Re: [Tagging] Opinion on meaning of tracktype, smoothness and surface for routing
On 2014-03-20 15:29, Martin Koppenhoefer wrote : 2014-03-20 15:02 GMT+01:00 André Pirard a.pirard.pa...@gmail.com: Following a gentle dispute on OSM-talk-be about the class of a particular road, I pointed out without any follow-up that road classification (primary ... tertiary, as well as national ... local on IGN maps) is very subjective but that the road width is very objective. yes, the highway classification is slightly subjective but as osm shows, the cloud can usually find a commonly accepted values, so this doesn't seem to be a real problem (also because it doesn't really matter if a road is classified as secondary rather than primary, and more than one class up or down is usually not the range up to discussion). The problem comes with such roads as Belgian N674 which is uniformly classified as national on IGN official maps. On the eastern part, it's worth the primary status for through, heavy traffic. On the center part, it's certainly only secondary. But on the part going NW it's a dangerous road. And, despite its official status, only its 5 m width and bends can show that : 2.5 m wide lorries can't cross each other and they step on the verge. The road once crumbled down into the meadow below and is waiting for the next turn. Even cars must break and make a brisk turn. It would be nice that OSM routing avoided that road. Of course everybody is free to add a road width as well, there is the tag "width" for this, and also the tag "lanes". Unfortunately until now, only 5% of all highway-elements (admittedly not only roads) have the tag lanes and 1% has the tag width. The width would come as a complementary information: avoid it despite a gentle official classification apparency. Moreover, the width can be very easily measured with JOSM on Bing. you should be careful with the spherical mercator projection though, you might end up with different widths for the same width due to different latitudes, I am not sure how precise those measurements in JOSM actually are (some time ago they weren't but maybe this is fixed now). Good point that would have to be analyzed. Especially if there's a difference between NS and EW measurements! Of course, the closely related parameter is speed. related to width? I do not think there is a close relation, at least not a reliable one. Speed (to drive safely) is not intrinsic but in fact a consequence of other factors, including narrow width. Or it can be enforced. While reading your texts, I've had a crazy idea: measuring vibration in the car. There are Android vibration measuring programs like Vibration Monitoring. Alas, car vibration is very much dependent on car suspension. But would some of us experiment this or another idea and come up with a solution? this sounds interesting indeed, while I agree that it mostly depends on the car suspension. With (unsuspended) bicycles this would be more reliable I guess, but still the ability of the driver / rider to avoid holes in the surface might make a huge difference (e.g. in Rome there are some very bad roads with profund holes that get tapped every now and then but later reopen due to the heavy traffic. If you are on roads that you drive often you almost automatically get the habit of avoiding them, also at higher speeds, because you know their exact locations by mind). Yes, dodging the suspension would be the idea, see next. On 2014-03-20 23:18, David Bannon wrote : If we wanted to measure vibration I guess we could have a process to calibrate individual car's suspension. Maybe something like
Re: [Tagging] Opinion on meaning of tracktype, smoothness and surface for routing
On Fri, Mar 21, 2014 at 11:24 AM, André Pirard a.pirard.pa...@gmail.comwrote: The problem comes with such roads as Belgian N674http://www.openstreetmap.org/way/72502906#map=17/50.53927/5.64976which is uniformly classified as national on IGN official maps. On the eastern part, it's worth the primary status for through, heavy traffic. On the center part, it's certainly only secondary. But on the part going NW it's a dangerous road. And, despite its official status, only its 5 m width and bends can show that : 2.5 m wide lorries can't cross each other and they step on the verge. The road once crumbled down into the meadow below and is waiting for the next turn. Even cars must break and make a brisk turn. It would be nice that OSM routing avoided that road. Sounds like a reasonably well equipped routing engine would