[Tagging] Tunnels and bridges
Hi! I'm looking for some alternatives to map tunnels and bridges that contain several ways. I'm not really happy with the proposed relation [1]. Is there any other approach for this? I'm asking myself why don't we simply map the outline of the bridge/tunnel (the latter may be more difficult to obtain), tag it with something like structure=bridge (or similar, maybe even building=bridge), bridge= (if necessary) and layer=x. Connect the ways running over the bridge to this structure, use the same layer tag and you're set. It is after all a physical object, so why don't we map it as such? I simply don't see any reason for a relation here. regards, Martin [1] http://wiki.openstreetmap.org/wiki/Relations/Proposed/Bridges_and_Tunnels ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
2013/1/31 Martin Vonwald > Hi! > > I'm looking for some alternatives to map tunnels and bridges that > contain several ways. I'm not really happy with the proposed relation > [1]. Is there any other approach for this? I'm asking myself why don't > we simply map the outline of the bridge/tunnel (the latter may be more > difficult to obtain), tag it with something like structure=bridge (or > similar, maybe even building=bridge), bridge= (if necessary) and > layer=x. Connect the ways running over the bridge to this structure, > use the same layer tag and you're set. It is after all a physical > object, so why don't we map it as such? I simply don't see any reason > for a relation here. > +1, I like building=bridge. Wikipedia says that a building is, "a structure used or intended for supporting or sheltering any use or continuous occupancy" In this case, it is supporting a road (and in case of Ponte Vecchio, it supports a footway and houses) But tunnel isn't a building, so maybe man_made=tunnel? I like this better than relations too. Janko Mihelić ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
2013/1/31 Martin Vonwald : > Hi! > > I'm looking for some alternatives to map tunnels and bridges that > contain several ways. I'm not really happy with the proposed relation > [1]. Is there any other approach for this? I'm asking myself why don't > we simply map the outline of the bridge/tunnel (the latter may be more > difficult to obtain), tag it with something like structure=bridge (or > similar, maybe even building=bridge), bridge= (if necessary) and > layer=x. Connect the ways running over the bridge to this structure, > use the same layer tag and you're set. It is after all a physical > object, so why don't we map it as such? I simply don't see any reason > for a relation here. +1, drawing the outline seems a good approach as it permits to group visually (and topologically) different carriageways running over the same bridge (as opposed to two parallel bridges). Actually a "classic" bridge will often have several outlines when the abutments are mapped separately, and then you would use layer-tags and maybe would want to also add the abutments to the bridge-object (in this case a relation might be needed). For tunnels I am not sure if there are situations with several carriageways in the same tube (in this case a common outline made sense IMHO, while 2 parallel tubes should be (IMHO) considered 2 tunnels. Tunnels also have the practical problem that you can't see their inside on aerial imagery and GPS doesn't work inside, but this is a different issue aside from tagging. Whether "building" is a nice key might be disputable (a bridge technically isn't a building, but a technical structure, on the other hand I have always argued that "building" in OSM is a generic tag for all kind structures and not only those intended for humans to live inside), but personally I'd approve it. If we decide to use building=* for bridges the * should be always the same value (e.g. "bridge") and not building=draw_bridge etc. (these details like bridge typology would go into subtags, allowing easy filtering of the bridges if you don't want to render them as buildings). These bridge-objects would also allow us to tag in an easy and standard way stuff like ref-numbers and bridge names (i.e. with "ref" and "name" and not requiring stuff like "bridge_name"...), have a common object to link WP-articles, etc. Cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On 31.01.2013 12:06, Martin Vonwald wrote: > I'm looking for some alternatives to map tunnels and bridges that > contain several ways. I'm not really happy with the proposed relation > [1]. Is there any other approach for this? I'm asking myself why don't > we simply map the outline of the bridge/tunnel (the latter may be more > difficult to obtain), tag it with something like structure=bridge (or > similar, maybe even building=bridge), bridge= (if necessary) and > layer=x. Connect the ways running over the bridge to this structure, > use the same layer tag and you're set. For starters, the relation means that you do not have to rely on layer tags to find out which elements are on the bridge/tunnel (or even on which bridge/tunnel in the case of intersecting bridges or tunnels). I do not really have faith that mappers will reliably add correct layers... The relation at least makes the relationship explicit and works just the same way e.g. for multi-level bridges. But then the relation is also a lot more flexible. As you already hinted at, it makes knowing the outline optional, which is useful for tunnels where you cannot easily see