Contractors are about to start using dynamite to move thousands of tonnes of loose soil still threatening to come down on State Highway 11 near Kawakawa.
A huge slip has closed the highway at Lemon's Hill since February 13, forcing motorists travelling between Opua and Kawakawa to take the long way around via Pakaraka and Puketona.
NZ Transport Agency system manager Steve Mutton said there was still a significant amount of earth and rock sitting above the roadway, which would now be brought down the face of the slip using explosives. Blasting was due to start this week and would help get the road open as quickly as possible.
He expected traffic would be allowed through in two to three weeks time.
"Our crews are working as fast as safely possible, given the complexity of the slip, the difficult access and the weather interruptions. We're conscious of the importance of the link to the Bay of Islands for locals and tourists and we're working to reopen the road as soon as we can."