naturally avoid it if there's a better alternate available just based on the number and radius of curves, classification of the roadway, surface type, and the vehicle being driven. Bonus if horizontal and vertical limitations of the roadway are mapped and the routing engine is aware of the x, y and z dimensions of the vehicle in question (which is why I see a lot of driverless vehicle technology being more practical for navigation assistance for human drivers than as a fully autonomous vehicle). Of course everybody is free to add a road width as well, there is the tag width for this, and also the tag lanes. Unfortunately until now, only 5% of all highway-elements (admittedly not only roads) have the tag lanes and 1% has the tag width. The width would come as a complementary information: avoid it despite a gentle official classification apparency. Does anyplace outside North America subjectively tag highway=* or is it formally tied to the official classification in most places, such as it is in the UK? Moreover, the width can be very easily measured with JOSM on Bing. you should be careful with the spherical mercator projection though, you might end up with different widths for the same width due to different latitudes, I am not sure how precise those measurements in JOSM actually are (some time ago they weren't but maybe this is fixed now). Good point that would have to be analyzed. Especially if there's a difference between NS and EW measurements! I would also be interested in hearing if the JOSM measurement tools are currently maintained to be accurate. Granted, I'm not expecting it to be as accurate as finding some survey marks on either verge and start running survey lines (for a couple reasons, 1) A digital theodolite, it's accessories, getting licensed as a traffic control engineer, filing permits and putting out traffic control devices to do so safely and accurately is probably beyond the reach of almost everyone here besides the parallel universe me that won the Powerball jackpot and now has nothing better to do; and 2) most available aerial imagery, when properly aligned, seems to be getting us a horizontal dilution of precision within the resolution of the imagery or better on objects created by relatively skilled and experienced mappers (based on triangulation from known survey markers to known points and lines when I've had the access to professional surveying equipment). Of course, the closely related parameter is speed. related to width? I do not think there is a close relation, at least not a reliable one. Speed (to drive safely) is not intrinsic but in fact a consequence of other factors, including narrow width. Or it can be enforced. In some places, quite strictly. Oklahoma will write you up for 76 in a 75 maxspeed or 39 in a 40 minspeed. The resulting speed uniformity does make Oklahoma one of the easier states to drive in, assuming your driving personality is more positive than chaotic neutral on either or both axes (otherwise, it tends to be expensive, dangerous or both). While reading your texts, I've had a crazy idea: measuring vibration in the car. There are Android vibration measuring programs like Vibration Monitoring. Alas, car vibration is very much dependent on car suspension. But would some of us experiment this or another idea and come up with a solution? this sounds interesting indeed, while I agree that it mostly depends on the car suspension. With (unsuspended) bicycles this would be more reliable I guess, but still the ability of the driver / rider to avoid holes in the surface might make a huge difference (e.g. in Rome there are some very bad roads with profund holes that get tapped every now and then but later reopen due to the heavy traffic. If you are on roads that you drive often you almost automatically get the habit of avoiding them, also at higher speeds, because you know their exact locations by mind). Yes, dodging the suspension would be the idea, see next. Even on a fixed-fork hardtail bicycle, ride quality is still drastically affected by tire pressure,
Re: [Tagging] Opinion on meaning of tracktype, smoothness and surface for routing
