I have said it before - and now I'll say it again;
In a modern Nav environment two way routes are a dangerous and stupid anachronism.
I takes only a little imagination to establish race tracks where possible - and where there isn't room for race tracks, formalise the strategic lateral offset.
The large navigation tolerances ATC apply to aircraft are largely fantasy in this day and age - if two are going to hit in the cruise, it will happen on track, not 14NM either side of it.