He pulled into the right-hand lane and braked in an attempt to avoid a collision, but hit the car at 69km/h.
The vehicle went over the raised centre island, before coming to rest on the grass verge 38m away.
The 83-year-old driver was flown to Dunedin Hospital where he stayed in the ICU for two weeks before being transferred to the recovery unit.
He suffered an intra-abdominal bleed, a broken hip and a stroke, while his wife had injuries to her neck, back and hip.
“I had to learn how to walk again ... I could not eat or drink without assistance,” the man said.
“The way that I intended to live out the rest of my life has been taken away from me, and that is a hard pill to swallow.”
The court heard the couple could no longer live in their house and had to move into a rest home to receive assistance after the crash.
Judge Catriona Doyle accepted Aitcheson-Marwick was “extremely remorseful” and had taken responsibility for the incident.
She said the offending had “life-altering permanent consequences for the people who are the victim of your dangerous driving”.
Judge Doyle sentenced the Aitcheson-Marwick to four months’ community detention and ordered him to pay $2000 reparation to each victim.
“This is going to sound like a light sentence for the victims in this matter who now have their own life sentence,” she said.
She disqualified Aitcheson-Marwick from driving for 12 months, which she said was a “significant penalty” for someone his age.
