[OSM-talk] New Google Map Maker promotion
Apparently, OSM is lacking a bus: http://google-latlong.blogspot.com/2009/12/mapping-india-on-googles-internet-bus.html ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
If you are going to tag every culvert in the world, you are talking about adding millions of additional entries to the database. This seems rather unnecessary. -- John F. Eldredge -- j...@jfeldredge.com "Reserve your right to think, for even to think wrongly is better than not to think at all." -- Hypatia of Alexandria -Original Message- From: Steve Bennett Date: Wed, 16 Dec 2009 00:15:48 To: Jukka Rahkonen Cc: Subject: Re: [OSM-talk] Ditches On Tue, Dec 15, 2009 at 11:36 PM, Jukka Rahkonen wrote: > Of course I do not place nodes at the road-ditch intersections. But we have > this > kind of intersections where a ditch is goind under a road through a concrete > or > plastic pipe approximately every fine hundred meters on every single road we > have. Do you suggest that splitting the ways, making 2 meter long sections as > a > "brigde=yes, layer=1" really makes sense? How ofter guessing that highway is > above waterway would fail? Honestly, it sounds like some kind of tag for the node would be appropriate. I would support creating a junction and tagging it "culvert=1", for small cases where "bridge=1" is overkill. (Like the image provided). That would remove ambiguity, and clarify exactly what's happening. Steve ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Tue, Dec 15, 2009 at 11:50 AM, Richard Fairhurst wrote: > > Shalabh wrote: > > 1. A group of really useless people with nothing better to discuss or > > 2. A group of really diligent people making the world's map better > > and being assinine about it. > > 3. A group of no doubt lovely people who have temporarily forgotten about > the existence of the tagging list that way > > Agreed. When I first sent this message I debated the tagging list or the talk list. I figured it might be a solved problem, so I should try the talk list first. Now that we see it isn't a solved problem, followups should go to tagging. If any...right now as I've said to someone else privately, I think I'm just going to add this to my newly started "list of problems with mapping roads as a single line". Maybe collecting all such problems in the same place will help in coming up with a general solution. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
Shalabh wrote: > 1. A group of really useless people with nothing better to discuss or > 2. A group of really diligent people making the world's map better > and being assinine about it. 3. A group of no doubt lovely people who have temporarily forgotten about the existence of the tagging list that way > cheers Richard -- View this message in context: http://old.nabble.com/Ditches-tp26788447p26797913.html Sent from the OpenStreetMap - General mailing list archive at Nabble.com. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
2009/12/15 Frederik Ramm > Hi, > > Chris Hill wrote: > > You've had enough of it!!! After nearly fifty emails about how to tag a > > ditch with a bridge over it in a few hours I think everyone in OSM has > > had enough of it. > > Yes, I thought so too. Maybe we could ditch this discussion? > Damn you stole my lame joke. Emilie Laffray ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
Hi, Chris Hill wrote: > You've had enough of it!!! After nearly fifty emails about how to tag a > ditch with a bridge over it in a few hours I think everyone in OSM has > had enough of it. Yes, I thought so too. Maybe we could ditch this discussion? Bye Frederik ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
2009/12/15 Anthony : > On Tue, Dec 15, 2009 at 11:01 AM, Chris Hill wrote: >> >> Steve Bennett wrote: >> > Alight, I've had enough of this. >> You've had enough of it!!! After nearly fifty emails about how to tag a >> ditch with a bridge over it in a few hours I think everyone in OSM has >> had enough of it. I've rarely seen so much crap in such a small space. >> Haven't any of you heard of restraint? >> >> Clueless doesn't begin to describe it ... > > Maybe you just don't understand the details. Yes, in this particular case > it's a bit contrived, but what if we're talking about a major highway? You > don't want to tag bridges where there are no bridges, that's just going to > confuse people when their car tells them to "continue over the bridge". And > you don't want to show a gap between the ditch and the road where one does > not exist, because someone might be tempted to try to walk there, and maybe > they want to find a different route rather than walking over a major > highway. > Don't make much difference unless you are going to give the road a width, Mark the culvert to start where the culvert starts, and also where it ends. If you want to ensure that nobody wants to believe that there might be a gap between the start of the culvert and the side of the road. Then your going to need some way to give the road width. Generally sides of roads are not marked on OSM only the centre. To map the sides your going to need to map the road as an area like we do with rivers, and this is not really supported yet! (or I believe really wanted) Peter. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Tue, Dec 15, 2009 at 9:31 PM, Chris Hill wrote: > Steve Bennett wrote: > > Alight, I've had enough of this. > You've had enough of it!!! After nearly fifty emails about how to tag a > ditch with a bridge over it in a few hours I think everyone in OSM has > had enough of it. I've rarely seen so much crap in such a small space. > Haven't any of you heard of restraint? > > Clueless doesn't begin to describe it ... > > Chris > > ___ > talk mailing list > talk@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk > Depends how you look at it 1. A group of really useless people with nothing better to discuss or 2. A group of really diligent people making the world's map better and being assinine about it. I would take something between 1 and 2. :) Regards, Shalabh ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Tue, Dec 15, 2009 at 11:01 AM, Chris Hill wrote: > Steve Bennett wrote: > > Alight, I've had enough of this. > You've had enough of it!!! After nearly fifty emails about how to tag a > ditch with a bridge over it in a few hours I think everyone in OSM has > had enough of it. I've rarely seen so much crap in such a small space. > Haven't any of you heard of restraint? > > Clueless doesn't begin to describe it ... > Maybe you just don't understand the details. Yes, in this particular case it's a bit contrived, but what if we're talking about a major highway? You don't want to tag bridges where there are no bridges, that's just going to confuse people when their car tells them to "continue over the bridge". And you don't want to show a gap between the ditch and the road where one does not exist, because someone might be tempted to try to walk there, and maybe they want to find a different route rather than walking over a major highway. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Wed, Dec 16, 2009 at 2:53 AM, Anthony wrote: > Well, my only other alternatives are to screw up the geometry (there's no > gap between the edge of the road and the edge of the tunnel) or to map the > road as an area. Not seeing the problem. --):=|==:(--- - Ditch ) ( end of ditch, start of tunnel (where you mark it) = tunnel : actual edge of road | Where the road is marked in OSM. Not sure what you mean by "screw up the geometry". If you mean, "can't translate reality onto the map millimetre by millimetre", welcome to OSM. The map is what counts, it should just be "near enough" to reality, not perfect. Steve ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
