A Victorian truck driver responsible for killing a toddler in a multi-vehicle crash claims he was awake but distracted in the lead-up to the fatal collision.
Other motorists saw Matthew John Livingston, 44, swerving between lanes on the Calder Freeway before his 43-tonne semitrailer crashed into the back of the Volkswagen on December 6, 2021.
Two-year-old Harriett was killed instantly while her parents Simon Peckitt and Felicity Stewart were hospitalised with serious injuries.
Livingston has pleaded guilty in the Victorian County Court to culpable driving causing Harriett's death, as well as negligent driving causing serious injury to Mr Peckitt and Ms Stewart.
He also admitted endangering 10 other people in the vicinity of the crash, including Harriett's one-year-old sister Jemima who was next to her in the back seat.
In the 20 minutes before the collision, three drivers saw Livingston repeatedly swerve in and out of his lane, even coming close to a family stopped on the side of the freeway.
Each of the motorists overtook Livingston either for their own safety or to check whether he had fallen asleep.
There were also several signs in the 400m before the crash site telling drivers to slow to 40km/h because of roadworks.
Livingston didn't hit the brakes until 0.91 seconds before the collision, striking the almost stationary Volkswagen at 86km/h.
The semitrailer then veered to the right, hitting a Toyota Hilux which rolled and trapped another driver for about two hours.
Three other cars were struck either by the Volkswagen or the Hilux, while several other motorists were forced to move their cars off the road to avoid being hit.
A sleep disorder expert said the crash was very likely caused by Livingston's sleep deprivation and his driving in the lead-up was consistent with a person having micro-naps.
But defence counsel Phillip Bloemen told the court Livingston felt adequately rested before the collision so he was contesting any claims he was sleep deprived.
Livingston reported being distracted by his surroundings and zoning out before the crash but he did not fall asleep, Mr Bloemen said.
Judge Michael Tinney said even if Livingston wasn't fatigued or falling asleep, his lack of concentration was reason enough to stop driving.
"He doesn't respond to any external event outside the car - not once," the judge said on Tuesday.
"A reasonable person in that sort of setting is going to pull over, aren't they?"
Mr Bloemen conceded it was an aggravating feature if Livingston was aware of how he was driving but he did not pull over.
Prosecutor Grant Hayward said the judge should find that Livingston was not in a fit state to drive and yet he continued to do so.
"It was an entirely avoidable collision," Mr Hayward told the court.
The prosecution accepted Livingston was remorseful, as was evident through his distraught comments to police and his early guilty plea.
But the objective seriousness of the offending was high and a substantial jail term was warranted, Mr Hayward said.
Mr Bloemen accepted prison was the only available sentence but he asked Judge Tinney to take into account Livingston's early plea, his remorse and his good prospects of rehabilitation.
Livingston's bail was revoked and he was remanded in custody ahead of his sentencing hearing on Friday.
