The 86-year-old Cromwell woman, the driver and sole occupant of the Toyota Rav4, was "bruised and sore" after the crash on Saturday afternoon, but escaped serious injury, Senior Constable Brett Pay said.
She had been driving up the hill, travelling to Cromwell.
It appeared she had lost control of the vehicle which "flipped over" the safety barrier on State Highway 8, above Clyde, he said.
"The vehicle rolled several times before coming to rest against a tree about 30m down the bank."
The vehicle was extensively damaged and traffic was confined to one lane for several hours as emergency services secured the vehicle to stop it falling any further down the bank, and then took the woman out.
"They were able to get the woman out relatively easily but it was a more complicated exercise to retrieve the vehicle from where it was resting," Constable Rhys Tait, of Alexandra, said yesterday.
A hiab crane was used to drag the wrecked vehicle up the bank.
"She was a very lucky woman ... and I think her seat belt probably saved her life," Const Tait said.
"It was 30m - a fair way down a steep bank and I don't know how many times her vehicle rolled."
"There are quite a few trees where her vehicle went over the bank, but there's some bare patches along that bank too, so in some ways, it was fortunate the trees were there, to stop the vehicle rolling further."
The woman, whose name has not been released by police, was taken to Dunstan Hospital and would remain there for several days, under observation.
"I've talked to her today [Sunday] and she's pretty good, apart from some bumps and bruises and abrasions," Const Tait said.
Police want to hear from any witnesses.