Steve Bennett wrote: > Alight, I've had enough of this. You've had enough of it!!! After nearly fifty emails about how to tag a ditch with a bridge over it in a few hours I think everyone in OSM has had enough of it. I've rarely seen so much crap in such a small space. Haven't any of you heard of restraint? Clueless doesn't begin to describe it ... Chris ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Tue, Dec 15, 2009 at 10:22 AM, Steve Bennett wrote: > Oh, I've finally understood..oops. You want to map this as a node, not > a way. Well, my only other alternatives are to screw up the geometry (there's no gap between the edge of the road and the edge of the tunnel) or to map the road as an area. Maybe barrier=culvert is appropriate after all...but it's kind of gross. > Maybe I'll just map the road as an area ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Tue, Dec 15, 2009 at 10:18 AM, Steve Bennett wrote: > On Wed, Dec 16, 2009 at 2:11 AM, Anthony wrote: > > On Tue, Dec 15, 2009 at 10:03 AM, Anthony wrote: > >> > >> barrier=drainpipe (as an "access node"), access=yes? > > > > I guess barrier=culvert would be the more general and international term? > > Um, a culvert isn't a barrier, by definition. Neither is an entrance or a stile. See "access node" at http://wiki.openstreetmap.org/wiki/Key:barrier ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Wed, Dec 16, 2009 at 2:03 AM, Anthony wrote: > which I don't see as a bridge. I could go with tunnel=yes on the "ditch", > but it's really not a ditch at all at the point it passes under the road. Before the road: waterway=drain, barrier=ditch Under the road: waterway=drain, tunnel=yes > Honestly, I don't see how the road situation isn't a case of > barrier=entrance. The ditch stops for a little bit where the road crosses > it. Under the road is not a ditch, but a drainpipe. barrier=entrance + > drainpipe=yes? Depends how important the water is. Using barrier=entrance you're basically saying "there's a ditch on the left, and a ditch on the right, but there's a gap between them that you can drive through". Using "waterway=drain tunnel=yes", you're saying "there was water flowing through an open ditch on the left, then it went into a tunnel under the road, now it's flowing through an open ditch on the right". Your call. > That's mapped as a junction, not a bridge (barrier=wall, bridge=yes?), and > it's pretty much the same thing (only, underground instead of over ground). > > barrier=drainpipe (as an "access node"), access=yes? Oh, I've finally understood..oops. You want to map this as a node, not a way. Maybe barrier=culvert is appropriate after all...but it's kind of gross. Steve ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
[OSM-talk] Osmarender problems
Hello. I tried to render a data set of our region which we recently mapped using Osmarender. The rendering was fine. I could get the svg image. The problem was that, there where no names in the map, including the highways, buildings etc. What could be wrong? Please help out. Thanks! Regards. -- Sajjad Anwar http://sajjad.in ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Wed, Dec 16, 2009 at 2:11 AM, Anthony wrote: > On Tue, Dec 15, 2009 at 10:03 AM, Anthony wrote: >> >> barrier=drainpipe (as an "access node"), access=yes? > > I guess barrier=culvert would be the more general and international term? Um, a culvert isn't a barrier, by definition. Maybe waterway=culvert for the node. Steve ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Tue, Dec 15, 2009 at 10:03 AM, Anthony wrote: > barrier=drainpipe (as an "access node"), access=yes? > I guess barrier=culvert would be the more general and international term? ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Tue, Dec 15, 2009 at 7:01 AM, Martin Koppenhoefer wrote: > No, there's no junction node as the bridge goes over it, so > barrier=entrance is not right here. Thanks everyone, especially Mike Harris and Martin Koppenhoefer. I'm convinced that barrier=entrance is wrong in this case. The two wood bridges I'll have to split (in Merkaartor I guess as that's the only editor I can get to work with the USGS high res imagery). I'm still a little unsure about the roadway. Because of the use of the drainpipes it's more like ( http://www.coquillewatershed.org/Project%20photos/pages/lampa-199-culvert-03.htm), which I don't see as a bridge. I could go with tunnel=yes on the "ditch", but it's really not a ditch at all at the point it passes under the road. Also, because the roadway is linear, splitting the ditch doesn't really get the geometry right, it leaves a gap. Honestly, I don't see how the road situation isn't a case of barrier=entrance. The ditch stops for a little bit where the road crosses it. Under the road is not a ditch, but a drainpipe. barrier=entrance + drainpipe=yes? http://wiki.openstreetmap.org/wiki/Image:Sallyport.jpg That's mapped as a junction, not a bridge (barrier=wall, bridge=yes?), and it's pretty much the same thing (only, underground instead of over ground). barrier=drainpipe (as an "access node"), access=yes? ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
Alight, I've had enough of this. Let's try and resolve the "should layer tags be required" at the right place: http://wiki.openstreetmap.org/wiki/Talk:Key:layer#Is_layer_required_for_bridges.2C_tunnels.2C_and_waterways.3F Steve ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Wed, Dec 16, 2009 at 12:54 AM, John Smith wrote: > 2009/12/15 Steve Bennett : >> Carefully talking out what these "sane defaults" are, documenting, and >> using them is not "the lazy thing to do". > > You are assuming people are going to go to lengths to read such doco > and more to the point understand the implications and as a result > alter their behaviour... some would say that is wishful thinking :) Wait a second. I'm the one arguing for "sane defaults" to make sensible decisions where there is no explicit layer tag. You're the one arguing that people should act in a certain way, always using an explicit tag. Just saying. (What I actually think is editors should include as much information as possible to inform user decisions.) > The problem is documentation is sometimes controdictory, the wiki > isn't very useful for tagging documentation because it doesn't enforce > consistency and other nice things needed to be able to do tag > minimisation. There is 2 ways to handle this, fix the problems with > the current documentation system, or redundently tag things, the > latter is easier to an extent to obtain. You are unlikely to convince me that ignoring the wiki and letting it rot is the right solution to any tagging problem. Steve ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
