In fact, the picture in this article does correspond to the description of grade4: "Almost always an unpaved track prominently with soil/sand/grass, but with some hard materials, or compressed materials mixed in."
Perhaps what people worry about here is "how soft" the surface is. There may be various degrees of "softness" to be measured. Could they be measured without too much hassle? The picture seems to give me a clue: the car is practically half-sunken in the ground. It kind of reminds me of how smoothness=very_bad is defined: high_clearance. However, the reason in the context of tracktype would be different: in smoothness, high clearance is required because of the shape of the surface. On tracktype, it would be required because the vehicle (heavy as it is and with wheels of some particular contact area) would otherwise sink that much into the ground. Lighter vehicles and those with larger wheels (larger contact areas) would be less likely to sink, even if smoothness is the same. At the same time, if you also think of surface shape, it's hard to argue it should be anything better than smoothness=very_horrible/specialized_off_road_wheels ("tractor, ATV, tanks, trial, Mountain bike and all kind of off-highway vehicles"). At least (subjectively) I wouldn't expect it to be passable by anything smaller than a tractor without imposing risks or severe difficulties. So, if applications used both tags as "limiting factors", the driver would stay safe as long as mappers applied both tags. Still, there may be situations with near perfect smoothness and almost no firmness/durability; an extreme situation would be quicksand. David, I tried to search for images of the "Kennedy Development Rd" in Queensland but none of the images I got would be tagged as tracktype=grade5. Do you have any example or any similar picture for what you've experienced? Or maybe a coordinate that we can have a peek at on Street View (either Google's or OpenStreetView)? On Thu, Mar 20, 2014 at 10:33 AM, Martin Koppenhoefer <dieterdre...@gmail.com> wrote: > > 2014-03-20 12:42 GMT+01:00 Richard Z. <ricoz....@gmail.com>: > >> That means that the description of grade5 in the wiki should be fixed as >> similar or worse than the road to Jakutsk: >> http://www.ssqq.com/ARCHIVE/vinlin27c.htm > > > > looking at those pictures it seems as if that's not even a track but a road. > If it were a track or if you were to apply tracktype anyway to this, I do > not see a reason why this cannot be e.g. grade4. It is obvious that bad > weather (rain, but also snow and ice) can make a road unpassable. > > 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