it from aerial imagery. It also lets you map the edges instead of or in addition to an outline. This makes it potentially a lot easier to achieve the desired rendering. The flexibility would further extend to possible future additions. For example individually mapped bridge piers, as have been proposed in the "bridge types" proposal, could be easily associated with the bridge by the relation. Association by layer wouldn't really work as these are _under_ the bridge. So I think that this is a case where a relation is actually a good representation. With a decent preset instead of our (unfortunately) massively-overcomplex relation editors, editing this could be pretty intuitive even for beginners. In my opinion, the fact that a bridge is a physical entity actually makes understanding the relation easier. Tobias ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On 31.01.2013 13:24, Janko Mihelić wrote: > I like building=bridge. Not a good choice imo. According to a recent discussion, mappers might want to use that tag specifically to map buildings built into bridges - like these: http://ampelmann-restaurant.de/content/images/1a162245ce191485484b155c6eae79b9.jpg Bridges also have to be handled completely differently in code than normal buildings for any remotely sophisticated rendering. So even if you want to avoid bridge relations (which I don't necessarily agree with, see my other mail), please choose a new, unambiguous key for the bridge outlines. Tobias ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
2013/1/31 Tobias Knerr : > On 31.01.2013 13:24, Janko Mihelić wrote: >> I like building=bridge. > > Not a good choice imo. According to a recent discussion, mappers might > want to use that tag specifically to map buildings built into bridges - > like these: > > http://ampelmann-restaurant.de/content/images/1a162245ce191485484b155c6eae79b9.jpg I wouldn't call this a "bridge", it is a vault, but the "bridge" (or viaduct) if you wanted to map it would (IMHO) be the structure as a whole, not just a single segment. > Bridges also have to be handled completely differently in code than > normal buildings for any remotely sophisticated rendering. So even if > you want to avoid bridge relations (which I don't necessarily agree > with, see my other mail), please choose a new, unambiguous key for the > bridge outlines. Yes, probably you would want to add a special treatment in rendering for bridges, but it wouldn't be necessary missleading or confusing to have them rendered the same way than a ordinary building. If there was a key "building=bridge" with a common usecase I won't see any ambiguity. There are bridge buildings, which don't carry roads or rails, like these: http://www.spiegel.de/pics/92/0,1020,1536992,00.jpg http://www.gropar.ch/typo3temp/pics/41b05acade.jpg http://www.schoendorfer.de/neu/baustellen/zollamt_walserberg/bilder/01.jpg and every building built on stuilts might structurally be a bridge but I still don't see the problem, you would distinct these by looking whether there is a road going over them on the same layer (ok, there might be a bridge-like building with a road on top of it, in this case you'd probably need the relation, but the relation would be useful anyway, this is not necessarily an alternative to relations in all situations, but could make them unneccesary in many cases)). cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On Thu, Jan 31, 2013 at 2:06 PM, Martin Koppenhoefer wrote: > > I wouldn't call this a "bridge", it is a vault, but the "bridge" (or > viaduct) if you wanted to map it would (IMHO) be the structure as a > whole, not just a single segment. Instead of "building=bridge", you might choose "man_made=bridge_deck" or simply "bridge=deck" ? Btw, the idea is not new. Check this bridge I traced in march 2010: http://www.openstreetmap.org/browse/way/53582123/history I used the tags combination "highway=bridge" + "area=yes". Then it was replaced by "bridge=yes" + "area=yes" and finally by "building=bridge". I guess the "building=*" tag is used for rendering purpose. Which is not correct. Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On 31/01/2013 12:37, Martin Koppenhoefer wrote: drawing the outline seems a good approach as it permits to group visually (and topologically) different carriageways running over the same bridge (as opposed to two parallel bridges). This is approach is used by IHO for marine chart data. Where a bridge has more than span, they further divide the bridge outline into two or more butted polygons, one for each span, so that each span can have its own height & width attributes. They also map bridge piers as separate objects. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
2013/1/31 Pieren : > On Thu, Jan 31, 2013 at 2:06 PM, Martin Koppenhoefer > wrote: >> >> I wouldn't call this a "bridge", it is a vault, but the "bridge" (or >> viaduct) if you wanted to map it would (IMHO) be the structure as a >> whole, not just a single segment. > > Instead of "building=bridge", you might choose "man_made=bridge_deck" > or simply "bridge=deck" ? the bridge deck is not the whole bridge, it is only the surface of the bridge. You would still need an object to represent the whole bridge. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