Why 40, or why 50? Are these sensible choices for ways like those below? * http://cdn.c.photoshelter.com/img-get/ILEZumn6Zhqo/s/900/900/ERITREA-00085-BC3.jpg * http://www.mongolia-travel-guide.com/image-files/mrm-mongolia-main-road.jpg * http://www.horizonsunlimited.com/tstories/duval/images/037%20IMG_3494.jpg * http://farm3.staticflickr.com/2434/3897036578_12207239a3_o.jpg * http://i37.tinypic.com/r74ro0.jpg * http://www.ecosystema.ru/08nature/world/64ang/01.jpg * http://www.orderofmalta.int/wp-content/uploads/2011/07/Congo-new-road-MI-small.jpg * http://beta.images.theglobeandmail.com/archive/00539/Road-1_jpg_539581gm-b.jpg * http://codigolivre.net/wp-content/uploads/buracos-estrada.jpg Take a look at the descriptions of tracktype, smoothness and surface tag on the wiki, think about what their worst values are talking about and about how widely each value of the surface tag can vary in meaning for applications. Some people wouldn't even dare to try traveling these roads. I doubt those that would, would do so at 40kmph on a standard car, much less on a bike (which I don't think would capture these situations). You may wish to consider people's opinions on this thread too: https://lists.openstreetmap.org/pipermail/tagging/2014-March/016977.html On Fri, Mar 21, 2014 at 3:29 PM, Paul Johnson ba...@ursamundi.org wrote: On Fri, Mar 21, 2014 at 11:24 AM, André Pirard a.pirard.pa...@gmail.com wrote: The problem comes with such roads as Belgian N674 which is uniformly classified as national on IGN official maps. On the eastern part, it's worth the primary status for through, heavy traffic. On the center part, it's certainly only secondary. But on the part going NW it's a dangerous road. And, despite its official status, only its 5 m width and bends can show that : 2.5 m wide lorries can't cross each other and they step on the verge. The road once crumbled down into the meadow below and is waiting for the next turn. Even cars must break and make a brisk turn. It would be nice that OSM routing avoided that road. Sounds like a reasonably well equipped routing engine would naturally avoid it if there's a better alternate available just based on the number and radius of curves, classification of the roadway, surface type, and the vehicle being driven. Bonus if horizontal and vertical limitations of the roadway are mapped and the routing engine is aware of the x, y and z dimensions of the vehicle in question (which is why I see a lot of driverless vehicle technology being more practical for navigation assistance for human drivers than as a fully autonomous vehicle). Of course everybody is free to add a road width as well, there is the tag width for this, and also the tag lanes. Unfortunately until now, only 5% of all highway-elements (admittedly not only roads) have the tag lanes and 1% has the tag width. The width would come as a complementary information: avoid it despite a gentle official classification apparency. Does anyplace outside North America subjectively tag highway=* or is it formally tied to the official classification in most places, such as it is in the UK? Moreover, the width can be very easily measured with JOSM on Bing. you should be careful with the spherical mercator projection though, you might end up with different widths for the same width due to different latitudes, I am not sure how precise those measurements in JOSM actually are (some time ago they weren't but maybe this is fixed now). Good point that would have to be analyzed. Especially if there's a difference between NS and EW measurements! I would also be interested in hearing if the JOSM measurement tools are currently maintained to be accurate. Granted, I'm not expecting it to be as accurate as finding some survey marks on either verge and start running survey lines (for a couple reasons, 1) A digital theodolite, it's accessories, getting licensed as a traffic control engineer, filing permits and putting out traffic control devices to do so safely and accurately is probably beyond the reach of almost everyone here besides the parallel universe me that won the Powerball jackpot and now has nothing better to do; and 2) most available aerial imagery, when properly aligned, seems to be getting us a horizontal dilution of precision within the resolution of the imagery or better on objects created by relatively skilled and experienced mappers (based on triangulation from known survey markers to known points and lines when I've had the access to professional surveying equipment). Of course, the closely related parameter is speed. related to width? I do not think there is a close relation, at least not a reliable one. Speed (to drive safely) is not intrinsic but in fact a consequence of other factors, including narrow width. Or it can be enforced. In some places, quite strictly. Oklahoma will write you up for 76 in a 75 maxspeed or 39 in a 40 minspeed.
