Police have named the man who died when his truck plunged down a steep slope on the Kaimai Ranges last night.
Acting sub-area manager for Matamata-Piako Sergeant Neil Faulkner said the driver was Athol Ian Bree, 61, of Te Awamutu.
Mr Bree died at the scene of the 6.25pm crash, which happened about 1km from the summit on State Highway 29.
One lane of the road will remain closed until about 4pm as crash investigators and salvage crews survey the scene and try to recover the truck and trailer unit.
"Traffic on this busy stretch of road has been reduced from three lanes down to one causing some delay,'' police said.
"A heavy recovery vehicle is currently in place and work is continuing on trying to recover the tractor and trailer unit while crash investigators continue to map out the scene.''
District Road Policing Manager, Inspector Leo Tooman, said a member of the public flagged down a Bay of Plenty Police officer near the summit of the Kaimais, to report a large amount of sand spilt over the road.
"The officer went to investigate and found that a truck and trailer unit had crashed through a barrier and dropped several metres down a steep bank."
Mr Tooman said investigations into what has occurred are being carried out by the Waikato Serious Crash and Commercial Investigation Units.
"Initial indications are that the truck and trailer unit was on the Waikato side of the ranges travelling downhill when the driver has lost control on a sharp bend about 1km from the summit.
"It looks like the trailer has rolled spilling its load of palm kernel across the road as it has slid across the two opposite lanes and crashed through the Armco barrier, dropping about 100m down the bank. The bin on the truck has sheared off and the tractor unit has then crashed through the barrier."
The tractor unit has come to a rest about 20m down the bank with the vehicle's cab being badly crushed, he said.
Mr Tooman said after a long spell of fine weather and a fatal free holiday weekend last night's crash was a tragic reminder how conditions can change without warning.
"SH29 is a very busy part of our roading network with greater than normal levels of heavy road transport heading to and from the Port of Tauranga. With trucks powering up the hill there is often a degree of diesel spillage which, when combined with wet weather, can make for a lethal combination.
- Herald Online and APNZ staff