[OSM-talk-be] walking route in one direction

[Ben Laenen]

Ivo De Broeck wrote:
> A lot of walking routes are only marked in one direction. Can you make the
> relation oneway??

With forward/backward roles on the members of the route relation.

On http://wiki.openstreetmap.org/wiki/Relation:route there's a small 
explanation:

"if a route should only be followed in one direction for some or all of its 
length, the "role" can indicate this for some or all of the constituent ways. 
"forward" means the route follows this way only in the direction of the way 
and "backward" means the route runs only against the direction of the way. 
Rendered on the cycle map (example 
http://www.openstreetmap.org/?lat=51.88888&lon=0.89395&zoom=17&layers=00B0FTF 
)."

In Potlatch you can edit the role in the lighter gray box next to the relation 
name at the bottom in the tag list. In JOSM it says more clearly in which 
column you can find the role (in the relation list of each member or in the 
member list of each relation).

So, if you have a route from A to B via C and D like this (the arrows are the 
way directions):

   A -----> B <------ C <----- D

Then the way AB will have role forward (because the direction of the route is 
the same as the way)
The way BC will have role backward (because it's the opposite direction)
CD has role backward for the same reason.


Suppose you have another route from D to A then the roles switch, so then AB 
becomes backward and BC and CD have role forward.

Ben