Talk:Accepted features/Smoothness: Difference between revisions

From OpenStreetMap Wiki
Jump to navigation Jump to search
Line 100: Line 100:
:* More important, we get into conflict with other tags. Many people might imply that they can use a way with "Usability=sport_car" with their sports car, although it might be a road without car access ("access=no"). It would also be very strange to tag a 50cm wide path in the alps with "usability=4wd" (although it definitely can't be used by a 4wd), only because I want to make clear that I can use it with a mountain bike. -[[User:Chrischan|Chrischan]] 20:29, 8 July 2008 (UTC)
:* More important, we get into conflict with other tags. Many people might imply that they can use a way with "Usability=sport_car" with their sports car, although it might be a road without car access ("access=no"). It would also be very strange to tag a 50cm wide path in the alps with "usability=4wd" (although it definitely can't be used by a 4wd), only because I want to make clear that I can use it with a mountain bike. -[[User:Chrischan|Chrischan]] 20:29, 8 July 2008 (UTC)
:: The 50cm 4WD path is a point well taken. Unfortunately, you can also turn this argument against your original proposal. How do you tag a 2,50m wide track which has two very smooth drive traces but requires HC because the cross cut profile of the track looks like this: __x^x__ (smooth traces left and right but a something in the middle that would cause every passenger car to hit the ground)? I'm lacking the proper English terms for this but such tracks are not uncommon. If you tag it with smoothness=bad people driving in cars will know they can't use it but people riding city bikes will assume they can't use it either, although they actually might be well able to do so. To me it looks as if usability by bikes and cars (not to speak about other types of vehicles) might actually require different scales. :-/ [[User:Ukuester|Ukuester]] 08:20, 9 July 2008 (UTC)
:: The 50cm 4WD path is a point well taken. Unfortunately, you can also turn this argument against your original proposal. How do you tag a 2,50m wide track which has two very smooth drive traces but requires HC because the cross cut profile of the track looks like this: __x^x__ (smooth traces left and right but a something in the middle that would cause every passenger car to hit the ground)? I'm lacking the proper English terms for this but such tracks are not uncommon. If you tag it with smoothness=bad people driving in cars will know they can't use it but people riding city bikes will assume they can't use it either, although they actually might be well able to do so. To me it looks as if usability by bikes and cars (not to speak about other types of vehicles) might actually require different scales. :-/ [[User:Ukuester|Ukuester]] 08:20, 9 July 2008 (UTC)

== Don't try to fit the surface description into one key, use more objective tags ==

I don't think this tag alone describe the surface better than the other tags for surface and tracktype.
This may fit for wheeled vehicles somehow, but why use the subjective keys and don't use directly the size of wheels that works on this surface?

I suggest to use a combination of tags to describe the surface. Some of the tag may even be subjective. The usability tag above is a start. We may extend the surface tag from paved/unpaved to describe better if it's sand, asphalt, concrete, stone, grass.
* example: An old shabby residential road
highway=residential, width=5, surface=asphalt, smoothness=coarse, usability=bike, clefts=yes, minwheelsize=25cm
* example: A narrow track with paved surface in good condition
highway=track, width=3, surface=paved, smoothness=fine, usability=roller, clefts=no, minwheelsize=5cm
Of course you don't need all those tags for each road. You can assume some defaults. The last example don't need the usability tag, it should be clear from other tags that the surface is usable for skates --[[User:Ast|Andy]] 14:20, 9 July 2008 (UTC)

Revision as of 14:20, 9 July 2008

Ok, I agree with the smoothness tag as proposed in you'r tab, because I need something like that for mountain track roads ( saying which vehicule you need at least to drive on it ) Sletuffe 16:28, 16 May 2008 (UTC)

Even being new at OSM: from my view as a biker and inline-skater smoothness is a very practical solution in conjuntion with surface Pmurk65 27 May 2008

smoothness and surface

I dislike the dependencies between the proposed smoothness and the surface key. If I read your list correctly, a way with surface=cobblestone and smoothness=bad is illegal? I'd certainly like to distinguish between various grades of cobblestoned road. In my opinion, smoothness without surface is pointless, hence I'd rather a smoothness key refined surface, so you get excellent or good or intermediate paved roads, good to catastrophic cobblestoned roads, etc. So how about a key smoothness=0 (default), +1, -1 to refine a base smoothness for the type of surface? Robx 07:11, 30 May 2008 (UTC)

