"I was driving along slower than I usually drive, because the road was pretty wet. I saw the earth move in front of me, and the tree came crashing down."
She said the tree fell about 10m in front of her car, and she slammed on her brakes and stopped just in time.
Although she was in shock, her first thought was to warn other drivers, she said.
She said the road was fairly busy, and cars began to arrive within minutes, but she was able to wave and slow them down.
Fulton Hogan contractors had been working on flooding further up the road, and arrived to help within minutes.
Ms Hollander said she was left feeling shaken but very lucky - and despite her raincoat and gumboots, very wet.
"I'll be in front of the fire at home for the rest of the day."