be nothing more than a 20cm high curb that could be as easy to cross for an emergency vehicle as a painted line. One other aspect: it would not be possible to create correct routes from an address that's in a middle of a block where the the street has lanes in both direction but that are legally separated. Now if the shortest route would be to turn left (in a country with right hand traffic) but the legal route would require to start the trip by going right, there's no way to express that without having to separate highways, one in each direction. /Markus ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On Mon, 2012-08-20 at 13:39 +0200, Markus Lindholm wrote: On 20 August 2012 13:25, Colin Smale colin.sm...@xs4all.nl wrote: Isn't that what turn restrictions are for? No. Turn restrictions restrict from which highway object to which highway object one can traverse, they can't tell whether you're allowed to make a left or right turn at the start of your route. You are allowed to cross a solid line, providing it is safe, to enter ajoining premises or a side road. In cases where this is prohibited there will be a sign and this should be tagged with a turn restrictions. Phil ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On Mon, 2012-08-20 at 12:57 +0200, Markus Lindholm wrote: On 20 August 2012 09:39, Elena ``of Valhalla'' elena.valha...@gmail.com wrote: On 2012-08-19 at 14:09:18 +0200, Markus Lindholm wrote: In my opinion it's best to treat legal separation (i.e. solid_line) the same way as physical separation, i.e. create two separate highways, one in each direction. This doesn't correspond to reality: I believe that an emergency vehicle can cross a solid line, while of course they would have problems with a physically separated road. I consider legal restrictions to be part of reality. Also consider that a physical separation might be nothing more than a 20cm high curb that could be as easy to cross for an emergency vehicle as a painted line. A large vehicle, such as a Fire Appliance, may be able to cross a 20cm high divider. A normal police car, or paramedic car will probably end up at worst grounded and unable to move, or at best with the exhaust ripped off. Phil ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
Hi, On 08/20/2012 12:57 PM, Markus Lindholm wrote: This doesn't correspond to reality: I believe that an emergency vehicle can cross a solid line, while of course they would have problems with a physically separated road. I consider legal restrictions to be part of reality. Yes, but we must make a difference between must not pass and cannot pass. It has already been pointed out that the legal restrictions may not be the same for everyone (emergency services etc.), but even the common motorist or cyclist might choose to ignore legal restrictions - either for banal reason or perhaps because they have an emergency as well - and therefore it is important to distinguish between the physical and the legal side. Bye Frederik -- Frederik Ramm ## eMail frede...@remote.org ## N49°00'09 E008°23'33 ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 2012-08-20 at 14:09:28 +0200, Peter Wendorff wrote: You are allowed to cross a solid line, providing it is safe, to enter ajoining premises or a side road. In cases where this is prohibited there will be a sign and this should be tagged with a turn restrictions. In Germany that's not the case. You're not allowed to cross a solid line. the same applies to Italy. Usually in the case of a side road there will be a vertical sign for convenience, but not for ajoining premises. -- Elena ``of Valhalla'' ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
Yes, when I first read through this thread I was thinking hang on, what's the fuss about? Solid lines don't stop you entering or exiting adjoining premises! But apparently this is not true in many countries of the world. You learn something new every day, etc. So this thread does not apply to the UK, but it's an interesting issue nonetheless :) On Mon, Aug 20, 2012 at 1:39 PM, Elena ``of Valhalla'' elena.valha...@gmail.com wrote: On 2012-08-20 at 14:09:28 +0200, Peter Wendorff wrote: You are allowed to cross a solid line, providing it is safe, to enter ajoining premises or a side road. In cases where this is prohibited there will be a sign and this should be tagged with a turn restrictions. In Germany that's not the case. You're not allowed to cross a solid line. the same applies to Italy. Usually in the case of a side road there will be a vertical sign for convenience, but not for ajoining premises. -- Elena ``of Valhalla'' ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