Re: [Tagging] Opinion on meaning of tracktype, smoothness and surface for routing
On Fri, 2014-03-21 at 13:29 -0500, Paul Johnson wrote: Does anyplace outside North America subjectively tag highway=* or is it formally tied to the official classification in most places, such as it is in the UK? In the UK, tertiary/unclassified/residential is subjective, other roads are tagged according to their official classification. In terms of routing in the UK, smoothness is not so much of an issue. The major factors are width (whether 2 vehicles can pass without slowing down), twistiness and visibility (the two go together, we have a lot of hedges which reduce forward visibility). Phil (trigpoint) ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Opinion on meaning of tracktype, smoothness and surface for routing
Brazil has no official system of classification (there is an administrative classification, which the Brazilian community found useless to determine the way's importance), so we've come up with this general recommendation (which may not be followed closely, in which case the mapper should add a note explaining why): http://i.imgur.com/YH8azIA.png Visibility is an interesting criteria, do you take it into account when deciding classification? Do you tag it? On Fri, Mar 21, 2014 at 4:41 PM, Philip Barnes p...@trigpoint.me.uk wrote: On Fri, 2014-03-21 at 13:29 -0500, Paul Johnson wrote: Does anyplace outside North America subjectively tag highway=* or is it formally tied to the official classification in most places, such as it is in the UK? In the UK, tertiary/unclassified/residential is subjective, other roads are tagged according to their official classification. In terms of routing in the UK, smoothness is not so much of an issue. The major factors are width (whether 2 vehicles can pass without slowing down), twistiness and visibility (the two go together, we have a lot of hedges which reduce forward visibility). Phil (trigpoint) ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging -- Fernando Trebien +55 (51) 9962-5409 The speed of computer chips doubles every 18 months. (Moore's law) The speed of software halves every 18 months. (Gates' law) ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Opinion on meaning of tracktype, smoothness and surface for routing
On Fri, 2014-03-21 at 17:15 -0300, Fernando Trebien wrote: Brazil has no official system of classification (there is an administrative classification, which the Brazilian community found useless to determine the way's importance), so we've come up with this general recommendation (which may not be followed closely, in which case the mapper should add a note explaining why): http://i.imgur.com/YH8azIA.png Visibility is an interesting criteria, do you take it into account when deciding classification? Do you tag it? We don't tag is specifically, but it is part of the mental tertiary/unclassified decision process. As hedges are mapped more, maybe that is an additional factor routers will be able to use. Phil (trigpoint) On Fri, Mar 21, 2014 at 4:41 PM, Philip Barnes p...@trigpoint.me.uk wrote: On Fri, 2014-03-21 at 13:29 -0500, Paul Johnson wrote: Does anyplace outside North America subjectively tag highway=* or is it formally tied to the official classification in most places, such as it is in the UK? In the UK, tertiary/unclassified/residential is subjective, other roads are tagged according to their official classification. In terms of routing in the UK, smoothness is not so much of an issue. The major factors are width (whether 2 vehicles can pass without slowing down), twistiness and visibility (the two go together, we have a lot of hedges which reduce forward visibility). Phil (trigpoint) ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Opinion on meaning of tracktype, smoothness and surface for routing
On 2014-03-16 22:37, Fernando Trebien wrote : Hello, Following from this conclusion (https://lists.openstreetmap.org/pipermail/tagging/2014-March/016904.html), I'm now trying to find a way to use tracktype, smoothness and surface to improve routing quality. For an average 4 passenger car (not an SUV, not a truck, not a motorcycle), I believe that: 1. Maximum "safe speed" is limited by how regular the surface is and also by how dense the surface material is. The exact material (in the "surface" tag) is not so important for routing as are these other two qualities (smoothness and material density). 