2009/12/15 Steve Bennett : > My argument stands. There is no need to tag layers *except* in those > situations. And in those situations, layers are absolutely required. > (Well, except that underground car parks are/will be tagged as > underground...and again, a convention should be in place to avoid the > necessity for layers.) You are assuming that is normal, but your assumption may only hold true for you. > But, as I just said, knock yourself out. Add all the layer tags you > like. It does no harm. No, but taking short cuts and minimising can do harm if people assume one thing, and other people assume another, just look at the mess with highway=cycleway, some deem this very bad because it lacks information that they deem to be critical, again, it's human nature to try and opt for the easy way out and the least amount of effort possible most of the time and the end result could be a mismash of guess work based on what you perceive to be normal. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
2009/12/15 Steve Bennett : > Carefully talking out what these "sane defaults" are, documenting, and > using them is not "the lazy thing to do". You are assuming people are going to go to lengths to read such doco and more to the point understand the implications and as a result alter their behaviour... some would say that is wishful thinking :) > Oh yeah, because the world is just *full* of triple decker bridges :) I thought we were talking about water ways and road ways... > So...following a documented convention that waterways are "below" > roads is akin to Y2K? I'm not seeing it. No I was describing human nature of doing the least possible, in the case of y2k it's dropping the first 2 digits of the year, in tagging it leaves you open to guess work, the problem is human nature. > The best I can propose is that *you* keep adding the redundant tags, > and *I* will follow documented convention (assuming it *is* documented > - heh), and tag the minimum required. And hopefully one day someone > will figure out a way of cleaning up this mess. The problem is documentation is sometimes controdictory, the wiki isn't very useful for tagging documentation because it doesn't enforce consistency and other nice things needed to be able to do tag minimisation. There is 2 ways to handle this, fix the problems with the current documentation system, or redundently tag things, the latter is easier to an extent to obtain. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Wed, Dec 16, 2009 at 12:25 AM, John Smith wrote: > 2009/12/15 Steve Bennett : >> Um, the layer tag helps specifically *only* in cases with bridges over >> bridges...which are exceedingly rare. So I would dispute your premise >> that "the layer tag always helps on a bridge". > > And tunnels over tunnels, possibly multi-story underground car parks > too when we get round to tagging such things. My argument stands. There is no need to tag layers *except* in those situations. And in those situations, layers are absolutely required. (Well, except that underground car parks are/will be tagged as underground...and again, a convention should be in place to avoid the necessity for layers.) But, as I just said, knock yourself out. Add all the layer tags you like. It does no harm. Steve ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Wed, Dec 16, 2009 at 12:25 AM, John Smith wrote: > 2009/12/15 Steve Bennett : >>> You could come up with sane defaults, >> That's the right thing to do. > > Right is a preconceived notion, in this case it's the lazy thing to > do, not nessicarily the right thing to do. Carefully talking out what these "sane defaults" are, documenting, and using them is not "the lazy thing to do". > Frequent for which location/place? You are already making assumptions > about what you consider as normal, not what is most common in the > world at large. Oh yeah, because the world is just *full* of triple decker bridges :) (Not really sure what you were thinking there.) > Humans tend to be lazy, the whole y2k bug thing, which was overly > hyped anyway, wasn't due to lack of bits of memory for storing the > full year, not just the last 2 digits, it was just human laziness that > dropped the first 2 digits and this is a similar case, dropping a tag > because it isn't seen as relevent at this exact moment in time. So...following a documented convention that waterways are "below" roads is akin to Y2K? I'm not seeing it. Honestly, these same flamewars are recurring with alarming frequency. I always seem to find myself on the opposite side of the fence from people who (as I interpret it) enjoy tagging every possible detail as thoroughly as possible. They get annoyed when people like me propose working out the minimum number of tags required for a situation, and following that scheme. The best I can propose is that *you* keep adding the redundant tags, and *I* will follow documented convention (assuming it *is* documented - heh), and tag the minimum required. And hopefully one day someone will figure out a way of cleaning up this mess. Steve ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
2009/12/15 Steve Bennett : > Um, the layer tag helps specifically *only* in cases with bridges over > bridges...which are exceedingly rare. So I would dispute your premise > that "the layer tag always helps on a bridge". And tunnels over tunnels, possibly multi-story underground car parks too when we get round to tagging such things. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
2009/12/15 Steve Bennett : > That's the right thing to do. Right is a preconceived notion, in this case it's the lazy thing to do, not nessicarily the right thing to do. > Not if you document them. I agree that you can't leave everything up This is where explicit tagging can save people from poor/badly written/thought up documentation. > to interpretation, but a road and a waterway crossing without a > junction is, by convention (and rather reasonably so), a road crossing > over the water. If nothing else, it's a far more frequent scenario > than continuously pouring across a public road, and there's a tag for > that. Frequent for which location/place? You are already making assumptions about what you consider as normal, not what is most common in the world at large. > This isn't Law&Order. The whole tagging system is a means whereby This has nothing to do with law, but "knowing" what someone else tagged, rather than guessing. > humans can store facts about the world efficiently, in order that they > can be used unambiguously by tools such as renderers. For that to > work, we need good documentation of what the tags mean, and how to > interpret them. Humans tend to be lazy, the whole y2k bug thing, which was overly hyped anyway, wasn't due to lack of bits of memory for storing the full year, not just the last 2 digits, it was just human laziness that dropped the first 2 digits and this is a similar case, dropping a tag because it isn't seen as relevent at this exact moment in time. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Wed, Dec 16, 2009 at 12:10 AM, Ian Dees wrote: > Although nothing is "required" in OSM, the layer tag always helps on a > bridge because you could have multiple bridges passing each other (as in a > highway interchange). In that case, the layer tag specifies at what "layer" > in the 3rd dimension the bridge exists. Um, the layer tag helps specifically *only* in cases with bridges over bridges...which are exceedingly rare. So I would dispute your premise that "the layer tag always helps on a bridge". Steve ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Tue, Dec 15, 2009 at 11:36 PM, Jukka Rahkonen wrote: > Of course I do not place nodes at the road-ditch intersections. But we have > this > kind of intersections where a ditch is goind under a road through a concrete > or > plastic pipe approximately every fine hundred meters on every single road we > have. Do you suggest that splitting the ways, making 2 meter long sections as > a > "brigde=yes, layer=1" really makes sense? How ofter guessing that highway is > above waterway would fail? Honestly, it sounds like some kind of tag for the node would be appropriate. I would support creating a junction and tagging it "culvert=1", for small cases where "bridge=1" is overkill. (Like the image provided). That would remove ambiguity, and clarify exactly what's happening. Steve ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Tue, Dec 15, 2009 at 11:36 PM, John Smith wrote: > Without layer information you'd be guessing if the road goes over the > water or the water goes over the road, or the water and road are at > the same level. > > You could come up with sane defaults, That's the right thing to do. > but that's making assumptions Not if you document them. I agree that you can't leave everything up to interpretation, but a road and a waterway crossing without a junction is, by convention (and rather reasonably so), a road crossing over the water. If nothing else, it's a far more frequent scenario than continuously pouring across a public road, and there's a tag for that. > rather than tagging explicitly so you know beyond a reasonable doubt. This isn't Law&Order. The whole tagging system is a means whereby humans can store facts about the world efficiently, in order that they can be used unambiguously by tools such as renderers. For that to work, we need good documentation of what the tags mean, and how to interpret them. Steve ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Tue, Dec 15, 2009 at 6:52 AM, Richard Mann < richard.mann.westoxf...@googlemail.com> wrote: > bridge=yes is so that people can render nice parapets > > I'd agree that layer tags should not be required for water/highway > crossings. Keepright should keepquiet! > Although nothing is "required" in OSM, the layer tag always helps on a bridge because you could have multiple bridges passing each other (as in a highway interchange). In that case, the layer tag specifies at what "layer" in the 3rd dimension the bridge exists. See for example http://osm.org/go/ZVMvmEVc ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
Kylla .. tosi on ... I wouldn't normally put in a culvert anyway ... it was just an example ... The only trouble with letting the way and the waterway cross with no layers is that some of the validators object ... not sure how important that is ... Mike Harris > -Original Message- > From: Jukka Rahkonen [mailto:jukka.rahko...@mmmtike.fi] > Sent: 15 December 2009 11:20 > To: talk@openstreetmap.org > Subject: Re: [OSM-talk] Ditches > > It feels sometimes ridiculous to add layer tag to ditches and > roads because everybody knows that in majority of cases when > road and ditch are crossing, the road is above. A very > typical example is in picture: > http://www.coquillewatershed.org/Project%20photos/pages/lampa- > 199-culvert-03.htm > > There are millions of culverts like this. Are they really > worth splitting the way and tagging a "bridge"? I do not > bother myself, I just let road and waterway to cross without > any layers. > > -Jukka Rahkonen- > > > > > > ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
2009/12/15 Peter Childs : > If you have a bridge or a tunnel you don't need a layer tag a bridge > infers it "goes over" a tunnel that it "goes over" Let's start with the basics, we're talking about a water way and a road way, what if neither is tagged with layer or tunnel or bridge tags and there is no connecting nodes for the 2 ways, > If there is neither a tunnel, or a bridge and no layer either then it > must be a ford. Only if there is a connecting node, otherwise you are just guessing as what it should be. > If you mark bridge=yes, layer=1 you are repeating your self. which is > where problems start, see database normalisation. That's making the assumption that all redundency is a bad thing, some times it helps reduce guesswork. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
I guess we have to decide whether culverts or fords are the more common (and explicitly tag the less-common). I'd plump for culverts being significantly more common myself, but that might not be true on a whole-world basis. Richard On Tue, Dec 15, 2009 at 12:49 PM, Peter Childs wrote: > 2009/12/15 John Smith : > > 2009/12/15 Steve Bennett : > >> IMHO, tagging "layer=1 bridge=yes" for a road going over water is an > >> example of a hack, and "tagging for the renderer". The information > >> "bridge=1" is more than enough to render with, so "layer=1" can *only* > >> be interpreted as giving a renderer a crutch. > > > > Without layer information you'd be guessing if the road goes over the > > water or the water goes over the road, or the water and road are at > > the same level. > > > > You could come up with sane defaults, but that's making assumptions > > rather than tagging explicitly so you know beyond a reasonable doubt. > > > > If you have a bridge or a tunnel you don't need a layer tag a bridge > infers it "goes over" a tunnel that it "goes over" > > If there is neither a tunnel, or a bridge and no layer either then it > must be a ford. > > If you mark bridge=yes, layer=1 you are repeating your self. which is > where problems start, see database normalisation. > > Peter. > > ___ > talk mailing list > talk@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk > ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