I think that is the reason why we sould stick with explicit turn restrictions. The law on solid lines varies from country to country, and we cannot expect the routers to code, or know the law for every country, mappers on the ground will be aware of the restrictions however. Phil -- Sent from my Nokia N9 On 20/08/2012 13:09 Peter Wendorff wrote: Am 20.08.2012 13:58, schrieb Philip Barnes: On Mon, 2012-08-20 at 13:39 +0200, Markus Lindholm wrote: On 20 August 2012 13:25, Colin Smale colin.sm...@xs4all.nl wrote: Isn't that what turn restrictions are for? No. Turn restrictions restrict from which highway object to which highway object one can traverse, they can't tell whether you're allowed to make a left or right turn at the start of your route. You are allowed to cross a solid line, providing it is safe, to enter ajoining premises or a side road. In cases where this is prohibited there will be a sign and this should be tagged with a turn restrictions. In Germany that's not the case. You're not allowed to cross a solid line. If you're allowed, the line is dotted for the small part where you are allowed (or a second dotted line on the side where you come from is added). As overtaking has to be finished before the dotted part of the line ends, even that's not allowed by a part of the line being dotted to allow a left turn towards an access ramp to a building or sth. like that. regards Peter ___ Tagging mailing list colin.sm...@xs4all.nl http://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
Am 20.08.2012 15:01, schrieb Philip Barnes: I think that is the reason why we sould stick with explicit turn restrictions. The law on solid lines varies from country to country, and we cannot expect the routers to code, or know the law for every country, mappers on the ground will be aware of the restrictions however. Well... We already require that from routers according to implicit speed limits and much more, so it should not be that complicated to require additional country-dependent defaults for something else. Using explicit turn restrictions might be useful for streets and common ways for these solid lines, but that's not enough as soon as a router want's to start from an address. There's no way tagged from the street to the house itself, so even if it would be handy to do, it's not possible t create turn restrictions here. Therefore I would say, explicit divider tagging should be our goal here. regards Peter ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 20 August 2012 14:06, Frederik Ramm frede...@remote.org wrote: Hi, On 08/20/2012 12:57 PM, Markus Lindholm wrote: This doesn't correspond to reality: I believe that an emergency vehicle can cross a solid line, while of course they would have problems with a physically separated road. I consider legal restrictions to be part of reality. Yes, but we must make a difference between must not pass and cannot pass. It has already been pointed out that the legal restrictions may not be the same for everyone (emergency services etc.), but even the common motorist or cyclist might choose to ignore legal restrictions - either for banal reason or perhaps because they have an emergency as well - and therefore it is important to distinguish between the physical and the legal side. As I said earlier physical separation doesn't necessary mean cannot pass, because physical obstacles come in all kind of different shape and form. Where I live there are plenty of cases of physical separation that any ordinary SUV could easily cross. And then there's the kind that would require a tank. I think that it would be a more pressing objective to be able to provide a legal route from A to B than to cater for all the shortcuts that are possible but not legal. Of course the former doesn't exclude the latter and one could conceive of new schemes to indicate where it's possible to drive but not legal. /Markus ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
2012/8/20 Markus Lindholm markus.lindh...@gmail.com Yes, I understand why one would reassemble highway segments on a route that only differ on the maxspeed tag or other such minor issue. But why would one want to reassemble two highways going in opposite direction and from which there is no direct legal route to the other? What about the roads in the countryside? Would you divide roads into lanes if there is a full line, like in the following picture: http://i.imgur.com/p5Oto.png Janko Mihelić ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On Mon, Aug 20, 2012 at 4:21 PM, Markus Lindholm markus.lindh...@gmail.com wrote: The proposal with divider=solid_line has a disadvantage : the meaning of a solid line differs in countries/continents. It should be better tagged with divider=no_u_turn or no_crossing or whatever you like describing the restriction, not the painted line itself. Another issue is the limitation of one divider per OSM way. As I said earlier physical separation doesn't necessary mean cannot pass, And so what ? The standard defining the limit for dividing highways is long established in OSM (since beginning). I think that it would be a more pressing objective to be able to provide a legal route from A to B than to cater for all the shortcuts that are possible but not legal. Of course the former doesn't exclude the latter and one could conceive of new schemes to indicate where it's possible to drive but not legal. Of course. Like drawing all possible ways to cross a wood. Or the points where you can climb a wall or a fence. Endless, no ? Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