This dependency was not my intention. The surface descriptions in the second column are EXAMPLES, not used for definition. The smoothness of a way should be assessed solely based on the usability of that way by the vehicles I mention, NOT based on the surface. This is my whole point: as a user of a certain road or path I am only interested wether I can drive on this road or not. If I sit on a racing bike, I am not interested wether the surface of a way is cobblestone or mud, just wether it is smooth enough to be used with a racing bike or not. I changed the proposal to make that clear (hopefully). With your proposal of a refined surface key, it gets very difficult to draw usage-specific maps (e.g. for racing bikes), since there is a potentially infinite number of surface values. Imagine a piste on a salt lake -- with the surface key it would read "surface=salt", which would have no meaning before the key is integrated into all the renderers and Garmin type files and whatever. With "smoothness=excellent", it would instantly show up everywhere as usable with a racing bike, which is my intention. --Chrischan 11:05, 1 June 2008 (UTC)
I'm beginning to like the proposal. It doesn't store all relevant information, but it's a good start, and appears to be clearly defined. I've started tagging some roads around here, the better cobblestoned roads with smoothness=intermediate and the awful ones with smoothness=bad. Also some really smooth paved roads with smoothness=excellent. I'd suggest adding some default values: A road should have a default of smoothness=good given its surface is paved or unspecified. A road with surface=cobblestone should default to smoothness=intermediate. A track should probably default to intermediate also. Robx 20:09, 2 June 2008 (UTC)
Perhaps an additional value of "unknown" would be best as a default? I've even been on an interstate highway (motorway) which is definitely smoothness=bad, or maybe smoothness=intermediate if you're feeling generous. Just anecdotal, but I think it's a bad idea to imply the smoothness based on the highway (or even surface) classification. --Hawke 21:26, 2 June 2008 (UTC)
I'm sure those exist, but they're certainly the exception. A default of unkown (or rather, no default), includes in the smoothness tag also the information whether the way has been surveyed for smoothness, which may be a good idea. But I'd rather not add thousands of smoothness=good tags and rather state somewhere that I've surveyed a given area for smoothness. Robx 18:37, 8 June 2008 (UTC)

Subjective

I've never like subjective tags such as this. This is why tracktype=* never got anywhere, as it is not obvious what the difference between "bad" and "intermediate" is. For instance, the roads where I live are terrible, but saying as they're all like that, should it be smoothness=bad or smoothness=intermediate? Bruce89 14:19, 30 May 2008 (UTC)

I like it, as long as there are usable guidelines for how to tag. "suitable for roller skates" and "suitable for mountain bikes and 4-wheel-drive automobiles" is quite good, IMO. --Hawke 15:16, 30 May 2008 (UTC)
In my opinion, tracktype=* never got anywhere because it does not describe a singular property of a way, but a combination of properties. Smoothness, although as far as I know not being a standardized physical property, could even be measured physically (I think of a wheel of defined size, measuring the vertical deflection while being dragged along the way). Obviously, this would be very unpractical. But when you honestly try to classify the roads you know into that scheme (based on wether you would drive on it with the vehicles I mention), you will see that the classification is pretty unambiguous in *most* cases. But I think this is very similar to the width of a road: although it is a physical property, few people would actually bring a rule and measure the width, most people would guess. Still it is very good to know wether the width is 2m or 20m, or wether the smoothness is excellent or horrible. --Chrischan 11:36, 1 June 2008 (UTC)

Catastrophic?

I have to say that I'm not so sure about "catastrophic" for the lowest value, it doesn't seem to fit with the others. I suggest "horrible" as an alternative. I'd support the proposal though. --Hawke 15:20, 30 May 2008 (UTC)

I know what it means, I just don't think it's a very good word to use for a value here. --Hawke 17:06, 30 May 2008 (UTC)
Hawke, why do you think "catastrophic" does not fit with the others? I actually do not care about the values at all, I just want the schema ;-). But maybe I should add Alvs idea to have one more tag essentially saying "no wheeled access possible" beyond the 4wd access value. --Chrischan 11:42, 1 June 2008 (UTC)
It just doesn't fit with the rest, in my mind. "How was that sandwich you ate today?" "Oh, it was catastrophic!" doesn't work. Or -- "Hey, I want to go for a ride on Foo Lane; how's the surface quality?" "Oh, I wouldn't ride there, it's catastrophic!". "Catastrophic" to me would give a degree of badness to something that was already bad ("I had a catastrophic accident on my bicycle today").
I do like Alv's idea of a sixth grade beyond the 4wd level. Perhaps "impassable" would work, especially if this is intended to apply to wheeled vehicles only. Bipeds are quite good at navigating obstacles, and if it's impassable by them, we probably shouldn't be mapping it as any sort of routeable type.--Hawke 16:26, 2 June 2008 (UTC)
How about "very bad", then catastrophic as the lowest value. Otherwise it's too big a jump from grass to mountain tracks. --OliverLondon 16:28, 2 June 2008 (UTC)
I started mapping tracks as I was hiking this week end with the smoothness tag in addition of the highway=track tag, and it turns out that I mapped a lot of tracks with the lowest possible quality ( smoothness=catastrophic ). But I doubt any 4wd could pass the tracks I went to so I missused that tag because It lacks "above" (or below ;-) ) catastophic. So I wonder why those tracks were there If no 4 wheels vehicules can use them ? The answer to my question came 10 minutes later as we crossed their way : 2 differents 4 wheels vehicules, a tractor and a "Quad" ( in french ). So, I am in favour or adding a "horrible" or whatever we should call it level to increase to 6 the number of smoothness tags in the goal of mapping what can drive on after a 4wd. To my mind, Mountain Bike can drive where 4wd ( not the army ones) cannot, the "horrible" tag should fit for 4wd and the "catastrophic" tag for Mountain bike & Tractors & "quads" Sletuffe 13:34, 3 June 2008 (UTC)

impassable ?