In my opinion this is a rather obvious approach therefore I'm not surprised that someone already came up with it earlier. But I am definitively surprised that we don't have any documentation in the wiki for it. I see a lot of bridges with many ways running over it (two footways, two cycleways, two carriageways) and on the map it just looks AWFUL! But the renderer can not display it any better because it doesn't have the appropriate information. So I would suggest that we decide which tag would be good for the bridge, document it and start tagging it this way to get things going ;-) Let's first concentrate on bridges. In my opinion we need the following tags: * bridge= : use this tag just like it is used at the moment. If the value would be "yes" it should be optional. * layer= : this should get the same layer as the ways running over it. One could argue that this should get a layer below the ways, but I find this rather counter-intuitive. See comment below! * =bridge : this is the tag we should decide one. I guess the value "bridge" is unchallenged. So for a simple bridge we would end up with one way describing the outline and 2-3 tags. Concerning the layer-tag we have to consider something more: how about bridges with more than one level, e.g. on top are the roads and below them the subway and some cycleways. There is already a concept that supports this: building-parts. It might be a good idea to integrate bridges in this concept. I am definitively not familiar with that concept but if I am not mistaken one can specify different levels of a building. So if we would use that concept we could specify a bridge with two levels with the tags level=1 + layer= for the lower part and level=2 + layer= for the upper part. The tagging of the "simple" case (i.e. with only one level) wouldn't change. Any experts here for 3D tagging? Would a bridge fit into this concept? regards, Martin 2013/1/31 Pieren : > On Thu, Jan 31, 2013 at 2:06 PM, Martin Koppenhoefer > wrote: >> >> I wouldn't call this a "bridge", it is a vault, but the "bridge" (or >> viaduct) if you wanted to map it would (IMHO) be the structure as a >> whole, not just a single segment. > > Instead of "building=bridge", you might choose "man_made=bridge_deck" > or simply "bridge=deck" ? > > Btw, the idea is not new. Check this bridge I traced in march 2010: > http://www.openstreetmap.org/browse/way/53582123/history > > I used the tags combination "highway=bridge" + "area=yes". Then it was > replaced by "bridge=yes" + "area=yes" and finally by > "building=bridge". > I guess the "building=*" tag is used for rendering purpose. Which is > not correct. > > 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] Tunnels and bridges
Am 31.01.2013 14:44, schrieb Martin Vonwald: In my opinion this is a rather obvious approach therefore I'm not surprised that someone already came up with it earlier. But I am definitively surprised that we don't have any documentation in the wiki for it. I see a lot of bridges with many ways running over it (two footways, two cycleways, two carriageways) and on the map it just looks AWFUL! But the renderer can not display it any better because it doesn't have the appropriate information. So I would suggest that we decide which tag would be good for the bridge, document it and start tagging it this way to get things going ;-) Let's first concentrate on bridges. In my opinion we need the following tags: * bridge= : use this tag just like it is used at the moment. If the value would be "yes" it should be optional. +1 for using bridge=type, -1 for defining it as optional. * layer= : this should get the same layer as the ways running over it. One could argue that this should get a layer below the ways, but I find this rather counter-intuitive. See comment below! +1 for setting it the same layer as the ways running over it. Using even more layers would increase the confusion when using more than one layer (two if you count the "default" one), as it would double the layers. Especially it would require changes to existing layers when "extending" existing bridges with the bridge-building-area proposed here. One remark where you don't provide a solution, but where I don't have any solution either is the other way around: You/we propose here a way to define "these ways share one bridge structure", but it's plugged in to the existing osm database, so there are already many bridges where the bridge area would fit, but is missing (as it wasn't defined/proposed up to now). If we would propose a solution to state "this is single-way-bridge as it is mapped here currently", QA tools could check both variants for completeness instead of asking ever and ever again something like "these n bridges run approximately in parallel near to each other. If the ways share the same structure, please add a [bridge-area] for the area covered by the bridge structure." To solve that probably an additional tag for "single" bridges would be useful: standalone_bridge=yes (I don't like the wording here, but you get the point). As a second remark I would like to ask how to define the bridges pillars (in the middle or at both ends of the structure). Being able to map them would allow 1) better 3D rendering 2) interpreting them as barriers under the bridge 3) more or less calculate an estimated space width for driving through under the bridge regards Peter 2013/1/31 Pieren : On Thu, Jan 31, 2013 at 2:06 PM, Martin Koppenhoefer wrote: I wouldn't call this a "bridge", it is a vault, but the "bridge" (or viaduct) if you wanted to map it would (IMHO) be the structure as a whole, not just a single segment. Instead of "building=bridge", you might choose "man_made=bridge_deck" or simply "bridge=deck" ? Btw, the idea is not new. Check this bridge I traced in march 2010: http://www.openstreetmap.org/browse/way/53582123/history I used the tags combination "highway=bridge" + "area=yes". Then it was replaced by "bridge=yes" + "area=yes" and finally by "building=bridge". I guess the "building=*" tag is used for rendering purpose. Which is not correct. 