Both followed the car, with Wishart calling police at 5pm as he drove. He was still on the phone when a police car came screaming past in pursuit.
The truck was swerving back and forth across the road, tyres belching smoke as he skidded, Wishart said.
"When cars came toward him he would swerve into their path and drive them off the road. Every corner we went round you got the feeling we would come across a scene of carnage."
He characterised it as a "low-speed dangerous chase" as it was hard to drive faster than 70km/h on the windy road.
Wishart described seeing the truck swerve into the path of oncoming cars, and said it appeared the driver was "playing chicken".
"I was waiting for impact but luckily the cars avoided him by driving off the road into ditches," he said.
"He wasn't just fleeing police, he was out to wreak mayhem."
The chase proceeded through Riverhead, with police laying road spikes just after the township and that punctured the truck's front tyres.
The truck continued on its rims for another 8km at about 20km/h past Coatesville Village. Police were coming from the other direction when the driver tried to take a corner, lost traction and burst into flames as it came to a stop.
A police spokeswoman said officers began pursuing a truck on Old North Rd at 5.03pm that had been involved in two earlier collisions.
Police requested backup from the police Eagle helicopter and also deployed road spikes. The pursuit was abandoned due to the manner of driving, she said.
The Eagle stayed in pursuit of the vehicle, which eventually caught fire and stopped. The driver attempted to escape on foot.
A man, 24, was arrested and has been charged with unlawfully taking a motor vehicle, assault, reckless driving and failure to stop, police said.
