Santino Bankal, 28, was a disqualified driver behind the wheel of an unregistered car when motorbike rider Ashleigh Gason, 21, collided with his car on the Nepean Highway at Brighton in July 2017.

Following the crash, the Ballarat resident told his then-girlfriend: "Something has hit us. We have to get out. The car is on fire."

Witnesses and passers-by tried to extinguish the flames and help the motorcyclist, who died at the scene.

Bankal and his girlfriend retrieved their dog from the burning car before he told her: "Let's just go home and we'll sort out what we're going to do."

The Sudanese immigrant later said he "freaked out and ran away".

The County Court of Victoria was told on Tuesday that Bankal spent only 60 to 80 seconds at the scene before fleeing in a move Judge Sue Pullen described as "inhumane, callous and cowardly".

He had previously pleaded guilty to one charge of failing to render assistance after an accident, driving while disqualified and driving an unregistered motor vehicle.

Judge Pullen noted Bankal was not being sentenced for causing Mr Gason's death.​

Bankal's lawyer had argued his departure from the scene did not change the outcome for Mr Gason, but the judge said that was "not the point".

"Your failure to render assistance in the circumstances ... was callous on the extreme," she said.

A report showed Bankal did not suffer from post traumatic stress disorder, thought disorders or mental illness.

However, it was noted he was a psychologically and emotionally "unsophisticated man" and "almost childlike".

"He's not silly. He knew full well he was in a lot of trouble," Judge Pullen said.

"He clearly left the person he knew was there on the road at the scene."

Judge Pullen said Bankal left because he wanted to avoid repercussions for driving unlicensed in an unregistered car, and for breaching a community corrections order.

Bankal, who has already served 41 days in custody, was sentenced to three years and three months' imprisonment, and must serve at least 22 months in jail before being eligible for parole.

He has been disqualified from obtaining a driver's licence for six years.

- AAP