Re: NZ and territories
Yes, in NZ all lanes are legally equal, and in some way separate roads. It is regarded as polite for slow traffic to keep left, but I don't think it's enforceable.
I once got pinged for using a motorway onramp to overtake, there being three vehicles driving persistently side by side in the three lanes for some km. My offence, apparently, was changing lane from a proper motorway lane onto the onramp -- not the overtaking itself.