Re: [Tagging] Urban perimeter
Could we define boundary=urban then? ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Urban perimeter
On Tue, May 27, 2014 at 5:55 PM, Martin Koppenhoefer dieterdre...@gmail.com wrote: I see, for this you'd most probably need a new boundary type (if it isn't the same as your administrative boundaries). +1 type=boundary + boundary=? Pieren ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Urban perimeter
2014-05-27 1:48 GMT+02:00 Fernando Trebien fernando.treb...@gmail.com: Hello everyone, From time to time there's a discussion in the Brazilian community on how to tag an urban perimeter. In Brazil, this is a legally defined area with some defined characteristics, such as: - different kind and level of environmental impact (and therefore different environmental policies) - slightly different taxation system for residents - different maxspeed on highways (mostly determined by being inside or outside of this perimeter) One user has suggested that we use settlement=yes (a proposed tag still not voted: http://wiki.openstreetmap.org/wiki/Proposed_features/Urban_settlements) for that purpose. I'd like to hear your opinions and suggestions. Several Brazilian users have mapped the entire urban extension (not exactly the same as the legally defined perimeter) in small cities and tagged it using landuse=residential, which is probably wrong in most cases and can be seen as tagging for the renderer. I believe they're probably expecting the same visual effect one gets from Google Maps and Here Maps: both draw a faint grey background over the urban area and is somewhat distinguishable at the border of most cities. (Whichever tag we go with, we would then ask rendering engine developers to replicate that visual effect.) I don't know in Brazil, but in Italy or Germany the maxspeed for built-up areas does not correspond perfectly with the settlement extension but is indeed yet another thing to consider. It is basically defined by street signs (start / end of a settlement according to the driving laws), and we map these signs on nodes aside the highway with traffic_sign=city_limit (name=*) and split the highway there and map the speed limit as maxspeed=50 (or whatever your default is) and source:maxspeed=IT:urban (or DE:urban etc.) http://wiki.openstreetmap.org/wiki/Key%3Asource%3Amaxspeed (we add those source:maxspeed tags so we could hypothetically adjust the speedlimit in case the law was changed, therefore we also suggest to map source:maxspeed=sign if there is an additional sign which confirms the default). For settlements (in urbanism / settlement geographic terms) my suggestion is to use place=* on an area. Please do not use landuse=residential for huge areas with all kind of landuses inside. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Urban perimeter
On Tue, May 27, 2014 at 7:18 AM, Martin Koppenhoefer dieterdre...@gmail.com wrote: For settlements (in urbanism / settlement geographic terms) my suggestion is to use place=* on an area. There is one problem when using place: people start to duplicate data. What is already present/available in the place node is duplicated in the place area. Sometimes it also causes data mismatch (population with one value in the node and a different one in the area, different classifications, names, etc). The urban perimeter tag should be as simple as possible, without giving a chance for data duplication. Please do not use landuse=residential for huge areas with all kind of landuses inside. Using landuse=residential is exactly what we want to avoid. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Urban perimeter
On Tue, May 27, 2014 at 7:18 AM, Martin Koppenhoefer dieterdre...@gmail.com wrote: I don't know in Brazil, but in Italy or Germany the maxspeed for built-up areas does not correspond perfectly with the settlement extension but is indeed yet another thing to consider. It is basically defined by street signs (start / end of a settlement according to the driving laws), and we map these signs on nodes aside the highway with traffic_sign=city_limit (name=*) and split the highway there and map the speed limit as maxspeed=50 (or whatever your default is) and source:maxspeed=IT:urban (or DE:urban etc.) http://wiki.openstreetmap.org/wiki/Key%3Asource%3Amaxspeed (we add those source:maxspeed tags so we could hypothetically adjust the speedlimit in case the law was changed, therefore we also suggest to map source:maxspeed=sign if there is an additional sign which confirms the default). That's essentially the same as in Brazil. Mapping the perimeter would not replace mapping maxspeeds for each way individually. For settlements (in urbanism / settlement geographic terms) my suggestion is to use place=* on an area. Wouldn't that make users confused when reading search results? The place=* tag is already used in cities' admin centre node and (sometimes, perhaps incorrectly) admin boundary relation. Please do not use landuse=residential for huge areas with all kind of landuses inside. That's precisely what we want to avoid. Maybe we need a new tag for that. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging -- Fernando Trebien +55 (51) 9962-5409 Nullius in verba. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Urban perimeter
I like Nelson's idea of using a new value for boundary to represent this, mainly because the perimeter is not ground truth but an invisible legal definition that roughly matches the urbanized area. I was wondering if this concept exists elsewhere so that we can even propose such value in a way that's reusable worldwide. Here Maps represents the urban perimeter in Brazil just like this dotted line across a river near Berlin and the area inside it: http://here.com/52.5804776,13.2183974,18,0,0,normal.day But in the case of Berlin, it could be Here Maps' arbitrary choice, not a legally significant area. On Tue, May 27, 2014 at 10:01 AM, Nelson A. de Oliveira nao...@gmail.com wrote: On Tue, May 27, 2014 at 7:18 AM, Martin Koppenhoefer dieterdre...@gmail.com wrote: For settlements (in urbanism / settlement geographic terms) my suggestion is to use place=* on an area. There is one problem when using place: people start to duplicate data. What is already present/available in the place node is duplicated in the place area. Sometimes it also causes data mismatch (population with one value in the node and a different one in the area, different classifications, names, etc). The urban perimeter tag should be as simple as possible, without giving a chance for data duplication. Please do not use landuse=residential for huge areas with all kind of landuses inside. Using landuse=residential is exactly what we want to avoid. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging -- Fernando Trebien +55 (51) 9962-5409 Nullius in verba. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Urban perimeter
