A police spokeswoman said the truck and trailer unit had rolled at 4.30am and had ended up on its side, blocking half the road.
Nobody was injured.
At the moment traffic was filing past the crash.
A crane to get the smashed truck off the road was heading to the Ruapehu district to start the recovery effort. Police said that process was expected to take some time.
The Taupo District Council warned the road was likely to be closed until 5.30pm and advised motorists to use the diversion on the western side of Lake Taupo.
Police thanked motorists in advance for their patience.