[Tagging] Reversible Road tagging

[Richard]

On Sun, Nov 11, 2018 at 07:59:41PM -0600, Paul Johnson wrote:
> lanes=* should be the total number of lanes... if it's a one-lane road with
> two way traffic, I'd go with...

things change somewhat when using lanes:forward:conditional and 
lanes:backward:conditional - these are not likely to sum up to
a constant total number of lanes.

But thinking more about it reversible freeways can definitely not 
be modeled using lanes alone. 
oneway:conditional and oneway=reversible would be the cleaner
solution.

> On Sun, Nov 11, 2018 at 4:01 PM Richard <ricoz.osm at gmail.com> wrote:
> 
> > On Sun, Nov 11, 2018 at 12:27:57AM -0600, Paul Johnson wrote:
> > > Are we talking a 1 lane or a 3 lane road?  Because that looks like it's
> > > describing a 3 lane road.
> >
> > looks like 1 lane to me but the example would not work for other reasons.
> >
> > We could do
> >
> > lanes=0
> >   # this is "default" for routers/apps which don't undrestand/use
> > conditional
> >   # restrictions
> > lanes:forward:conditional=2 @ (09:00-17:00)
> > lanes:backward:conditional=2 @ (17:01-8:59)
> >   # the version for apps which do understand them
> >
> > However, I am afraid that "lanes=0" won't stop most routers sending cars
> > that
> > way, other kind of restriction is needed here.
> >
> > That could be
> > access=no
> > access=yes @ (09:00-17:00); yes @ (17:01-8:59)
> >  # this two lines are needed to sort out routers/apps which don't
> >  # undrestand/use conditional
> > oneway:conditional= yes  @ (09:00-17:00); -1 @ (17:01-8:59)
> >
> > In principle
> > oneway=reversible
> > oneway:conditional= yes  @ (09:00-17:00); -1 @ (17:01-8:59)
> >
> > would be a much more elegant solution but again, I am afraid that
> > oneway=reversible isnt widespread enough to be known by most routers.
> >
> > I have just added that as hypothetical example to
> > https://wiki.openstreetmap.org/wiki/Tag:oneway%3Dreversible
> >
> > The lane number could be added on top of that  - and would be very
> > confusing if it were variable because there would be backward/forward
> > lanes on top of reversible oneway..

Richard