Then it is up to the driver to follow the rules, and allow the router to re-plan. Mapping to this level is really a non-starter, mapping every solid line is not going to happen. On rural trunk roads they are just frequent, ass they are used to prevent overtaking on bends, and there are a lot of those. Phil -- Sent from my Nokia N9 On 20/08/2012 15:21 Markus Lindholm wrote: On 20 August 2012 14:06, Frederik Ramm frede...@remote.org wrote: Hi, On 08/20/2012 12:57 PM, Markus Lindholm wrote: This doesn't correspond to reality: I believe that an emergency vehicle can cross a solid line, while of course they would have problems with a physically separated road. I consider legal restrictions to be part of reality. Yes, but we must make a difference between must not pass and cannot pass. It has already been pointed out that the legal restrictions may not be the same for everyone (emergency services etc.), but even the common motorist or cyclist might choose to ignore legal restrictions - either for banal reason or perhaps because they have an emergency as well - and therefore it is important to distinguish between the physical and the legal side. As I said earlier physical separation doesn't necessary mean cannot pass, because physical obstacles come in all kind of different shape and form. Where I live there are plenty of cases of physical separation that any ordinary SUV could easily cross. And then there's the kind that would require a tank. I think that it would be a more pressing objective to be able to provide a legal route from A to B than to cater for all the shortcuts that are possible but not legal. Of course the former doesn't exclude the latter and one could conceive of new schemes to indicate where it's possible to drive but not legal. /Markus ___ Tagging mailing list frede...@remote.org http://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
2012/8/19 Florian Lohoff f...@zz.de: The turn happens on a node and not on a line. +1, that is true, but each of these nodes is also part of at least 2 highways, and this is not too difficult to evaluate so common turn_restrictions could be created automatically (on a local copy) for routing. Ambiguity might arise in cases where some of these ways do not have a continuous divider line. So interpreting this is difficult and in case there is a sidestreet beeing allowed to turn you split up the way in 3 parts around the node of the junction? Thats broken ... this is not broken, that is what is supposed to be mapped, as the white line will be interrupted there and not continuous. It is not very beautiful to make these additional splits (beside the actual crossing, for the divider), but it is what would be needed to get exact divider details. There are streets where this might make sense - but using the solid_line as indication for turning is not. All IMHO. well, the authorities see this differently, they do use these solid lines to indicate you cannot turn ;-) cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 20 August 2012 16:50, Janko Mihelić jan...@gmail.com wrote: 2012/8/20 Markus Lindholm markus.lindh...@gmail.com Yes, I understand why one would reassemble highway segments on a route that only differ on the maxspeed tag or other such minor issue. But why would one want to reassemble two highways going in opposite direction and from which there is no direct legal route to the other? What about the roads in the countryside? Would you divide roads into lanes if there is a full line, like in the following picture: http://i.imgur.com/p5Oto.png I've been mostly mapping in large cities, hardly anything in the countryside. So I can only say that I've found it purposeful in the city to map with two highways when legally separated. It might well be that that convention doesn't suit well in the countryside, I don't know. So then the convention might differ between city and countryside, like conventions differ between different countries. /Markus ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 20.08.2012 12:51, Markus Lindholm wrote: But why would one want to reassemble two highways going in opposite direction and from which there is no direct legal route to the other? The obvious reason would be implementing any rendering style that represents one physical