The new charges related to an incident in Oamaru in May 2020, when Chellew failed to stop for police, instead accelerating away and reaching speeds of up to 130km/h.
The court heard that Chellew and his passenger threw bottles, pieces of wood and other items at the following police car and attempted to ram it.
When the pursuit came to an end, Chellew punched Woodbridge, grabbed him around the throat, squeezed his neck and genitals and jumped on the police vehicle. It took two officers to arrest him.
Woodbridge read his victim impact statement to the court before sentencing.
Aged 50 at the time of the incident, Woodbridge said he knew Chellew reasonably well, through work and a sports club in Oamaru.
The assault caused him numerous injuries, including a broken nose, sprained thumb, cuts on his arm that required stitches, concussion and bruises and grazes on his body and face.
Woodbridge said he had played contact sport his entire life, and had experienced previous concussions.
"But on this occasion, I really appreciated it as a brain injury, as it lasted a lot longer," he said.
"Two days after the assault, I tried to get out of bed, but I couldn't stand. I was dizzy and wanted to vomit."
Woodbridge was taken to hospital and diagnosed with delayed concussion, had to take two weeks off work, and was not allowed to drive.
"Psychologically, it really shocked me.
"There were four times during this where I thought Joshua could kill me; throwing bricks and firewood at the car, ramming the police car, when he tried to take my police baton off me — I thought of Peter Umbers — and when he had me by the throat and groin and was squeezing tight."
In 1990, Senior Constable Umbers was beaten to death with his own baton after stopping a robbery suspect in Ranfurly.
Woodbridge said Chellew had apologised to him in a letter and in person at his bail address.
Chellew had agreed to take part in a restorative justice process, but Woodbridge and his fellow police officer declined.
"He does his victims a real disservice by continuing his abuse of drugs. I accept he is an addict, but he needs to take responsibility and get help."
Defence counsel Paul Norcross said Chellew's response to the charges had been anything but flippant.
"He hasn't made light of anything in his instructions to me."
A family member spoke up for Chellew, saying he refrained from using drugs while on bail, and did a lot of work at home, and towards his stablehand licence.
In sentencing, Judge Maze said both police officers involved had expressed their shock at the events and the potential for more harm.
She said Chellew's pre-sentence report was not particularly positive, but he had complied with bail conditions for a considerable period, and had positive support from some family members and a good work history.
He also had a significant history of offending and was clearly seriously affected by the fatal crash three years ago.
Judge Maze said Chellew's mental health issues were exacerbated by intermittent substance abuse, and there was a risk of further offending.
"Right now you are receiving significant positive support, and you are showing respect for that and the potential for change arises from it."
