"State Highway 29 is a treacherous stretch of road but I'm quite sure I fell asleep," Mrs Murray-Benge said.
"I remember driving past Mills Reef thinking I should pull over and take a break because I was so tired but I thought, 'No Margaret, keep going you're nearly home' and I think I fell asleep."
The 69-year-old suffered moderate injuries but walked away from the accident, which happened on SH29, metres from the Belk Rd intersection.
Her car hit a power pole and flipped on to its roof. Mrs Murray-Benge was trapped inside the car for about 20 minutes before emergency services arrived.
"It felt like an eternity but they were there very quickly," Mrs Murray-Benge said.
"I couldn't move, I could only move my right hand and I tried to turn the car off but it wouldn't go off.
"Lower Kaimai resident Terri Gregory [was] at my window and she told me, 'Margaret don't move, don't worry I've called the services, they're on their way'."
Mrs Murray-Benge said she was exhausted. "There's so much going on in my life, it's been a very tough time."
Mrs Murray-Benge spent Tuesday night in hospital before she was discharged yesterday morning and was still recovering today.
In February, Mrs Murray-Benge welcomed news that the New Zealand Transport Agency (NZTA) had approved $300,000 funding for a proposed safety upgrade for SH29, near Soldiers Rd, on the Kaimai Range.
She said at the time there had been some "barbaric" crashes in the stretch over the years.
"Too many people have died in this area and I've been waiting for this for a long time," she told the Bay of Plenty Times in February.
"I think people have to drive to the conditions and take care, but this area has long been in desperate need of an upgrade."