One of the longest trips in the North Island, 42 Traverse is open from December 1st till the end of April and takes you through some epic Central Plateau scenery. Recent work by DOC and the 4WD clubs have improved the conditions of the track and made it more accessible to more people.
Conditions vary considerably over the seasons - in the middle of summer it's a fairly simple drive, especially if it's been graded. Closer to Easter, it'll start getting wetter and may be more of a challenge.
Remember there will be other traffic and that it's a popular mountain bike track, so expect people.
Best not tackled alone due to the remoteness.