2014-05-27 15:01 GMT+02:00 Nelson A. de Oliveira nao...@gmail.com: On Tue, May 27, 2014 at 7:18 AM, Martin Koppenhoefer dieterdre...@gmail.com wrote: For settlements (in urbanism / settlement geographic terms) my suggestion is to use place=* on an area. There is one problem when using place: people start to duplicate data. What is already present/available in the place node is duplicated in the place area. Sometimes it also causes data mismatch (population with one value in the node and a different one in the area, different classifications, names, etc). It is not really duplicating data, as the place on the node does not convey any information about the spatial extension of the place. This is essentially a relic from the early days of osm, interpreting a node is easier than a relation (and relations weren't even there when we already had mapped a lot of places). The nodes convey a different info though, that of a central spot, useful for rendering and for generic routing (without a specific address) or for computing distance tables. The solution on the long run could be to have place relations to combine the area with the place node. Duplicating data like population should be avoided, I agree. These are all well known issues, but it takes some time to sort this out. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Urban perimeter
2014-05-27 15:37 GMT+02:00 Fernando Trebien fernando.treb...@gmail.com: I like Nelson's idea of using a new value for boundary to represent this, mainly because the perimeter is not ground truth but an invisible legal definition that roughly matches the urbanized area. IMHO the extension of a settlement is ground truth and can be surveyed or gotten from aerial imagery. The legal boundary traffic-wise isn't a boundary actually, rather it is a lot of points (city limit signs) that locally define the boundary for that piece of road. As this is not needed for anything but traffic rules it would make more sense to map it to where it belongs (the individual roads). At least around here there is no such thing as a perimeter for inside / outside the settlement under traffic aspects, there are only points (and those are sometimes moved inward or outward the actual built-up area, just as it seems appropriate under traffic aspects). Cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Urban perimeter
On Tue, May 27, 2014 at 3:37 PM, Fernando Trebien fernando.treb...@gmail.com wrote: I like Nelson's idea of using a new value for boundary to represent this, mainly because the perimeter is not ground truth but an invisible legal definition that roughly matches the urbanized area. I was wondering if this concept exists elsewhere so that we can even propose such value in a way that's reusable worldwide. That's the point. Is it legal or just the sum of all urbanized landuse 's (residential, industrial, retail). Does it include backyards, garden, orchard, etc ? The limit is often clear on the road (first/last building + road sign) but fuzzy on aerial imagery if you want to draw the area. And if all landuses are already mapped, do you add a new polygon reusing existing nodes or do you create a multipolygon relation (splitting the existing landuse) or you just collect the sum of existing landuses ? Pieren ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Urban perimeter
On Tue, May 27, 2014 at 11:27 AM, Pieren pier...@gmail.com wrote: That's the point. Is it legal or just the sum of all urbanized landuse 's (residential, industrial, retail). Does it include backyards, garden, orchard, etc ? The limit is often clear on the road (first/last building + road sign) but fuzzy on aerial imagery if you want to draw the area. And if all landuses are already mapped, do you add a new polygon reusing existing nodes or do you create a multipolygon relation (splitting the existing landuse) or you just collect the sum of existing landuses ? The urban limit/boundary is legal (defined by law) here in Brazil. It may englobe areas that still lack a specific use or are not yet populated. It's not only a simple sum of the landuses. It determines, for example, the area that is taxed by the municipality (the urban perimeter/area) or by the federation (the rural area). Example: http://here.com/-22.3837691,-47.3933969,12,0,0,normal.day It's the greyish areas englobing the cities. About mapping it, I see it exactly as mapping administrative boundaries: reuse nodes/ways as needed (or as possible, or as wanted). ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Urban perimeter
2014-05-27 17:44 GMT+02:00 Nelson A. de Oliveira nao...@gmail.com: The urban limit/boundary is legal (defined by law) here in Brazil. It may englobe areas that still lack a specific use or are not yet populated. It's not only a simple sum of the landuses. It determines, for example, the area that is taxed by the municipality (the urban perimeter/area) or by the federation (the rural area). I see, for this you'd most probably need a new boundary type (if it isn't the same as your administrative boundaries). cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Urban perimeter
2014-05-27 17:53 GMT+02:00 Fernando Trebien fernando.treb...@gmail.com: The urban perimeter is a major factor used by transit authorities to establish maximum speeds, but not the only criteria for that. So yes, you do find a few high speed highways on the urban side and a few low speed areas on the rural side, but these are the exceptions basically you won't be able to use it for maxspeed then, maybe to check for improbable maxspeeds to re-survey, but not to add explicit maxspeeds to the db. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