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 ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On 31.01.2013 14:06, Martin Koppenhoefer wrote: > 2013/1/31 Tobias Knerr : >> http://ampelmann-restaurant.de/content/images/1a162245ce191485484b155c6eae79b9.jpg > > I wouldn't call this a "bridge", it is a vault, but the "bridge" (or > viaduct) if you wanted to map it would (IMHO) be the structure as a > whole, not just a single segment. I don't want to discuss that example specifically. I just wanted to point out that a value of a key - such as building - that explicitly permits "user defined" values and is regularly used in very creative ways isn't reliable enough for this very specific task. You see, mappers are using building values very loosely, almost as a free-text field. Mappers are using layers very loosely, too, often as a rendering hint or with very exotic interpretations. I fear that the combined effect would turn this suggested mapping style into fuzzy guesswork. > in this case > you'd probably need the relation, but the relation would be useful > anyway, this is not necessarily an alternative to relations in all > situations, but could make them unneccesary in many cases)). Yes, the relation is only truly necessary in some cases, but these cases exist. So you are essentially suggesting a third, "medium complexity" tagging style between the simple (bridge=yes) and the complex (bridge relation) style. However, there is a point where adding *even more* options on how to tag the very same thing makes documentation so much more convoluted and creating convenient editor support for all the options so much harder that it outweighs any usability advantages the "medium complexity" option might have offered. I can't stop you from following that road. But I believe that, by following the short-term goal to create a limited tagging scheme that can be more easily used with today's editors - instead of solving the problem at the root by improving relation presets -, you will ultimately make things more confusing overall and make it harder for data consumers to support all the tagging variants in use. Tobias ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On 31/01/2013 13:44, Martin Vonwald wrote: * bridge= : use this tag just like it is used at the moment. If the value would be "yes" it should be optional. Again, borrowing from IHO, they define the following bridge types: fixed opening swing lifting bascule pontoon drawbridge transporter foot viaduct aqueduct suspension ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On Thu, Jan 31, 2013 at 2:44 PM, Martin Vonwald wrote: > * =bridge : this is the tag we should decide one. I guess > the value "bridge" is unchallenged. My 2 cents: - area=bridge - area:bridge=yes - man_made=bridge - amenity=bridge (I'm joking) Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
2013/1/31 Pieren : > On Thu, Jan 31, 2013 at 2:44 PM, Martin Vonwald wrote: > >> * =bridge : this is the tag we should decide one. I guess >> the value "bridge" is unchallenged. > > My 2 cents: > - area=bridge > - area:bridge=yes > - man_made=bridge > - amenity=bridge (I'm joking) All fine, but think about my comment about different levels of a bridge. We already have a supported tagging scheme for this, why not reuse it? And if I'm not mistaken this would lead to building=bridge . We really should get some help from the 3D experts here. I'm not a fan of reinventing the wheel ;-) ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On 31/01/2013 13:44, Martin Vonwald wrote: * =bridge : this is the tag we should decide one. I guess the value "bridge" is unchallenged. -1 If the primary tag is bridge=, then why do we need the above tag at all? ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
2013/1/31 Malcolm Herring : > On 31/01/2013 13:44, Martin Vonwald wrote: >> >> * =bridge : this is the tag we should decide one. I guess >> the value "bridge" is unchallenged. > > > -1 > If the primary tag is bridge=, then why do we need the above tag at > all? The key "bridge" is currently used to specify that something else is on a bridge, e.g. highway=motorway + bridge=yes. The value of the key bridge specifies the type of the bridge. We should try not to change the meaning of a tag too much. Therefore I would suggest: * =bridge ---> this is a bridge * bridge= ---> this is a bridge of type (same meaning as now) Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
