Emergency services were called to two separate crashes involving single cars hitting power poles on State Highway 2 between Masterton and Carterton on the weekend.
The first crash happened around 3pm on Saturday.
A Toyota hatchback was travelling north along State Highway 2 when it veered across the road.
The car hit a ditch, rolled and went through a fence, according to a police spokesman.
He said it appeared the driver might have suffered from a medical condition, and sustained minor injuries in the crash.
Masterton Fire Service station officer Kevin Smith said bystanders had helped people from the car before emergency services arrived, putting themselves at risk because of the downed powerlines.
"What they did was quite dangerous to themselves and others ... we had to treat the wires as live."
The fire service had diverted traffic down East Taratahi Rd and through a gate into the paddock, to avoid a fence which could have also been live, and gloves had been used to open gates, Mr Smith said.
In the second crash, a driver heading north on Sunday morning had been travelling north out of Carterton at the town boundary about mid-morning when his car veered left off the road and into a power pole.
Senior Constable Pete Cunningham said the driver, a man about 60, might also have been suffering from a medical condition that caused him to leave the road. He was taken to Wairarapa Hospital with suspected chest injuries.
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