highway as one line, rather than two lines. There are other potential applications than turn-by-turn navigation or abstract routing graph maps for cars... Tobias ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 20.08.2012 16:53, Pieren wrote: The proposal with divider=solid_line has a disadvantage : the meaning of a solid line differs in countries/continents. It should be better tagged with divider=no_u_turn or no_crossing or whatever you like describing the restriction, not the painted line itself. I disagree for two reasons. One is that the actual road marking pattern and the derived traffic rules are *both* interesting for applications, depending on use case. For example, if your application is doing lane visualization, the actual pattern could be used: http://www.pocketgpsworld.com/reviews/garmin-nuvi-765/lane_assist1.jpg So translation will need to happen anyway, the difference is just the direction. And while the translation form marking to meaning is always unambiguous (if you know the laws of the place), the other direction isn't necessarily. The other reason is that lines have multiple meanings (a solid line might have implications for overtaking, u-turns, other turns, etc., and there might be exceptions for emergency vehicles, obstructed lanes and so on). So you might need multiple tags to map the effect of a single line, and mappers might forget or not even know about some of them. The line style, on the other hand, is easy to identify on the ground and tag. So I think that mapping divider based on pattern type is a better choice than mapping them based on their legal effects. Tobias ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
[Tagging] Carriageway divider
After a short discussion on the italian talk, I would move the discussion in this list. After some tests with OSRM, I missed the availability of a tag to mark the continuos (or discontinued) line that divide the lanes in several single carriageway. In my opinion this is an important indication to the routers to avoid illegal turns across a road. A typical useful application case is a road with many side road [2]. Actually the problem is solved with several turn restriction relations, one for each side way. Tagging the main way with divider=solid_line the problem would have been solved in a easier way, also reflecting the real status of the road. Indeed a Divider=solid_line proposal [3] was already presented . I'm would revamp such proposal. What is your opinion ? Is there any router developer here ? Ciao Fabrizio [1] http://map.project-osrm.org/ [2] https://maps.google.it/maps?q=Via+degli+Acquedotti,+Livorno,+LIhl=itll=43.559379,10.339882spn=93.817658,239.941406sll=43.581112,10.339097sspn=0.095626,0.234318oq=via+degli+acquet=vhnear=Via+degli+Acquedottiz=3layer=cpanoid=AJFk0KCBWPVtT0itjdDSVwcbll=43.559379,10.339882cbp=13,-511.08058985009006,,0,19.495970893735887 [3] http://wiki.openstreetmap.org/wiki/Proposed_features/Divider ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 19 August 2012 11:44, Fabrizio Carrai fabrizio.car...@gmail.com wrote: After a short discussion on the italian talk, I would move the discussion in this list. After some tests with OSRM, I missed the availability of a tag to mark the continuos (or discontinued) line that divide the lanes in several single carriageway. In my opinion this is an important indication to the routers to avoid illegal turns across a road. A typical useful application case is a road with many side road [2]. Actually the problem is solved with several turn restriction relations, one for each side way. Tagging the main way with divider=solid_line the problem would have been solved in a easier way, also reflecting the real status of the road. Indeed a Divider=solid_line proposal [3] was already presented . I'm would revamp such proposal. What is your opinion ? Is there any router developer here ? In my opinion it's best to treat legal separation (i.e. solid_line) the same way as physical separation, i.e. create two separate highways, one in each direction. /Markus ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 19.08.2012 14:09, Markus Lindholm wrote: On 19 August 2012 11:44, Fabrizio Carrai fabrizio.car...@gmail.com wrote: Indeed a Divider=solid_line proposal [3] was already presented . I'm would revamp such proposal. What is your opinion ? Is there any router developer here ? In my opinion it's best to treat legal separation (i.e. solid_line) the same way as physical separation, i.e. create two separate highways, one in each direction. This would make it impossible to treat solid lines and physical separation differently in rendering, so imo it is not an acceptable solution. Tobias ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 19 August 2012 14:49, Fabrizio Carrai fabrizio.car...