Martin, Maybe I am missing something from your proposal. I had understood it to mean that bridges should be mapped as distinct features, separate from the ways that pass over and under. Therefore, "bridge=..." tags on the ways would become redundant and remove the ambiguity and messy rendering that they cause when more than one way crosses the same bridge. Also, wheat exactly did you mean by "Connect the ways running over the bridge to this structure"? This implies a relation to make the connections, but you then go on to deprecate the use of relations. So I am confused! Malcolm ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On Thu, Jan 31, 2013 at 3:51 PM, Malcolm Herring wrote: > Maybe I am missing something from your proposal. I had understood it to mean > that bridges should be mapped as distinct features, separate from the ways > that pass over and under. Therefore, "bridge=..." tags on the ways would > become redundant and remove the ambiguity and messy rendering that they > cause when more than one way crosses the same bridge. Yes. Use "bridge=*" only once, either on the highway way (linear) or on a polygon (surface). But it's preferable to use a second tag to distinguish the linear vs the surface modeling. Otherwise we don't know if an OSM closed way tagged "bridge=yes" is the surface or something really linear where the "highway" tag is missing. > Also, wheat exactly did you mean by "Connect the ways running over the > bridge to this structure"? This implies a relation to make the connections, > but you then go on to deprecate the use of relations. I guess it's just about a node put on the intersection between the highway(s) and the polygon. But I'm not sure if this is really required (the same question raises when a highway is crossing an administrative boundary or a landuse). Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
2013/1/31 Malcolm Herring : > Martin, > > Maybe I am missing something from your proposal. No proposal - just ideas ;-) >I had understood it to mean > that bridges should be mapped as distinct features, separate from the ways > that pass over and under. Therefore, "bridge=..." tags on the ways would > become redundant and remove the ambiguity and messy rendering that they > cause when more than one way crosses the same bridge. I would not do that. I would keep the bridge=xxx tags for backward compatibility. > Also, wheat exactly did you mean by "Connect the ways running over the > bridge to this structure"? This implies a relation to make the connections, > but you then go on to deprecate the use of relations. I meant: at the edges of the "structure" connect the OSM ways of the roads/ways to the OSM way of the "structure". As you already need to split the roads at the edges of the structure, because you need to add the layer (and bridge) key within the structure, there are already nodes present - just connect them with the OSM way of the structure. regards, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
I even drew it: http://i.imgur.com/uk5RXjL.png So, a renderer could find out if a road that has the tag bridge=yes is connected to a way that has a tag building=bridge on both ends. If it is, it doesn't render the black lines on left and right of road. That's why I think it's better not to remove the tag bridge=yes from roads that have the bridge area around them. Janko Mihelić ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On 31.01.2013 16:24, Janko Mihelić wrote: > I even drew it: > http://i.imgur.com/uk5RXjL.png > > So, a renderer could find out if a road that has the tag bridge=yes is > connected to a way that has a tag building=bridge on both ends. If it > is, it doesn't render the black lines on left and right of road. That's > why I think it's better not to remove the tag bridge=yes from roads that > have the bridge area around them. It will not be possible for every way on top of the bridge to share nodes with the outline. You may have to split the way across the bridge because one of its attributes changes - you will end up with ways contained within, but not connected to the outline. Tobias ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On Thu, Jan 31, 2013 at 4:17 PM, Martin Vonwald wrote: > I would not do that. I would keep the bridge=xxx tags for backward > compatibility. Bad idea. I like the principle "one feature, one OSM element". Solve rendering issues in the rendering toolchain. Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
2013/1/31 Tobias Knerr > > It will not be possible for every way on top of the bridge to share > nodes with the outline. > You are right, it's a bit more complicated than what I described. 2013/1/31 Pieren > > Bad idea. I like the principle "one feature, one OSM element". Solve > rendering issues in the rendering toolchain. > Well, having building=bridge and bridge=yes isn't two features. First one is "the" feature (bridge) and the second one is the road with an attribute (it is on a bridge). They are redundant, but I wouldn't call them duplicated. Janko Mihelić ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
For Mapnik it might be even more simple, but I'm not sure. Currently Mapnik as far as I know draws the following (in order): bridges: 1) bridge-casing 2) highway-casing (is that rendered on bridges currently? 3) bridge-fill 4) highway-fill 5) highway-label we now propose to add the bridge-area. If bridge-fill is the same for the current rendering than for the bridge-areas we propose, this would lead to this valid rendering order (kept numbers for hopefully better readability): 0) bridge area casing 1) bridge-casing 1a) bridge-area-fill 2) highway-casing 3) bridge-fill 4) highway-fill 5) highway-label If there's no bridge-area defined, the rendering results exactly the same as before (ignore 0 and 1a and it's the same as above). If there is a bridge-area, then with this rendering ruleset and given, that bridge-fill is not transparent - any bridge-casing is covered and thus overwritten by the bridge-area-fill - the highway is rendered above as if the bridge tag would have been ignored on it (sequence 2, 4, 5) regards Peter Am 31.01.2013 16:24, schrieb Janko Mihelic': I even drew it: http://i.imgur.com/uk5RXjL.png So, a renderer could find out if a road that has the tag bridge=yes is connected to a way that has a tag building=bridge on both ends. If it is, it doesn't render the black lines on left and right of road. That's why I think it's better not to remove the tag bridge=yes from roads that have the bridge area around them. Janko Mihelic' ___ 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] Tunnels and bridges
