"This has had a profound effect on your lives and my heart goes out to each and every one of you," Thomas Kerr said in a statement to the Sydney Downing Centre District Court on Thursday.

"I will always be haunted and carry this burden with me for the rest of my life."

Kerr, 28, ran into the back of the group of cyclists in March last year as they rode along Southern Cross Drive in Eastlakes. All the riders were taken to hospital, suffering injuries ranging from abrasions to spinal fractures. One was facing years of rehabilitation after losing function in her right hand.

Three of the victims were present in court for the sentencing submissions. Kerr told them he could "partly relate" to their plight because he had suffered serious injuries while playing rugby league.

"I'm also searching for answers as to how exactly this happened," he said.

Kerr had not been drinking or speeding at the time of the accident and there was no suggestion he deliberately hit the group. Kerr previously told the court he had no memory of the crash.

His lawyer, Murugan Thangaraj, SC, said: "The only logical explanation for [the accident] must be momentary inattention or misjudgment."

Kerr's father, Barry, testified that the son he had taught to drive "wasn't a hoon".

But as Acting Judge Anthony Garling pointed out, Kerr's driving record did not help his case.

Between 2008 and 2010, Kerr was caught speeding twice, as well as driving while disqualified and driving while using a mobile phone. He also had a mid-range drink driving conviction.

Kerr pleaded guilty in December to four counts of dangerous driving occasioning grievous bodily harm and three counts of misconduct causing bodily harm.

He will be sentenced on Friday morning.