On Mon, Aug 11, 2014 at 11:40:00PM -0400, Christopher Hoess wrote: > On Mon, Aug 11, 2014 at 5:33 PM, Richard Z. <ricoz....@gmail.com> wrote: > > > On Mon, Aug 11, 2014 at 12:28:59PM -0400, Christopher Hoess wrote: > > > > > > > Maintaining both "bridge=movable" and "bridge:movable=*" has at least one > > > useful side effect, which I documented, for bridge geeks like me (i.e., > > the > > > people who are probably going to be adding hyper-complicated bridge > > > detail); it lets you tag a formerly or planned movable span that is now > > > fixed in place with "bridge:movable=*" but not "bridge=movable". So you > > > could search for "bridge:movable=swing" and find both working and fixed > > > swing spans, but a router wouldn't treat the fixed ones as movable. (See > > > here http://en.wikipedia.org/wiki/1993_Big_Bayou_Canot_train_wreck for > > the > > > relevance of such spans.) > > > > This may be too subtle for many people and somewhat against the principle > > of least surprise. > > > > Good point. I can easily see people "correcting" "bridge=yes" to > "bridge=movable" because they see the bridge:movable tag on a span. What if > we made "bridge=fixed" a synonym of "bridge=yes"?
fine for me. > > > bridge=covered has been mentioned now and before as possibly redundant to > > > "bridge=yes" and "covered=yes". I left it in because of this message: > > > http://lists.openstreetmap.org/pipermail/tagging/2013-May/013546.html > > > <http://lists.openstreetmap.org/pipermail/tagging/2013-May/013546.html> > > which > > > suggested that a bridge covered over wasn't quite the same thing as a > > > covered bridge. I don't have a strong opinion on changing or keeping it > > at > > > this point. > > > > I would be in favor of keeping that one but the problem is - you can't have > > covered bridge=movable or aqueduct. I have seen covered aqueducts. > > > I don't think there are any extant covered movable bridges. Re. aqueducts, > in what sense was that "covered? A closed pipe? If we retain > "bridge=covered" in addition to "covered=yes", I think it should be > particular to the "classic" covered bridge where a truss (usually) has been > covered to keep out the weather. not a pipe, a classic viaduct with canal, a roof and arcade style half-open side walls. The purpose was not quite clear - not drinking water and other parts were not covered. Should we have bridge:cover ? > > > As long as we're simplifying possible values in bridge=, > > > "bridge=low_water_crossing", which is somewhat established but a bit > > > awkward, could theoretically just be marked by a separate tag, maybe > > > "flood_prone=yes". The essential quality we're looking to convey is that > > > the bridge is engineered to spend some time underwater and come out > > intact. > > > > those can also look as culverts and it would be nice to have the same > > solution > > whether it is a bridge or a culvert. I have tagged those with > > tunnel=culvert > > and ford=yes > > > "flood_prone" might be a little better for both in that I think of a ford > as having water more or less perennially covering the crossing, whereas a > low water bridge, like a road dipping into an arroyo, is only covered by > irregular intervals of high water. the flooding can be more or less frequent. In some places that I have seen the flooding was manmade und thus mostly predictable, bellow a dam. The difference I think is how it will be used for routing, so perhaps both are valid alternatives. Richard _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