Am 31.01.2013 16:57, schrieb Janko Mihelić: Well, having building=bridge and bridge=yes isn't two features. First one is "the" feature (bridge) and the second one is the road with an attribute (it is on a bridge). They are redundant, but I wouldn't call them duplicated. They are duplicated if you follow the old scheme, where bridge=yes in fact was "this is a bridge - or part of a bridge". But on the other hand if you follow the old scheme (and we don't use building=bridge for the area, as stated dangerous above because of the nearly-free-text-character of building=*) you would completely ignore the bridge area, and thus you don't get a duplicate again. For the future that would mean: "man_made=bridge (or whatever) means, that this area is a bridge (analogon: building)" "bridge=yes means, if you are going/driving on that way, you go/drive over a bridge" Please note: The second sentence was true in the past, too. For data consumers not dealing with the new scheme it follows: nothing changed (except probably naming, which was a problem already with the name-conflict between highways and bridges name). For data consumers supporting the new it follows: If there's no bridge-area (e.g. man_made=bridge) defined, but there's a bridge=yes, I have to assume an error, I might report that as such and/or I should fall back to assume a bridge-area at/around the way, which is simple by creating a rectangle with the assumed bridge width around the way. regards Peter ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
2013/1/31 Martin Vonwald :
> In my opinion this is a rather obvious approach therefore I'm not
> surprised that someone already came up with it earlier. But I am
> definitively surprised that we don't have any documentation in the
> wiki for it.
there are real examples, e.g. these two:
http://www.openstreetmap.org/browse/way/42922473
http://www.openstreetmap.org/browse/way/44097288
which started with bridge=area and name=* but were "fixed" in the
meantime ("fix nonconforming uses of bridge tag")
;-)
cheers,
Martin
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Re: [Tagging] Tunnels and bridges
I read a bit about 3D buildings, and it's pretty compatible. Here is an article about simple 3D buildings: http://wiki.openstreetmap.org/wiki/Simple_3D_Buildings Here is a picture that shows the concept of building:parts: http://wiki.openstreetmap.org/w/index.php?title=File:Minlevel.svg&page=1 Those three are building parts (building:part=yes), and they are all in a relation that has type=building. A full area (building=yes) is also in the relation. So with a bridge, we could have the relation with type=building, in it would be the full area with building=bridge, and piers which would all have building:part=yes (or maybe building:part=pier). Each pier would have it's height (height=10). We should agree what to do with the height (and min_height) of the building=bridge area. If it goes over uneven terrain, there is no unique height. If it goes over sea, than we have tides that change the height. So we can agree to put in the maximum height the bridge has, or nothing. I see no other solution. Janko Mihelić ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On Thu, Jan 31, 2013 at 5:13 PM, Peter Wendorff wrote: > For data consumers supporting the new it follows: If there's no bridge-area > (e.g. man_made=bridge) defined, but there's a bridge=yes, I have to assume > an error, I might report that as such and/or I should fall back to assume a > bridge-area at/around the way, which is simple by creating a rectangle with > the assumed bridge width around the way. For me, it's clearly duplicates. Like keeping the "amenity=parking" node when you draw the parking polygon. Or keeping "abutters=residential" on the highway when you draw the "landuse=residential" polygon. Or it's just for backward compatibility, like keeping "natural=water" on "waterway=riverbank" until mapnik stylesheet rendered correctly riverbanks... Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On 31/01/2013 15:17, Martin Vonwald wrote: As you already need to split the roads at the edges of the structure, because you need to add the layer (and bridge) key within the structure, there are already nodes present - just connect them with the OSM way of the structure. Why do you need split the road at the edges of the bridges? This is currently done because it is the only way of defining the bridge. If we are to split the two features, then this need disappears. If the bridge crossing ways have width or weight limits, these do not necessarily coincide with the structural limits of the bridges. They often apply to the approaches as well, so the section of the road where the restriction applies begins and ends beyond the bridge. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