bridge=yes is so that people can render nice parapets I'd agree that layer tags should not be required for water/highway crossings. Keepright should keepquiet! Richard On Tue, Dec 15, 2009 at 12:36 PM, Jukka Rahkonen wrote: > Pieren gmail.com> writes: > > > Always add the layer tag. And don't add a node at the intersection if > > they are not at the same layer. Otherwise how any software can "guess" > > if it's an intersection or not ? By going through thousands different > > combinations of highways/waterways/railways/etc tags ? > > Of course I do not place nodes at the road-ditch intersections. But we have > this > kind of intersections where a ditch is goind under a road through a > concrete or > plastic pipe approximately every fine hundred meters on every single road > we > have. Do you suggest that splitting the ways, making 2 meter long sections > as a > "brigde=yes, layer=1" really makes sense? How ofter guessing that highway > is > above waterway would fail? > > -Jukka- > > > > Pieren > > > > > > > > ___ > talk mailing list > talk@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk > ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
2009/12/15 John Smith : > 2009/12/15 Steve Bennett : >> IMHO, tagging "layer=1 bridge=yes" for a road going over water is an >> example of a hack, and "tagging for the renderer". The information >> "bridge=1" is more than enough to render with, so "layer=1" can *only* >> be interpreted as giving a renderer a crutch. > > Without layer information you'd be guessing if the road goes over the > water or the water goes over the road, or the water and road are at > the same level. > > You could come up with sane defaults, but that's making assumptions > rather than tagging explicitly so you know beyond a reasonable doubt. > If you have a bridge or a tunnel you don't need a layer tag a bridge infers it "goes over" a tunnel that it "goes over" If there is neither a tunnel, or a bridge and no layer either then it must be a ford. If you mark bridge=yes, layer=1 you are repeating your self. which is where problems start, see database normalisation. Peter. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
Pieren gmail.com> writes: > Always add the layer tag. And don't add a node at the intersection if > they are not at the same layer. Otherwise how any software can "guess" > if it's an intersection or not ? By going through thousands different > combinations of highways/waterways/railways/etc tags ? Of course I do not place nodes at the road-ditch intersections. But we have this kind of intersections where a ditch is goind under a road through a concrete or plastic pipe approximately every fine hundred meters on every single road we have. Do you suggest that splitting the ways, making 2 meter long sections as a "brigde=yes, layer=1" really makes sense? How ofter guessing that highway is above waterway would fail? -Jukka- > > Pieren > ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
2009/12/15 Steve Bennett : > IMHO, tagging "layer=1 bridge=yes" for a road going over water is an > example of a hack, and "tagging for the renderer". The information > "bridge=1" is more than enough to render with, so "layer=1" can *only* > be interpreted as giving a renderer a crutch. Without layer information you'd be guessing if the road goes over the water or the water goes over the road, or the water and road are at the same level. You could come up with sane defaults, but that's making assumptions rather than tagging explicitly so you know beyond a reasonable doubt. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Tue, Dec 15, 2009 at 11:16 PM, John Smith wrote: > It's not a hack, it's an easy way to order some elements when > rendering so things look right. A hack would be using the layer tag to > alter the rendering order to make things look better if the rendering > config is wrong. Sorry, you're right, "hack" is not the right word. >No ! That's not ok to rely on any "reasonable" renderers. >This is exactly what we mean when we say "don't tag for the renderer". I think what you mean by "don't tag for the renderer" is almost exactly the opposite of what other people mean by it. You: Follow the rules (in this case, the requirements of dumb renderers that needed a layer tag to figure out that water goes below road)), don't expect smart renderers to figure it out. Certain others: Tag reality, renderers will eventually make sense of the data. IMHO, tagging "layer=1 bridge=yes" for a road going over water is an example of a hack, and "tagging for the renderer". The information "bridge=1" is more than enough to render with, so "layer=1" can *only* be interpreted as giving a renderer a crutch. (OTOH, tagging "layer=2 bridge=yes" for a road going over another elevated road is not "tagging for the renderer". It's encoding information that *any* renderer, no matter how smart, would need.) Steve ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
2009/12/15 Steve Bennett : > Asbolutely nothing. You're wy overthinking this, both of you. > Layers are just a hack to make stuff render. It's not like It's not a hack, it's an easy way to order some elements when rendering so things look right. A hack would be using the layer tag to alter the rendering order to make things look better if the rendering config is wrong. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Tue, Dec 15, 2009 at 12:49 PM, Steve Bennett wrote: > Anyway, I'm pretty sure it's already ok to have drain and road cross > (without junction) at layer=0 - they'll be rendered right by any > reasonable renderer. No ! That's not ok to rely on any "reasonable" renderers. This is exactly what we mean when we say "don't tag for the renderer". Always add the layer tag. And don't add a node at the intersection if they are not at the same layer. Otherwise how any software can "guess" if it's an intersection or not ? By going through thousands different combinations of highways/waterways/railways/etc tags ? Pieren Pieren ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
Steve Bennett gmail.com> writes: > Anyway, I'm pretty sure it's already ok to have drain and road cross > (without junction) at layer=0 - they'll be rendered right by any > reasonable renderer. It should be obvious that water is the bottom > layer, and power lines are the top layer, unless any layer tags say > otherwise. The layers are just there to solve ambiguous cases like two > bridges crossing (completely ambiguous). That's true. It is only Keep right that keeps on nagging but I don't care. -Jukka- ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
2009/12/15 Anthony > On Mon, Dec 14, 2009 at 10:47 PM, Anthony wrote: > >> So I've used barrier=entrance for the node where the way and the ditch >> cross. >> > > More specifically, barrier=entrance and bridge=yes. > No, there's no junction node as the bridge goes over it, so barrier=entrance is not right here. Add bridge=yes and layer=1 or layer=-1 to the ditch (which makes layer=1 for the bridge somehow obsolete). Layer=1 or even Layer=5 could be at ground level (I usually wouldn't use it like that, but you can, and you even have to with more than 5 bridges one over the other where the topmost is on groundlevel), there is nothing bad about this. Cheers, Martin ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] How is there not any creative-type (US) copyright in OSM data?
