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
