A large truck rolled on State Highway 2, near Pukehina, earlier this morning, blocking both lanes of traffic.
Traffic diversions are in place around the crash 2km east of Pukehina and police said the truck was leaking fuel.
The driver was unharmed and emergency services were in attendance.
Traffic has been diverted while the trucks is being removed and the discharged fuel cleared from the road.
Removal and clean-up was expected to take at least a few hours, as a heavy lift crane was needed to remove the truck.