Richard Fairhurst wrote: > Anthony wrote: > >> Ah, but I don't plan on ever visiting the OSM website when and if >> they switch to the ODbL. >> > > Best. Reason to switch to ODbL. Ever. > > Richard > +1 ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Tue, Dec 15, 2009 at 10:19 PM, Jukka Rahkonen wrote: > It feels sometimes ridiculous to add layer tag to ditches and roads because > everybody knows that in majority of cases when road and ditch are crossing, > the > road is above. A very typical example is in picture: > http://www.coquillewatershed.org/Project%20photos/pages/lampa-199-culvert-03.htm > > There are millions of culverts like this. Are they really worth splitting the > way and tagging a "bridge"? I do not bother myself, I just let road and > waterway to cross without any layers. That doesn't look like a bridge by any stretch of the imagination. Perhaps a tunnel. Perhaps nothing. Anyway, I'm pretty sure it's already ok to have drain and road cross (without junction) at layer=0 - they'll be rendered right by any reasonable renderer. It should be obvious that water is the bottom layer, and power lines are the top layer, unless any layer tags say otherwise. The layers are just there to solve ambiguous cases like two bridges crossing (completely ambiguous). Btw, to mike: >Fair points ... If it really doesn't matter to routers and other mappers and >doesn't interfere with anything else then I am happy to accept that there is >no fully logical solution and that it shouldn't matter to me either! Cool! I was thinking, it may help to think of all these features as being drawn on little postit notes. The desk is covered with postit notes, and sometimes they overlap. "Layer=" tells you which one is on top, when they overlap, but it's meaningless whenever there is no overlap. And notice that a postit note could be the bottom of one pile (layer=-2), but also the top of another pile (layer=+3). So that's why you break the way in the middle to change the layer, without causing any problems - or waterfalls. (And no, the desk is not layer=0. Layer=0 is as arbitrary as any other, it's just the convention for most roads on the ground.) Steve ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
Fair points ... If it really doesn't matter to routers and other mappers and
doesn't interfere with anything else then I am happy to accept that there is
no fully logical solution and that it shouldn't matter to me either!
Mike Harris
> -Original Message-
> From: Steve Bennett [mailto:stevag...@gmail.com]
> Sent: 15 December 2009 11:18
> To: Mike Harris
> Cc: openstreetmap
> Subject: Re: [OSM-talk] Ditches
>
> On Tue, Dec 15, 2009 at 8:07 PM, Mike Harris
> wrote:
> >> Layers are only there to explain the relative heights of
> things when
> >> they meet. No harm will result from marking the ditch as layer -1.
> >
> > See my separate reply - I disagree - what happens when the
> "level=-1"
> > ditch runs downstream into a "level=0" stream / river -
> without a waterfall?
>
> Asbolutely nothing. You're wy overthinking this, both of you.
> Layers are just a hack to make stuff render. It's not like
> "bicycle=no" or something where we're making some statement
> of fact about the real world. Layers are *not* a statement of
> fact. Layer=3 does not, in the absolute, mean anything
> different from Layer=2.
>
> >
> >> Whether or not it needs to be a lower number than that of
> the bridge
> >> is an unresolved question.
> >
> > I disagree - surely the bridge is above the water in the
> ditch and so
> > - by your own defintion ('relative heights') it must have a
> higher level value?
>
> You're trying to apply some sort of intuition or logic to this. Don't.
> It's not some logic puzzle where the layers all have to mean
> something. I've worked in areas where someone, for some
> reason, has tagged all the bike paths in a park as layer=1.
> It didn't matter. I eventually deleted the layer tags because
> they interfered with my own tagging scheme, but it was
> nothing more than personal preference.
>
> >> Not sure I'd even mark it "barrier=ditch" after all that. I'd also
> >> only specify a layer for the bridge, not the ditch/drain.
> >
> > Agree - enough to mark it as a stream or, if that is felt
> to be too 'big'
> > then waterway=ditch.
>
> I doublechecked the wiki, looks like "barrier=ditch, waterway=drain"
> might be the right way to go. Belt and braces, you know.
>
> > Also agree that the bridge, rather than the ditch, should carry the
> > layer tag (see my comment above).
>
> It. Really. Doesn't. Matter. :)
>
> Say you have a stream at layer=3, and somewhere else it
> crosses a big complicated bridge which for some reason
> someone has tagged layer=-2.
> You know what you do? You don't panic. You break the stream,
> you set the new part as layer=-3, and you carry on.
>
> >Doesn't this rather imply that the ditch has the same layer
> value as
> >the level=0 surroundings (as I suggest) rather than
> > level=-1 (as per your 'no harm' suggestion) - and that the
> bridge has
> >a layer value higher than 0, so presumably level=1 (as I suggest)?
>
> Overthinking.
>
> I am curious to know if any routers look at layers when you
> have something like a big routable area (eg,
> highway=pedestrian) with barriers within it, though.
>
> Steve
>
>
>
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Re: [OSM-talk] How is there not any creative-type (US) copyright in OSM data?
Anthony wrote: > Ah, but I don't plan on ever visiting the OSM website when and if > they switch to the ODbL. Best. Reason to switch to ODbL. Ever. Richard -- View this message in context: http://old.nabble.com/How-is-there-not-any-creative-type-%28US%29-copyright-in-OSM-data--tp26665700p26793270.html Sent from the OpenStreetMap - General mailing list archive at Nabble.com. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
It feels sometimes ridiculous to add layer tag to ditches and roads because everybody knows that in majority of cases when road and ditch are crossing, the road is above. A very typical example is in picture: http://www.coquillewatershed.org/Project%20photos/pages/lampa-199-culvert-03.htm There are millions of culverts like this. Are they really worth splitting the way and tagging a "bridge"? I do not bother myself, I just let road and waterway to cross without any layers. -Jukka Rahkonen- ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
On Tue, Dec 15, 2009 at 8:07 PM, Mike Harris wrote:
>> Layers are only there to explain the relative heights of
>> things when they meet. No harm will result from marking the
>> ditch as layer -1.
>
> See my separate reply - I disagree - what happens when the "level=-1" ditch
> runs downstream into a "level=0" stream / river - without a waterfall?
