Huttite
Considering there is no consensus of a benchmark or standard mentioned for New Zealand on the wiki (see: http://wiki.openstreetmap.org/wiki/Tag:highway%3Dtrunk ), it is a bit hard to say yes or no. I notice that several other countries set the standard for a trunk road as a road designated as a national highway, regardless of build quality. Having recently driven this road, I would say it is a similar standard to some parts of SH1 in the Manawatu. i.e. Two lanes, white dotted centreline, gravel shoulders, big highway style green and white signage. And it is the primary route to Palmerston North from south of Levin - with clear roadside signage advising traffic of the turnoff. 