2. Smoothness and surface density could be somewhat guessed from "surface" tag in most cases, and smoothness and tracktype could refine this guess. ... Following a gentle dispute on OSM-talk-be about the class of a particular road, I pointed out without any follow-up that road classification (primary ... tertiary, as well as national ... local on IGN maps) is very subjective but that the road width is very objective. Moreover, the width can be very easily measured with JOSM on Bing. Of course, the closely related parameter is speed. Two other optimizing data for routing appear to be readily available: declivity as contour lines and straightness which is computable from the map of the road. I think that the only left parameter (beside varying weather, of course) is what you deal with: surface. Not only "will the car be hopping?" but also "is it slippery?", the latter only as a local condition. If we could find an indisputable value for road surface, we could build a very valuable routing database, probably innovative but unfortunately easy to steal. But could we find an objective measure of the surface? That is, such that everyone comes the the same value, not subjective. While reading your texts, I've had a crazy idea: measuring vibration in the car. There are Android vibration measuring programs like Vibration Monitoring. Alas, car vibration is very much dependent on car suspension. But would some of us experiment this or another idea and come up with a solution? Wouldn't it be great to organize a well thought out worldwide road quality tagging party? Sadly, traffic restriction tagging is in a miserable state. People even laugh at me, and that is at themselves, when I talk of GPS. More of this later, I hope. Cheers, André. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Opinion on meaning of tracktype, smoothness and surface for routing
2014-03-20 15:02 GMT+01:00 André Pirard a.pirard.pa...@gmail.com: Following a gentle dispute on OSM-talk-be about the class of a particular road, I pointed out without any follow-up that road classification (primary ... tertiary, as well as national ... local on IGN maps) is very subjective but that the road width is very objective. yes, the highway classification is slightly subjective but as osm shows, the cloud can usually find a commonly accepted values, so this doesn't seem to be a real problem (also because it doesn't really matter if a road is classified as secondary rather than primary, and more than one class up or down is usually not the range up to discussion). Of course everybody is free to add a road width as well, there is the tag width for this, and also the tag lanes. Unfortunately until now, only 5% of all highway-elements (admittedly not only roads) have the tag lanes and 1% has the tag width. Moreover, the width can be very easily measured with JOSM on Bing. you should be careful with the spherical mercator projection though, you might end up with different widths for the same width due to different latitudes, I am not sure how precise those measurements in JOSM actually are (some time ago they weren't but maybe this is fixed now). Of course, the closely related parameter is speed. related to width? I do not think there is a close relation, at least not a reliable one. While reading your texts, I've had a crazy idea: measuring vibration in the car. There are Android vibration measuring programs like Vibration Monitoring. Alas, car vibration is very much dependent on car suspension. But would some of us experiment this or another idea and come up with a solution? this sounds interesting indeed, while I agree that it mostly depends on the car suspension. With (unsuspended) bicycles this would be more reliable I guess, but still the ability of the driver / rider to avoid holes in the surface might make a huge difference (e.g. in Rome there are some very bad roads with profund holes that get tapped every now and then but later reopen due to the heavy traffic. If you are on roads that you drive often you almost automatically get the habit of avoiding them, also at higher speeds, because you know their exact locations by mind). cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Opinion on meaning of tracktype, smoothness and surface for routing
Even so, we would still have to presume things about the driver's personality (an adventurous person would not care much about rougher surfaces, while a precaucious one would probably rather avoid them). We can pick a standard personality (we don't even know that very well without some statistics, do we?) or we can probe other people and then apply statistics on the results. Do you think my subjective sense is too off centre? Maybe you could provide speeds you think will be acceptable by most people and we can then compare and see how many people agree with each proposal, or disagree. If we get no further opinions, at least we can start with the average of our values, which is better than having them come from a single person whose experience may be distorted in some specific situations. On Thu, Mar 20, 2014 at 11:29 AM, Martin Koppenhoefer dieterdre...@gmail.com wrote: 2014-03-20 15:02 GMT+01:00 André Pirard a.pirard.pa...