+1 Not splitting the way for every bridge will make tagging a lot easier. Often when things such as speed limits on long sections of road, bridges get missed and then often the cause of extra routing instructions if a reference tag is missing. Phil (trigpoint) -- Sent from my Nokia N9 On 31/01/2013 17:14 Malcolm Herring wrote: On 31/01/2013 15:17, Martin Vonwald wrote: > As you already need to > split the roads at the edges of the structure, because you need to add > the layer (and bridge) key within the structure, there are already > nodes present - just connect them with the OSM way of the structure. Why do you need split the road at the edges of the bridges? This is currently done because it is the only way of defining the bridge. If we are to split the two features, then this need disappears. If the bridge crossing ways have width or weight limits, these do not necessarily coincide with the structural limits of the bridges. They often apply to the approaches as well, so the section of the road where the restriction applies begins and ends beyond the bridge. ___ 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] Tunnels and bridges
On 1/31/13 12:39 PM, Philip Barnes wrote: +1 Not splitting the way for every bridge will make tagging a lot easier. Often when things such as speed limits on long sections of road, bridges get missed and then often the cause of extra routing instructions if a reference tag is missing. it will make validation harder, though, when roads on different layers cross but one of them doesn't have a layer tag. not a lot harder, i think, but it will have an impact. richard ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On 31.01.2013 17:31, Janko Mihelić wrote: > I read a bit about 3D buildings, and it's pretty compatible. Here is an > article about simple 3D buildings: > > http://wiki.openstreetmap.org/wiki/Simple_3D_Buildings I think you are overlooking several problems. To start with, building:part cannot do arcing structures - like many bridge decks. They can also not easily to structures that become wider or narrower towards the top - like some bridge piers. While you could probably model a crude bridge shape with building:part, I would not have imagined that they would be used for bridges. Maybe it's possible, but they were designed as volume shapes. That is, as "blocks" where the interesting stuff is inside, rather than on top. Also note that "Simple 3D Buildings" doesn't have an established solution for ways on top of the roof yet. With normal buildings, that's a niche use case that would be good for, say, gardens or parking areas on the roof. But if you think of bridges as buildings (a style of thinking I'm not particularly comfortable with), this is essential, as you almost always have highways/railways on top of the "roof" then. I'm wondering whether the approach you describe has some merit nevertheless - because after all, many bridges do incorporate towers or other building structures - but I feel it should not be used as the primary approach to modelling bridges. > We should agree what to do with the height (and min_height) of the > building=bridge area. If it goes over uneven terrain, there is no unique > height. For the record, the height of a building mapped according to "Simple 3D Buildings" is always based off the point where terrain is the lowest. Tobias ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On 1/31/13 12:53 PM, Richard Welty wrote: On 1/31/13 12:39 PM, Philip Barnes wrote: +1 Not splitting the way for every bridge will make tagging a lot easier. Often when things such as speed limits on long sections of road, bridges get missed and then often the cause of extra routing instructions if a reference tag is missing. it will make validation harder, though, when roads on different layers cross but one of them doesn't have a layer tag. not a lot harder, i think, but it will have an impact. and it occurs to me that we need to account for cases like the George Washington Bridge between Manhattan and New Jersey, which has multiple decks carrying vehicle traffic. richard ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On 31.01.2013 18:39, Philip Barnes wrote: > Not splitting the way for every bridge will make tagging a lot easier. Won't anybody think of the poor renderers? :( Until now we could rely on the assumption that every way is *either* on the ground *or* above the ground. Which is pretty helpful imo. Tobias ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
Am 31.01.2013 18:14, schrieb Malcolm Herring: On 31/01/2013 15:17, Martin Vonwald wrote: As you already need to split the roads at the edges of the structure, because you need to add the layer (and bridge) key within the structure, there are already nodes present - just connect them with the OSM way of the structure. Why do you need split the road at the edges of the bridges? This is currently done because it is the only way of defining the bridge. If we are to split the two features, then this need disappears. If the bridge crossing ways have width or weight limits, these do not necessarily coincide with the structural limits of the bridges. They often apply to the approaches as well, so the section of the road where the restriction applies begins and ends beyond the bridge. +0.5 I agree that this is nice in future, but for compatibility reasons I would propose a slow progress towards what you describe: if the bridge is already there the ways are splitted, the bridge highway is already there and so on - so: keep them splitted and it's less work with more backwards compatibility. If they are not, it's up to you as a mapper if you want outdated renderers to use the old scheme or not. regards Peter ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
