The curtain-sided truck, without a trailer, was travelling towards Napier and crossed the road before crashing. It was described as a single-vehicle crash, but police inquiries were continuing.
Fire and Emergency NZ Napier senior station officer Ryan McCarty told Radio New Zealand the truck was held above the ravine by two large trees that snapped in the crash.
"So he was sort of hanging - the truck was wedged against one bank and the back side was overhanging the ravine," McCarty said. "The ravine was a quite a steep drop underneath, probably a good 30m. As far as extractions go it was probably about as hard as they come."
A "variety" of tools were used to cut the cab apart to remove the man from the wreckage after it was secured to a ground anchor on one side of a bank and to a tree to stop it falling any further, he told Hawke's Bay Today.
A motorist who arrived at the scene soon afterwards said it was about 30 minutes later that before emergency service crews arrived.
Conditions were wet and the motorist said "heavy and icy" rain started falling as the rescue began, and continued to "about halfway through" the rescue, McCarty said.
The man was ultimately lifted from the cab and placed on a board to be raised to the roadside.
Two cranes from Hawke's Bay arrived about 1.45pm to start the salvage, of what was one of many trucks to have come to grief on the notorious 130km stretch of highway, particularly in the area from Te Haroto to Te Pohue.
Truck driver and road-upgrade campaigner Antony Alexander, who would be travelling the highway again late on Sunday, said surface conditions on the highway have barely improved, but should not be attributed as "the" cause of the crashes.
But he believes the potholes, sometimes reappearing soon after work being done, could, along with other road conditions, be a factor in some of the driver behaviour involved in crashes.
Some drivers believe maintenance and upkeep have suffered as a result of the National Government's switching switching of focus about 10 years ago to "roads of national significance" (RoNS), concentrating mainly on highways and motorway systems near other major centres.
But Road Transport Forum spokesman Nick Leggett disagrees with the priorities, having inspected the road recently with Alexander and Hastings District mayor Sandra Hazlehurst and her deputy, Tania Kerr, a resident of the area.
He says in a Talking Point, published in today's Hawke's Bay Today: "This is a national issue, as that road connects the central North Island with the east coast and importantly, Napier Port. And it's deadly dangerous. It is, frankly, a national disgrace."
Police from both Hawke's Bay and the Bay of Plenty district, which includes Taupō, have recently met to consider aspects which may be able to be improved pending major maintenance or works.