@gmail.com: Following a gentle dispute on OSM-talk-be about the class of a particular road, I pointed out without any follow-up that road classification (primary ... tertiary, as well as national ... local on IGN maps) is very subjective but that the road width is very objective. yes, the highway classification is slightly subjective but as osm shows, the cloud can usually find a commonly accepted values, so this doesn't seem to be a real problem (also because it doesn't really matter if a road is classified as secondary rather than primary, and more than one class up or down is usually not the range up to discussion). Of course everybody is free to add a road width as well, there is the tag width for this, and also the tag lanes. Unfortunately until now, only 5% of all highway-elements (admittedly not only roads) have the tag lanes and 1% has the tag width. Moreover, the width can be very easily measured with JOSM on Bing. you should be careful with the spherical mercator projection though, you might end up with different widths for the same width due to different latitudes, I am not sure how precise those measurements in JOSM actually are (some time ago they weren't but maybe this is fixed now). Of course, the closely related parameter is speed. related to width? I do not think there is a close relation, at least not a reliable one. While reading your texts, I've had a crazy idea: measuring vibration in the car. There are Android vibration measuring programs like Vibration Monitoring. Alas, car vibration is very much dependent on car suspension. But would some of us experiment this or another idea and come up with a solution? this sounds interesting indeed, while I agree that it mostly depends on the car suspension. With (unsuspended) bicycles this would be more reliable I guess, but still the ability of the driver / rider to avoid holes in the surface might make a huge difference (e.g. in Rome there are some very bad roads with profund holes that get tapped every now and then but later reopen due to the heavy traffic. If you are on roads that you drive often you almost automatically get the habit of avoiding them, also at higher speeds, because you know their exact locations by mind). cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging -- Fernando Trebien +55 (51) 9962-5409 The speed of computer chips doubles every 18 months. (Moore's law) The speed of software halves every 18 months. (Gates' law) ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Opinion on meaning of tracktype, smoothness and surface for routing
On Thu, 2014-03-20 at 15:02 +0100, André Pirard wrote: Following a gentle dispute on OSM-talk-be about the class of a particular road, I pointed out without any follow-up that road classification (primary ... tertiary, as well as national ... local on IGN maps) is very subjective but that the road width is very objective. Moreover, the width can be very easily measured with JOSM on Bing. Andre, I guess we can measure the width of a road to a reasonable accuracy via sat images. But I am not sure what that tells us. We cannot assume a relationship between width and quality of the road can we ? Not here in Australia anyway, many of the outback roads that are typical of the subject of this discussion are quite wide, wider than some of our fancy freeways closer to population centers. If we wanted to measure vibration I guess we could have a process to calibrate individual car's suspension. Maybe something like driving over a set of steel pipes of defined size a defined distance apart ? However, I doubt if we'd achieve anything useful, the sort of roads we are talking about are usually quite erratic, smooth sections then substantial holes or what ever. You slow down for the holes or you break something ! But interesting idea David Of course, the closely related parameter is speed. Two other optimizing data for routing appear to be readily available: declivity as contour lines and straightness which is computable from the map of the road. I think that the only left parameter (beside varying weather, of course) is what you deal with: surface. Not only will the car be hopping? but also is it slippery?, the latter only as a local condition. If we could find an indisputable value for road surface, we could build a very valuable routing database, probably innovative but unfortunately easy to steal. But could we find an objective measure of the surface? That is, such that everyone comes the the same value, not subjective. While reading your texts, I've had a crazy idea: measuring vibration in the car. There are Android vibration measuring programs like Vibration Monitoring. Alas, car vibration is very much dependent on car suspension. But would some of us experiment this or another idea and come up with a solution? Wouldn't it be great to organize a well thought out worldwide road quality tagging party? Sadly, traffic restriction tagging is in a miserable state. People even laugh at me, and that is at themselves, when I talk of GPS. More of this later, I hope. Cheers, André. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Opinion on meaning of tracktype, smoothness and surface for routing