Asbolutely nothing. You're wy overthinking this, both of you.
Layers are just a hack to make stuff render. It's not like
"bicycle=no" or something where we're making some statement of fact
about the real world. Layers are *not* a statement of fact. Layer=3
does not, in the absolute, mean anything different from Layer=2.
>
>> Whether or not it needs to be a lower number than that of the
>> bridge is an unresolved question.
>
> I disagree - surely the bridge is above the water in the ditch and so - by
> your own defintion ('relative heights') it must have a higher level value?
You're trying to apply some sort of intuition or logic to this. Don't.
It's not some logic puzzle where the layers all have to mean
something. I've worked in areas where someone, for some reason, has
tagged all the bike paths in a park as layer=1. It didn't matter. I
eventually deleted the layer tags because they interfered with my own
tagging scheme, but it was nothing more than personal preference.
>> Not sure I'd even mark it "barrier=ditch" after all that. I'd
>> also only specify a layer for the bridge, not the ditch/drain.
>
> Agree - enough to mark it as a stream or, if that is felt to be too 'big'
> then waterway=ditch.
I doublechecked the wiki, looks like "barrier=ditch, waterway=drain"
might be the right way to go. Belt and braces, you know.
> Also agree that the bridge, rather than the ditch, should carry the layer
> tag (see my comment above).
It. Really. Doesn't. Matter. :)
Say you have a stream at layer=3, and somewhere else it crosses a big
complicated bridge which for some reason someone has tagged layer=-2.
You know what you do? You don't panic. You break the stream, you set
the new part as layer=-3, and you carry on.
>Doesn't this rather imply that the ditch has the
> same layer value as the level=0 surroundings (as I suggest) rather than
> level=-1 (as per your 'no harm' suggestion) - and that the bridge has a
> layer value higher than 0, so presumably level=1 (as I suggest)?
Overthinking.
I am curious to know if any routers look at layers when you have
something like a big routable area (eg, highway=pedestrian) with
barriers within it, though.
Steve
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Re: [OSM-talk] Ditches
Keepright fusses if highways with different layers meet at junctions
(because it messes up rendering if the highways are drawn differently). So
where you've got a bridge very close to a junction you have to put in a
short way for the bridge and a very short way linking the bridge to the
junction. Messy, and doesn't always solve the rendering problem, anyway.
Keepright doesn't fuss if waterways meet with different layers.
So the simplest is to consider highways to be layer=0 (and put that
explicitly on the bridge, cos some people take bridge=yes to imply layer=1),
and to make the waterway layer=-1.
Richard
On Tue, Dec 15, 2009 at 9:07 AM, Mike Harris wrote:
>
>
> Mike Harris
>
>
> > -Original Message-
> > From: Steve Bennett [mailto:stevag...@gmail.com]
> > Sent: 15 December 2009 02:43
> > To: Anthony
> > Cc: openstreetmap
> > Subject: Re: [OSM-talk] Ditches
> >
> > On Tue, Dec 15, 2009 at 1:31 PM, Anthony wrote:
> > > In a park is a ditch. There is a very small bridge going
> > over the ditch.
> > > I've tagged the ditch with barrier=ditch. Should the ditch
> > be layer=-1?
> > > Even though the park is layer=0?
> >
> > Layers are only there to explain the relative heights of
> > things when they meet. No harm will result from marking the
> > ditch as layer -1.
>
> See my separate reply - I disagree - what happens when the "level=-1" ditch
> runs downstream into a "level=0" stream / river - without a waterfall?
>
> > Whether or not it needs to be a lower number than that of the
> > bridge is an unresolved question.
>
> I disagree - surely the bridge is above the water in the ditch and so - by
> your own defintion ('relative heights') it must have a higher level value?
>
> > > Should I use barrier=entrance on the node where the ways overlap,
> > > bridge=yes on the bridge (which means splitting the way for a very
> > > short bridge), both, something else?
> >
> > There shouldn't be a junction between the bridge and the
> > ditch, so no need to mark anything barrier=entrance. Just
> > mark the whole bridge bridge=yes.
>
> Agree - but the way has to be split for the bridge=yes section.
>
>
> > > http://wiki.openstreetmap.org/wiki/Image:IMG_6784.JPG
> > > http://wiki.openstreetmap.org/wiki/Image:IMG_6783.JPG
> >
> > The path:
> > highway=footway
> > (possibly bicycle=yes)
> >
> > It then meets a bridge:
> > highway=footway
> > bridge=yes
> > layer=1
> >
> > Then another path:
> > highway=footway
> >
> > Meanwhile, unconnected, but crossing the bridge:
> > waterway=drain
> >
> > Not sure I'd even mark it "barrier=ditch" after all that. I'd
> > also only specify a layer for the bridge, not the ditch/drain.
>
> Agree - enough to mark it as a stream or, if that is felt to be too 'big'
> then waterway=ditch.
>
> Also agree that the bridge, rather than the ditch, should carry the layer
> tag (see my comment above). Doesn't this rather imply that the ditch has
> the
> same layer value as the level=0 surroundings (as I suggest) rather than
> level=-1 (as per your 'no harm' suggestion) - and that the bridge has a
> layer value higher than 0, so presumably level=1 (as I suggest)?
>
> > Steve
> >
> >
> >
>
>
> ___
> talk mailing list
> talk@openstreetmap.org
> http://lists.openstreetmap.org/listinfo/talk
>
___
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Re: [OSM-talk] Ditches
Mike Harris
> -Original Message-
> From: Steve Bennett [mailto:stevag...@gmail.com]
> Sent: 15 December 2009 02:43
> To: Anthony
> Cc: openstreetmap
> Subject: Re: [OSM-talk] Ditches
>
> On Tue, Dec 15, 2009 at 1:31 PM, Anthony wrote:
> > In a park is a ditch. There is a very small bridge going
> over the ditch.
> > I've tagged the ditch with barrier=ditch. Should the ditch
> be layer=-1?
