He said he did not see Mrs Smith on the pedestrian crossing, and believed his health could have affected his driving.
"I have regular diabetic, kidney and eye checkups, but have never thought to ask whether I should be driving. I realise now that it is a good idea to ask these questions about one's health," he said.
Mr Te Whata, a roofer, appeared in Dunedin District Court last week where he was disqualified from driving for six months and ordered to pay $2000 reparation.
He later told the Otago Daily Times the prospect of not being able to drive was daunting.
It was hard to give up something having done it every day for decades but being responsible for causing someone's injuries, and knowing the trauma, anxiety and financial cost of those injuries was worse.
"In the early days, not knowing whether they are going to survive is very scary and stressful. The police do not allow you to have contact with the victim of their family to say you are sorry or to ask how they are progressing," he said.
Mrs Smith spent 11 days in Dunedin Hospital, where she underwent a knee reconstruction, and almost six weeks in a rehabilitation unit.
She had a fractured skull and broken collar bone, as well as a badly damaged knee.
As a result of her skull fracture, just behind her right ear, she had a constant "screaming whistling" in that ear and had to listen to white noise to drown it out.
Her husband David said the entire family was affected by the incident; their children dropped work and family commitments and he retired early as a ship's captain.
"It caused turmoil," he said.
Mr and Mrs Smith believed there were many people either concerned about being fit to drive, or whether a relative or friend was.
It was a hard topic to broach, and they hoped their story would encourage more discussion about the risks and consequences of driving with a physical impairment.
"Hopefully this is a realistic way people can communicate their fears. If families have to resort to hiding keys and hiding cars then that's really stressful for them as well," she said.