One person has died in a crash near the Kaimai Summit.
State Highway 29 near the summit reopened just after 8.15pm after being closed for more than four hours.
Two others have been taken to Waikato Hospital in moderate conditions.
A police spokesman said emergency services were called to a crash between a motorbike and a car at 3.36pm.
The crash occurred between Hanga Rd and Rapurapa Rd.
Police say motorists should expect the road to be closed while responders attend the crash.
Fire and Emergency northern communications shift manager Paul Radden said two fire crews from Matamata were helping police at the scene.
A photographer at the scene earlier this afternoon said traffic from Tauranga was banked up to the Ruahihi power station and vehicles were being turned around.
The New Zealand Transport Agency has advised the detour for eastbound traffic is via SH28, SH5 and SH36. The westbound detour is SH36, SH5 and SH28.
A resident who lived near the Rapurapa Rd said she heard the sirens go by and believed the crash was on the Waikato side of the summit.
The road in that area was windy, she said.