> > Even though the park is layer=0?
>
> Layers are only there to explain the relative heights of
> things when they meet. No harm will result from marking the
> ditch as layer -1.
See my separate reply - I disagree - what happens when the "level=-1" ditch
runs downstream into a "level=0" stream / river - without a waterfall?
> Whether or not it needs to be a lower number than that of the
> bridge is an unresolved question.
I disagree - surely the bridge is above the water in the ditch and so - by
your own defintion ('relative heights') it must have a higher level value?
> > Should I use barrier=entrance on the node where the ways overlap,
> > bridge=yes on the bridge (which means splitting the way for a very
> > short bridge), both, something else?
>
> There shouldn't be a junction between the bridge and the
> ditch, so no need to mark anything barrier=entrance. Just
> mark the whole bridge bridge=yes.
Agree - but the way has to be split for the bridge=yes section.
> > http://wiki.openstreetmap.org/wiki/Image:IMG_6784.JPG
> > http://wiki.openstreetmap.org/wiki/Image:IMG_6783.JPG
>
> The path:
> highway=footway
> (possibly bicycle=yes)
>
> It then meets a bridge:
> highway=footway
> bridge=yes
> layer=1
>
> Then another path:
> highway=footway
>
> Meanwhile, unconnected, but crossing the bridge:
> waterway=drain
>
> Not sure I'd even mark it "barrier=ditch" after all that. I'd
> also only specify a layer for the bridge, not the ditch/drain.
Agree - enough to mark it as a stream or, if that is felt to be too 'big'
then waterway=ditch.
Also agree that the bridge, rather than the ditch, should carry the layer
tag (see my comment above). Doesn't this rather imply that the ditch has the
same layer value as the level=0 surroundings (as I suggest) rather than
level=-1 (as per your 'no harm' suggestion) - and that the bridge has a
layer value higher than 0, so presumably level=1 (as I suggest)?
> Steve
>
>
>
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Re: [OSM-talk] Ditches
Mike Harris > -Original Message- > From: Steve Bennett [mailto:stevag...@gmail.com] > Sent: 15 December 2009 03:38 > To: John Smith > Cc: openstreetmap > Subject: Re: [OSM-talk] Ditches > > On Tue, Dec 15, 2009 at 2:36 PM, John Smith > wrote: > > I tend to mark bridges as layer=1 and anything at ground > level I don't > > set a layer tag, which seems the most logical to me since ditches > > aren't under the ground etc. > > The one benefit of marking waterways layer=-1 (particularly for long > ones) is that it's protection against anyone else forgetting > to set layer=1. That is, someone else might draw a bridge > over it somewhere and not set the layer. Well, if the > waterway itself is -1, that will still behave the same. > > (And there's no downside) I think there are two quite serious downsides: 1. When the waterway (e.g. ditch or stream) eventually links into other, bigger downstream waterways (probably mapped by different people at different times) these are very likely to be tagged (or assumed) as level=0. But there is not usually a reverse waterfall at the junction! (this would be water flowing uphill - as we go upstream the level changes from 0 to -1 !!!). 2. Forgetting to draw a bridge - and give it a layer higher than what is underneath - is naughty (:<) - but surely two wrongs don't make a right? > Steve > > > ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
+1 Mike Harris > -Original Message- > From: John Smith [mailto:deltafoxtrot...@gmail.com] > Sent: 15 December 2009 03:36 > To: Steve Bennett > Cc: openstreetmap > Subject: Re: [OSM-talk] Ditches > > 2009/12/15 Steve Bennett : > > On Tue, Dec 15, 2009 at 1:31 PM, Anthony wrote: > >> In a park is a ditch. There is a very small bridge going > over the ditch. > >> I've tagged the ditch with barrier=ditch. Should the > ditch be layer=-1? > >> Even though the park is layer=0? > > > > Layers are only there to explain the relative heights of > things when > > they meet. No harm will result from marking the ditch as layer -1. > > Whether or not it needs to be a lower number than that of > the bridge > > is an unresolved question. > > I tend to mark bridges as layer=1 and anything at ground > level I don't set a layer tag, which seems the most logical > to me since ditches aren't under the ground etc. > > > ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Ditches
I encounter a similar situation all the time - usually in the context of public footpaths with short foot plank or sleeper bridges over ditches or very small streams in the countryside. My practice - which is open to change if there is a better solution that is widely accepted - is: 1. Split the way over the bridge even though it is short (in fact I sometimes have to go further and also split the way in the middle of the bridge if it is on a boundary and the footpath reference number changes!). 2. Tag the bridge as bridge=yes and layer=1. 3. My rationale for layer=1 (rather than tagging the ditch / stream as layer=-1) is that the ditch / stream (as and when fully mapped) will run at the same level into bigger streams, rivers etc. and these will almost certainly already be tagged (imho correctly) as level=0. Although there may be no physical ascent to get onto the bridge plank (indeed it is often a descent either side as the plank may be a little below the surrounding field level even though it is above the stream) the concept in my mind is that we have gone 'up' relative to something that is at the general level of the countryside to the same extent as, say, a river is at the same general level even though it flows between banks and the surface of the water is actually below the land (most of the time anyway - not last month!). Mike Harris _ From: Anthony [mailto:o...@inbox.org] Sent: 15 December 2009 02:31 To: openstreetmap Subject: [OSM-talk] Ditches In a park is a ditch. There is a very small bridge going over the ditch. I've tagged the ditch with barrier=ditch. Should the ditch be layer=-1? Even though the park is layer=0? Should I use barrier=entrance on the node where the ways overlap, bridge=yes on the bridge (which means splitting the way for a very short bridge), both, something else? (Actually, there are three bridges, one of which carries motor vehicle traffic and two which do not.) http://wiki.openstreetmap.org/wiki/Image:IMG_6784.JPG http://wiki.openstreetmap.org/wiki/Image:IMG_6783.JPG ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
