In October 2006, the NZ Transport Agency Board (then Transit NZ) approved the passing and overtaking policy for New Zealand's rural two-lane state highways with speed limits of 80km/h or more and up to the point that four-laning is likely to be required.
Two-lane rural state highways typically run through rural and peripheral urban land-use areas. They make up about 90% of New Zealand's state highway network and carry about 30% of New Zealand's annual road travel (as measured in vehicle kilometres travelled).
Read about passing and overtaking in appendix 3E of the Planning policy manual