2013/1/31 Tobias Knerr > > I think you are overlooking several problems. To start with, > building:part cannot do arcing structures - like many bridge decks. They > can also not easily to structures that become wider or narrower towards > the top - like some bridge piers. > Anything more complicated than prisms for piers and areas for bridge decks is not a problem to be solved in openstreetmap IMHO. That is a job for 3D building models in other databases. > Also note that "Simple 3D Buildings" doesn't have an established > solution for ways on top of the roof yet. With normal buildings, that's > a niche use case that would be good for, say, gardens or parking areas > on the roof. But if you think of bridges as buildings (a style of > thinking I'm not particularly comfortable with), this is essential, as > you almost always have highways/railways on top of the "roof" then. > I think that connecting a road with the bridge area (with sharing nodes) is enough to tell the renderer that a road is on this plane. For the record, the height of a building mapped according to "Simple 3D > Buildings" is always based off the point where terrain is the lowest. I am thinking that this could deserve it's own type=bridge (instead of type=building) tag for a relation. It would help renderers make unique rules for rendering bridges. We could put specialized tags on piers like pier:top=arch, pier:top:width=3, or who knows what else. Janko Mihelić ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
On 31.01.2013 12:06, Martin Vonwald wrote: I'm looking for some alternatives to map tunnels and bridges that contain several ways. I'm not really happy with the proposed relation -1 The current method is used and well established since years and for my point of view works fine. So I clearly dislike to change it. Just my 2 cents, Michael. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
Am 01.02.2013 um 00:01 schrieb Michael Kugelmann : > On 31.01.2013 12:06, Martin Vonwald wrote: >> I'm looking for some alternatives to map tunnels and bridges that >> contain several ways. I'm not really happy with the proposed relation > -1 > The current method is used and well established since years and for my point > of view works fine. So I clearly dislike to change it. What current method do you refer to? The key bridge or the proposed relation? When reading through the responses in this thread I get the impression that there is need for a simple way to specify what OSM-ways belong to one, single bridge. Regarding the relation: there was a short discussion about a waterpark short time ago. It was asked if all the features should go into a site relation. The answer was (as I remember it): no. Only if the features are spread over different places. We have a spatial database so if all features are within a closed way there is no need for a relation. Why is there a different reasoning for a bridge? Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Tunnels and bridges
Hi, A few problems with the current approach: 1) When several things pass over the same bridge (eg, highway=secondary, highway=cycleway and highway=footway; or even just two independent lanes), renderers currently draw multiple bridges. 2) In areas where structures (buildings, paved areas, piers, riverbanks) are mapped precisely, bridges can't be - they're assumed to be the width of a standard road. 3) Bridges have distinct properties (name, height, etc) that can't be modelled properly because bridges don't actually exist. Tags like bridge_name are a kludge that don't work in cases like 1). These are all problems worth fixing. The solution seems to be: a) (Optional Create a relation that can group things together (type=bridge, or something more general if there's something good) b) (Optional) Create a closed way for the bridge itself, and tag it with a new tag (probably man_made=bridge would be best, because it would be better rendered by naive renderers than say building=bridge) c) (Optional) Add the bridge, if mapped, to the relation. It seems that every time this topic comes up, people want to go too far, and find general solutions (eg, solving both bridges and tunnels at once with "across" and "over" relation memberships), and start solving other problems too (eg, 3D buildings, not splitting ways when they pass over bridges...). It all gets complicated, and everyone gives up. But the solution above is pretty simple, and doesn't require breaking anything, and is totally optional. Map the way you do currently if you want, or also map the bridge separately if you want, or use a relation, or both. Steve On Fri, Feb 1, 2013 at 10:01 AM, Michael Kugelmann wrote: > On 31.01.2013 12:06, Martin Vonwald wrote: >> >> I'm looking for some alternatives to map tunnels and bridges that >> contain several ways. I'm not really happy with the proposed relation > > -1 > The current method is used and well established since years and for my > point of view works fine. So I clearly dislike to change it. > > > Just my 2 cents, > Michael. > > > > ___ > Tagging mailing list > Tagging@openstreetmap.org > http://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
