The reason for a lateral offset is to avoid flying directly over traffic coming the other way.
One way routes do NOT have traffic coming the other way. The clue is in the name.
Therefore lateral offset on one way routes does not enhance separation, and may in fact reduce it.
So NB, you are confident (I'm not) that 2 aircraft on the same
one way airway, maintaining the centerline couldn't possibly come into close proximity, i.e. one cleared through the others level......
Couldn't possibly happen right? I get the point BTW, but at the pointy end..I see more and more holes lining up in Oz airspace.
If we discount the possibility because we assume procedures and implementation are robust, then we have the potential to miss the last step that could prevent an incident/accident.
Im not saying an offset is a panacea, but it does add another layer..we do it all the time through far busier airspace on one-way airways in other parts of the world as a matter of course and common sense.