We can't assume a relationship with road quality but I think we can assume some approximate relationship with maximum safe speed. No matter how smooth and well maintained a narrow (say 3m wide) road is, you can't drive safely at 90kmph on it, specially if it has curves. On Thu, Mar 20, 2014 at 7:18 PM, David Bannon dban...@internode.on.net wrote: On Thu, 2014-03-20 at 15:02 +0100, André Pirard wrote: Following a gentle dispute on OSM-talk-be about the class of a particular road, I pointed out without any follow-up that road classification (primary ... tertiary, as well as national ... local on IGN maps) is very subjective but that the road width is very objective. Moreover, the width can be very easily measured with JOSM on Bing. Andre, I guess we can measure the width of a road to a reasonable accuracy via sat images. But I am not sure what that tells us. We cannot assume a relationship between width and quality of the road can we ? Not here in Australia anyway, many of the outback roads that are typical of the subject of this discussion are quite wide, wider than some of our fancy freeways closer to population centers. If we wanted to measure vibration I guess we could have a process to calibrate individual car's suspension. Maybe something like driving over a set of steel pipes of defined size a defined distance apart ? However, I doubt if we'd achieve anything useful, the sort of roads we are talking about are usually quite erratic, smooth sections then substantial holes or what ever. You slow down for the holes or you break something ! But interesting idea David Of course, the closely related parameter is speed. Two other optimizing data for routing appear to be readily available: declivity as contour lines and straightness which is computable from the map of the road. I think that the only left parameter (beside varying weather, of course) is what you deal with: surface. Not only will the car be hopping? but also is it slippery?, the latter only as a local condition. If we could find an indisputable value for road surface, we could build a very valuable routing database, probably innovative but unfortunately easy to steal. But could we find an objective measure of the surface? That is, such that everyone comes the the same value, not subjective. While reading your texts, I've had a crazy idea: measuring vibration in the car. There are Android vibration measuring programs like Vibration Monitoring. Alas, car vibration is very much dependent on car suspension. But would some of us experiment this or another idea and come up with a solution? Wouldn't it be great to organize a well thought out worldwide road quality tagging party? Sadly, traffic restriction tagging is in a miserable state. People even laugh at me, and that is at themselves, when I talk of GPS. More of this later, I hope. Cheers, André. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging -- Fernando Trebien +55 (51) 9962-5409 The speed of computer chips doubles every 18 months. (Moore's law) The speed of software halves every 18 months. (Gates' law) ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
[Tagging] Opinion on meaning of tracktype, smoothness and surface for routing
Hello, Following from this conclusion (https://lists.openstreetmap.org/pipermail/tagging/2014-March/016904.html), I'm now trying to find a way to use tracktype, smoothness and surface to improve routing quality. For an average 4 passenger car (not an SUV, not a truck, not a motorcycle), I believe that: 1. Maximum safe speed is limited by how regular the surface is and also by how dense the surface material is. The exact material (in the surface tag) is not so important for routing as are these other two qualities (smoothness and material density). 2. Smoothness and surface density could be somewhat guessed from surface tag in most cases, and smoothness and tracktype could refine this guess. The exact safe speed for each value is probably a concern of each application, but for a guess of expected smoothness and expected tracktype (in the absence of these tags) in the absence of those tags, I need opinions. I think these associations make sense when the other tags are absent: [format: surface=smoothness,tracktype] asphalt=excellent,grade1 concrete=excellent,grade1 tartan=excellent,grade1 paved=good,grade1 paving_stones=good,grade1 concrete:plates=good,grade1 metal=good,grade1 compacted=intermediate,grade1 sett=intermediate,grade1 concrete:lanes=intermediate,grade1 bricks=intermediate,grade1 cement=intermediate,grade1 cobblestone=bad,grade1 wood=bad,grade1 stone=bad,grade1 rocky=bad,grade1 gravel=bad,grade2 fine_gravel=bad,grade2 grass_paver=intermediate,grade2 unpaved=bad,grade3 ground=bad,grade3 dirt=bad,grade3 grass=bad,grade3 pebblestone=bad,grade3 clay=bad,grade4 sand=bad,grade5 earth=bad,grade5 mud=very_bad,grade5 What do you think? I know each surface type can vary wildly, but I'm thinking of those situations in which people probably mean when they add a surface tag but not a smoothness or a tracktype tag. I'm not proposing these as defaults for tagging in OSM. I'm thinking about Emil Tin's idea (https://www.mail-archive.com/osrm-talk@openstreetmap.org/msg00389.html) of setting OSRM's speed according to surface as the minimum of several measures. I tried to multiply two factors as he suggests, but I was not satisfied with the resulting values. Then I tried to take the minimum of two speed values associated to smoothness and tracktype and it seemed much better. -- Fernando Trebien +55 (51) 9962-5409 The speed of computer chips doubles every 18 months. (Moore's law) The speed of software halves every 18 months. (Gates' law) ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
