Validator doesn't allow for oneway (parts of) hiking and cycling routes

[cartinus]

The validator does not recognize the roles forward and backward for cycling and hiking routes. Also if the route is completely oneway it complains there are no ways with role <empty>.

For an example of a completely oneway hiking route, see ​relation 2910040

For an example of this problem with cycle routes, see ​this question on help.osm.org. This question also contains a probable solution to the problem.