A Sydney truck driver has been ordered to spend at least three years in jail for a crash that left two people seriously injured in 2014.

Sarmad Nisan, 42, disobeyed multiple warning signs about the steep descent on Warringah Road, Dee Why, as he hurtled towards the intersection of Pittwater Road.

The 22-tonne truck, which was almost fully laden, overturned onto waiting cars as it failed to negotiate the corner.

A Mazda 2, being driven by police officers Amy Champion and James McClenahan, took the brunt of the crash and both suffered a range of serious injuries.

Nisan was last year found guilty of two counts of dangerous driving causing grievous bodily harm.

Six people were injured when the truck smashed into eight cars, crushing one of them. ( ABC News: Greg Hatch )

In total, six people were injured.

The crash happened at one of Sydney's busiest intersections.

'Gross departure' in standards

Judge Deborah Payne said it was a gross departure from the expected standards of a truck driver.

"In my view, no penalty other than full-time imprisonment is appropriate in this case," she said.

Nisan was driving in the wrong gear, was travelling too fast and failed to engage the exhaust brake.

"This case is certainly not one of momentary inattention or misjudgement," Judge Payne said.

"He has never taken responsibility for his offending.

"I do not find his remorse to be genuine."

In addition to his jail sentence, Nisan has been disqualified from driving for two years.

Senior Constable Champion indicated that she was pleased with the sentence and disqualification and was relieved the case was over.

The judge imposed a total sentence of four years but Nisan will be eligible for parole in April 2020.