convert a set of ways to a GPX layer

[Jo]

When I'm converting route relations to v2, I started to remove all the
oneway streets from the route relations. This works well, as the routing
helper in PT_Assistant lets me reconstruct the itineraries quite easily.

For some routes however removing all the oneway streets, loses information
needed to reconstruct the routes, so now I was thinking to help the mapper
by creating a temporary layer with a GPX track in containing all the ways
that were in the route relation.

Is there a method I can call with an array / list of ways that can create
such a GPX layer?

Polyglot