@gmail.com wrote: This could be a solution but it is against the reality: this kind of road are indeed a single entity. The legal division, i.e. the solid_line is just an attribute. There's a multitude of cases where a single entity is represented by multiple objects in the database, e.g. when the road changes speed limit it has to be split into two highway objects. The same with bus routes, to accommodate then the road was to be split into many parts. Indeed, the current mapping rules [1] indicate that separate ways have to be traced when there is a physical division. That guideline says that a physical separation requires two highway objects, it doesn't say that one shouldn't do the same with legal separation. /Markus ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 19 August 2012 15:04, Tobias Knerr o...@tobias-knerr.de wrote: On 19.08.2012 14:09, Markus Lindholm wrote: On 19 August 2012 11:44, Fabrizio Carrai fabrizio.car...@gmail.com wrote: Indeed a Divider=solid_line proposal [3] was already presented . I'm would revamp such proposal. What is your opinion ? Is there any router developer here ? In my opinion it's best to treat legal separation (i.e. solid_line) the same way as physical separation, i.e. create two separate highways, one in each direction. This would make it impossible to treat solid lines and physical separation differently in rendering, so imo it is not an acceptable solution. No it doesn't, if the physical object that separates the lanes is of interest then create such an object and tag it accordingly. /Markus ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On Sun, Aug 19, 2012 at 11:44:21AM +0200, Fabrizio Carrai wrote: After a short discussion on the italian talk, I would move the discussion in this list. After some tests with OSRM, I missed the availability of a tag to mark the continuos (or discontinued) line that divide the lanes in several single carriageway. In my opinion this is an important indication to the routers to avoid illegal turns across a road. A typical useful application case is a road with many side road [2]. Actually the problem is solved with several turn restriction relations, one for each side way. Tagging the main way with divider=solid_line the problem would have been solved in a easier way, also reflecting the real status of the road. Indeed a Divider=solid_line proposal [3] was already presented . I'm would revamp such proposal. What is your opinion ? Is there any router developer here ? Imho the solid_line is broken - The turn happens on a node and not on a line. So interpreting this is difficult and in case there is a sidestreet beeing allowed to turn you split up the way in 3 parts around the node of the junction? Thats broken ... There are streets where this might make sense - but using the solid_line as indication for turning is not. All IMHO. Flo -- Florian Lohoff f...@zz.de signature.asc Description: Digital signature ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On Sun, 2012-08-19 at 15:04 +0200, Tobias Knerr wrote: On 19.08.2012 14:09, Markus Lindholm wrote: On 19 August 2012 11:44, Fabrizio Carrai fabrizio.car...@gmail.com wrote: Indeed a Divider=solid_line proposal [3] was already presented . I'm would revamp such proposal. What is your opinion ? Is there any router developer here ? In my opinion it's best to treat legal separation (i.e. solid_line) the same way as physical separation, i.e. create two separate highways, one in each direction. This would make it impossible to treat solid lines and physical separation differently in rendering, so imo it is not an acceptable solution. +1 It would also not allow for conditions where the solid line only affects traffic in one direction. Also would imply a dual carriageway and therefore imply a higher speed limit where the National Speed Limit tag has been used. Routers would still have the ascendancy to route U-turns around the end of the division. Really not a solution, the only solution is to add the necessary turn restrictions. Phil ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 19.08.2012 15:09, Markus Lindholm wrote: On 19 August 2012 14:49, Fabrizio Carrai fabrizio.car...