Auckland-bound motorists can use State Highway 2. Waikato-bound motorists can use SH36 via Ngongotaha and SH5.
UPDATE 4.54pm: SH29 has been closed in both directions while the serious crash unit is in attendance, after one person died in a crash and another was injured.
Police have asked motorists to avoid the area.
4.05pm: Police have confirmed one person has died in a crash on SH29 on the Lower Kaimai Range, and another has been injured.