ok this looks better because it's less subjective than catastophic, but I don't think it's ok either. Why ? Answer this : how could a track be impassable by 4 wheeled vehicules ? It cannot, by the fact that it was created as a track in the goal to make passing possible what's worse than horrible ? I'm not a native english speaker ? or could we insert a "very_bad" between bad and "horrible" ? Sletuffe 15:43, 4 June 2008 (UTC)

I think impassable wouldn't be applicable to tracks. On a footway, it would say that it wouldn't be passable by mountainbike. It's not a value that would be used much, mostly there for completeness. Robx

Laterally varying smoothness

In fact, it doesn't need to be specified. The proposal is quite usable the way it is right now. I'd suggest voting on this as is, and then considering refinements such as smoothness=bad plus smoothness:left_border=good plus left_border:surface=painted_paving_stones. If you encounter a way that doesn't quite fit, add a note or invent some appropriate tag. Robx 18:32, 8 June 2008 (UTC)

Vote? (and what about sand)

Since discussion seems to have died down without major objections, how about taking this to vote?

I did come across a minor problem: In the local forests, there's some deep sandy tracks (partly bridleways). Since they're barely passable by wheeled vehicles, I'd tag them smoothness=bad, but arguably they're really quite "smooth". Robx 07:42, 30 June 2008 (UTC)

  • Same as you, I'm using it for a while now, and would be sad to see it dropped ;-)
For your remark about "smooth sand" but passable ( only by 4wd ? then I would have tag it smoothness=horrible ), I forsee some confusion just because of the name "smoothness". If I understand this proposal correctly, and as I was saying here before Chrischan transformed it into a nice proposal, the real goal of it, as mentionned here in the proposal : The smoothness of a way should be assessed solely based on the usability of that way by the vehicles mentioned above, NOT based on the surface properties
In clear, even if it is a perfectly smooth surface such as a wall, because it isn't passable then it shouldn't be tagged with smoothness
Ok my example is bad because we don't tag walls, but I'm sure every one get the point Sletuffe

Accessibility / Usability?

I like the idea behind this proposal: "This is my whole point: as a user of a certain road or path I am only interested wether I can drive on this road or not." What I do not like are the names. If what you are after with with this tag is whether you can use a road with a particular type of vehicle and not how smooth the surface is (this is just a means to indicate whether you can use the road) than I think the name should be rather accessibility or usability. This is also why I proposed to extend the access tag to cover the semantics but it seems people prefer to reserve this tag for legal access restrictions. Something like accessibility=(car|hc|4wd|tractor) would work perfectly for motorized vehicles and is actually the way how it is done in most maps that I know. It has also the benefit of largely resolving the sand problem as well as the discussion about subjective scales (what precisely is the difference between bad and intermediate etc.). Above all the meaning will be clear for the users of the map (the meaning of accessability=HC is much more obvious than smoothness=intermediate). The only problem I see is that things like roller blades only interested in excellently smooth pavement will not be covered anymore. But such "vehicles" are really rather interested in the surface property and should be covered by the surface tag. Ukuester 15:58, 4 July 2008 (UTC)

I agree with you too, what we really need more than "is it made of grass, sand, cobblestone, stones, asphalt, smooth asphalt, asphalt ( that the surface tag can handle) is the usability of a way, and I feel that "smoothness" doesn't serve it well ( anyone comming very fast to this proposal would think it's intended for roller, skate or jogger ). Also I don't want to forget them, it's to my mind a secondary need.
You are saying it would bann "roller blades" why not ?, if I continue your idea, why not use accessibility=roller_blades ?
(by the way what is an HC ? )
I would prefer usability rather than accessibility, and would propose something like :
Proposal usable by minimum supposed surface
usability=roller roller blade/skate board and all below smooth asphalt or equivalent
usability=sport_car sport car/racing bike and all below asphalt or equivalent
usability=car city bike/normal car and all below none
usability=4wd 4wd and all below none
usability=tractor tractors/quads/tanks/mountain motorcycle/Mountain bike none
When reading my table, I might be agreeing with you that the 2 first might well be dropped and returned to the surface tag. But not sure because maybe someone will imagine a different surface type than asphalt where roller could still go.
The only thing I am not happy with in this table is the fact that the tag refers to one and only one vehicule while I'd like to refer to a "group of"
example, my "car" would better, but longer, be "any_vehicule_group_that_can_drive_where_a_car_can_drive"
Usability Usability ! that what counts.
using surface=asphalt and saying rollers can use it will fail when later someone add à surface tag that is different but still usable.
Is it easy to see that I hate the surface tag, don't use it, and don't understand the need for it ?
My point of vue might also be transposed to the way the access tag is used. We should think in terms of "group of vehicule sharing some properties" and "group of surface type sharing some properties" or else a routing program ( isn't it what we want in the end ? ) is unable to take into account all tags and variation that are added all the time to those tags.
HUGH !, this is the friday thought