@gmail.com wrote: This could be a solution but it is against the reality: this kind of road are indeed a single entity. The legal division, i.e. the solid_line is just an attribute. There's a multitude of cases where a single entity is represented by multiple objects in the database, e.g. when the road changes speed limit it has to be split into two highway objects. The same with bus routes, to accommodate then the road was to be split into many parts. A major difference is that it is comparatively easy to re-assemble a way that has been split (because they have common nodes). It's not so easy with two parallel ways that somehow belong together - the connection could only be established by rather complex heuristics based on proximity among other things. In practice, it would simply result in gaps or overlaps appearing randomly depending how parallel the mapper has actually drawn the ways, and on the width assumed (or tagged) for the ways. I clearly prefer the divider attribute, especially because could be combined with Lanes tagging[1] to model the dividers between lanes for the same direction, too, not just the central divider. Tobias [1] http://wiki.openstreetmap.org/wiki/Lanes ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On Sun, 2012-08-19 at 11:44 +0200, Fabrizio Carrai wrote: After a short discussion on the italian talk, I would move the discussion in this list. After some tests with OSRM, I missed the availability of a tag to mark the continuos (or discontinued) line that divide the lanes in several single carriageway. In my opinion this is an important indication to the routers to avoid illegal turns across a road. A typical useful application case is a road with many side road [2]. Actually the problem is solved with several turn restriction relations, one for each side way. Tagging the main way with divider=solid_line the problem would have been solved in a easier way, also reflecting the real status of the road. Indeed a Divider=solid_line proposal [3] was already presented . I'm would revamp such proposal. What is your opinion ? Is there any router developer here ? How would you tag the direction of the solid line? An example here http://goo.gl/maps/9o06r. Traffic approaching the bend is not allowed to cross the line, traffic leaving the bend is. Through the bend there are double white lines, indicating neither direction may cross. I have never seen a turn restriction, enforced by a solid line however. There will always be a turn restriction sign. It is far simpler to just use the turn restriction where needed, there are very few of them. Whereas nearly every corner will need Divider=solid_line:Forward Divider=solid_line:Forward:Reverse Divider=solid_line:Reverse that will rapidly become tedious for mappers. Phil ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 19 August 2012 18:23, Tobias Knerr o...@tobias-knerr.de wrote: On 19.08.2012 15:09, Markus Lindholm wrote: On 19 August 2012 14:49, Fabrizio Carrai fabrizio.car...@gmail.com wrote: This could be a solution but it is against the reality: this kind of road are indeed a single entity. The legal division, i.e. the solid_line is just an attribute. There's a multitude of cases where a single entity is represented by multiple objects in the database, e.g. when the road changes speed limit it has to be split into two highway objects. The same with bus routes, to accommodate then the road was to be split into many parts. A major difference is that it is comparatively easy to re-assemble a way that has been split (because they have common nodes). It's not so easy with two parallel ways that somehow belong together - the connection could only be established by rather complex heuristics based on proximity among other things. In practice, it would simply result in gaps or overlaps appearing randomly depending how parallel the mapper has actually drawn the ways, and on the width assumed (or tagged) for the ways. For which purpose would the two highways be reassembled? /Markus ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Carriageway divider
On 19 August 2012 15:26, Philip Barnes p...@trigpoint.me.uk wrote: On Sun, 2012-08-19 at 15:04 +0200, Tobias Knerr wrote: On 19.08.2012 14:09, Markus Lindholm wrote: On 19 August 2012 11:44, Fabrizio Carrai fabrizio.car...@gmail.com wrote: Indeed a Divider=solid_line proposal [3] was already presented . I'm would revamp such proposal. What is your opinion ? Is there any router developer here ? In my opinion it's best to treat legal separation (i.e. solid_line) the same way as physical separation, i.e. create two separate highways, one in each direction. This would make it impossible to treat solid lines and physical separation differently in rendering, so imo it is not an acceptable solution. +1 It would also not allow for conditions where the solid line only affects traffic in one direction. Of course if the two opposing lanes aren't mutually legally separated then they shouldn't be created as two highways. Also would imply a dual carriageway and therefore imply a higher speed limit where the National Speed Limit tag has been used. That I don't understand at all. You're not proposing a heuristic algorithm that tries to spot dual carriageways and then impose implied speed limits? Routers would still have the ascendancy to route U-turns around the end of the division. At the next crossing U-turns might be allowed or not and a turn restriction relation should be added if not. /Markus ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
