Mr Davidson came across the car while driving from Auckland to Palmerston North on a section of the Desert Rd known as "the wall".
He always keeps a special lookout in that particular stretch near Turangi - it's where Porirua truck driver Dave Budge died in 2012, and mesh has been put on the bank to form a wall. "There's usually a couple of crashes on the road every year and they are usually in the winter when the surface is slippery," Mr Davidson said.
The road was icy on June 1 last year when he found the stranded couple perilously close to the edge. "They were an Indian couple who looked to be in their 30s and I think they were headed for Auckland. I didn't talk to them much ... they were very shaken."
Last week he received the police Commander's Commendation Award , with Taupo area commander Inspector Steve Bullock saying: "Some people would have just driven past, but he stopped and assessed the situation and worked out what could be done. "He really deserves the award - stories like this inspire others to think that they too can make a difference."
Mr Davidson does not think his actions were heroic.
"I think if you see someone in trouble, you do what you can to help, it's that simple."
However, wife Rosie reckons she has a bit of a hero on her hands.
"He thinks anyone would have done what he did, but not sure everyone would or could.
"I'm very proud of him, and so is his mum."
Mr Davidson's mother, Carol de Vries, said her son didn't say much about the rescue at the time, but that doesn't surprise her.
"He doesn't make a fuss about things. I'm not surprised that he did this - it's just how he is and he's always been like that, always willing to help people just because it's the right thing to do."