Sletuffe 18:51, 4 July 2008 (UTC)

HC stands for "high clearance". For most tracks that a passenger car can not navigate you wouldn't need 4WD but simply a sufficient high clearance which some 2WD Jeeps have. The typical hierarchy for unpaved/dirt roads in the US (where this type of road is much more common than in Central Europe is "any passenger car can use" - "requires high clearance" - "requires four wheel drive" (example). I'm fine with using "usability" instead of "accessability" to make a more clear distinction to "access". I like your scale except that I would want to have hc added between car and 4wd. The fact that groups of vehicles are meant instead of particular vehicles should be made clear in the documentation of the tag. I would like to see a comment by Chrischan though. :-) Ukuester 11:58, 7 July 2008 (UTC)

This sounds like a totally separate proposal from Smoothness. You might want to create a new proposal and move this discussion over to it. --Hawke 16:38, 7 July 2008 (UTC)

I disagree. According to the proposal the rationale behind smoothness is "This is my whole point: as a user of a certain road or path I am only interested wether I can drive on this road or not." I tried to make this more explicit than it was in the original proposal. Please explain why you think that this is totally separate. Right now we have a proposal surface, another proposal additional surface values, a third proposal tracktype, and a fourth proposal smoothness which are all closely related. I don't think a fifth proposal usability will make thinks any better. Ukuester 07:34, 8 July 2008 (UTC)
I also think this discussion should stay here, because indeed it is what I intended with this proposal. Actually something like this was one of my first thoughts. But then I decided to propose it the way I did, because I think "smoothness" is exactly what I want to describe. With the tagging scheme above, I see two problems:
  • as mentioned above, I would like to address the "smoothness" independent of a particular type of vehicle. Ofcourse it could be mentioned in the documentation that a way for racing bikes should be tagged as "sport_car", but people only into biking would probably not start using this tag. Likewise, people driving in cars would probably not start tagging something as "roller_blade", because they think this is something for the roller blade crowd.
  • More important, we get into conflict with other tags. Many people might imply that they can use a way with "Usability=sport_car" with their sports car, although it might be a road without car access ("access=no"). It would also be very strange to tag a 50cm wide path in the alps with "usability=4wd" (although it definitely can't be used by a 4wd), only because I want to make clear that I can use it with a mountain bike. -Chrischan 20:29, 8 July 2008 (UTC)
The 50cm 4WD path is a point well taken. Unfortunately, you can also turn this argument against your original proposal. How do you tag a 2,50m wide track which has two very smooth drive traces but requires HC because the cross cut profile of the track looks like this: __x^x__ (smooth traces left and right but a something in the middle that would cause every passenger car to hit the ground)? I'm lacking the proper English terms for this but such tracks are not uncommon. If you tag it with smoothness=bad people driving in cars will know they can't use it but people riding city bikes will assume they can't use it either, although they actually might be well able to do so. To me it looks as if usability by bikes and cars (not to speak about other types of vehicles) might actually require different scales. :-/ Ukuester 08:20, 9 July 2008 (UTC)

Don't try to fit the surface description into one key, use more objective tags

I don't think this tag alone describe the surface better than the other tags for surface and tracktype. This may fit for wheeled vehicles somehow, but why use the subjective keys and don't use directly the size of wheels that works on this surface?

I suggest to use a combination of tags to describe the surface. Some of the tag may even be subjective. The usability tag above is a start. We may extend the surface tag from paved/unpaved to describe better if it's sand, asphalt, concrete, stone, grass.

  • example: An old shabby residential road
 highway=residential, width=5, surface=asphalt, smoothness=coarse, usability=bike, clefts=yes, minwheelsize=25cm
  • example: A narrow track with paved surface in good condition
 highway=track, width=3, surface=paved, smoothness=fine, usability=roller, clefts=no, minwheelsize=5cm

Of course you don't need all those tags for each road. You can assume some defaults. The last example don't need the usability tag, it should be clear from other tags that the surface is usable for skates --Andy 14:20, 9 July 2008 (UTC)