[Tagging] Status of oneway=cw oneway=ccw

[Kevin Kenny]

On Tue, Mar 12, 2019 at 7:06 PM Volker Schmidt <voschix at gmail.com> wrote:
>
> Sorry, I am getting confused here (I am listening in as I frequently map bìcycle routes).
> The "oneway" tag  would only make sense on a loop-shaped route. And only if there are only ways and no nodes like signposts ecc, and if there are no branches, and only if all members of the route were oneway ways. Very special case.
> I normally handle oneway ways in a route which is bidirectional using the forward/backward roles on the ways concerned (as is also normal practice on bus routes around my part of the world). This is frequent for bicycles, but I would expect it to be very rare for pedestrians.
> If you want to indicate the preferred direction of a walking route that is basically loop-shaped, a concept that is different from the legally binding oneway, then some kind of clockwise / anticlockwise tagging should be used.
> If a hiking route contains parts which are oneway for pedestians then this should be tagged an all ways to which this applies with "oneway:foot=yes".

I'm confused, too.

There is one walking route local to me that is a circular route, about
11 km, through a small nature preserve.  It's certainly lawful to go
an any of the ways in either direction, and there are surely lots of
people in the preserve who aren't following the route but just taking
a different walk.  But the route itself goes only one way, because
it's not waymarked in the opposite direction.

In my notes, the plan is:

    (1) Put oneway=yes on the route relation, not on the ways.
    (2) Add the ways to the route relation in their proper sequence.
    (3) Give the ways the 'forward' or 'backward' role according to
the direction that the waymarked route follows.

There isn't any 'clockwise' or 'counterclockwise'; the relation reads
from start to end, and indicates which way it runs on each way it
visits. The fact that the end node is the same as the start node is
enough to make it circular.

Or rather, that *was* the plan.  I'm copying this from my notes, and
before I got around to revising the tagging, the trail maintainers put
up waymarks in the anti-clockwise direction, so I no longer had to
work through what to do about one-way marking.

This style of tagging (a one-way route overlaid on two-way ways, or
vice versa) would even allow for the situation where a hiking route
would have a section that walks on a roadway against the direction of
traffic (add oneway:foot=no to the way, but include oneway in the
relation if needed).  Long-distance routes in the US frequently
include short sections of road walk, to borrow a bridge, or to visit a
village where everyone on a route stops to resupply anyway, or simply
because no right-of-way has been secured for the trail or no trail has
yet been constructed, so it's pretty common to have route=hiking
overlaid on a small piece of road.

I don't know what a routing engine might do in the face of this, but
frankly, the whole idea of using a routing engine to choose among
hiking paths strikes me as a solution in search of a problem.

(Memo to self: come spring,
https://www.nynjtc.org/news/victory-long-path-schoharie-section-trail-permanently-protected
https://www.nynjtc.org/news/everyday-efforts-protect-and-improve-long-path
and several other relocations need mapping!)