On Sun, 2014-08-10 at 14:10 +0200, Richard Z. wrote: > On Sun, Aug 10, 2014 at 12:41:22PM +0200, Colin Smale wrote: > > On 2014-08-10 12:13, Никита wrote: > > > > >I.e they define this tag as subtype of > > >http://en.wikipedia.org/wiki/Arch_bridge [5]. I don't see any real > > >application/use to bridge=humpback. Also, bridge=humpback does not imply > > >covered=yes by default. It does not define routing aspects or adds any > > >features to end users. > > > > In the UK there are warning signs for some humpback bridges, and with good > > reason - if you don't slow down substantially from the ambient speed you > > will be launched into orbit. Therefore they should be useful for routers, > > implying a lower speed on that part of the road. > > > > https://uk.answers.yahoo.com/question/index?qid=20120222085933AAsnJiP > > > > Some are so "humpy" that a vehicle with a long gap between the axles and/or > > a low ground clearance (e.g. a low-loader) may actually be unable to cross > > the bridge. > > > > So I don't think it is right to say that bridge=humpback cannot be of value > > for routing or end users... > > that is true, but shouldn't the routing sw be able to evaluate > bridge:structure > and bridge:movable as well? > The intention was to add swinging rope bridges as a value of bridge:structure > and > those may be relevant for routing as well
A movable bridge is certainly something that can add a time penalty for routing, it is something that is probably not so easy to predict, most of the time there is no penalty but at times this could be quite significant, in the same way as a level-crossing, most of the time there is no delay but if you meet a train then it can be long. I guess routers could take account of the timetable, I certainly try to avoid the local crossing when a stopping train is due. I do not like the idea of bridge=movable. whilst true, it is only useful to routers and looses the diversity of OSM, we should not dumb-down tagging just because it is not universally understood Movable in itself could mean many things, lifting, swing or even transporter. The other speed penalty with humpback bridges is visibility, often more than walking pace can potentially result in a head on collision. 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
