A Yallingup man has detailed a dramatic pursuit in which he risked his life to stop an erratic driver allegedly throwing rocks at oncoming traffic.
South West Police said they received a report about 9.15am on Saturday, November 2, of a vehicle being driven erratically by a man on Bussell Highway and Caves Road.
Jarryd Foster said he was travelling to work on Caves Road when the vehicle swerved at him and the driver allegedly threw a large rock - shattering the car window.
"I slammed on the brakes and did a U turn because I thought I was being personally attacked," he said.
"I was in shock. Initially, I was angry, but then the adrenaline kicked in."
Mr Foster said he chased the motorist down while calling police and gathering details of the vehicle.
After passing the vehicle outside the Yallingup Maze, Mr Foster said he reversed into it several times in an attempt to get it off the road.
However, the tactic failed and, suddenly, the cars were both on the road again - only now with several cars heading straight towards them.
Mr Foster said it wasn't until more bricks and rocks were thrown at the oncoming traffic that he realised the incident was not personal and frantically began trying to alert approaching motorists.
"I really started freaking out," he said.
"That's when I knew it wasn't personal, that he was trying to get anyone.
"There were eight cars in front of me and I was waving and screaming at them to give them every warning I could.
"He would swerve in front of them, throw a rock and swerve back."
Margaret River man Michael Earl was with his wife and two children on their way to Perth when they noticed cars ahead of them pulling off the road.
"We thought maybe they were pulling over because there was a branch on the road, or something like that," Mr Earl told the Mail.
"Then we've seen about four cars in front of us pull over and we're face to face with this car in our lane."
It was then that Mr Foster took matters into his own hands, forcing the vehicle off the road into a pile of Grass Trees and subsequently trapping the driver in the car.
Upon hearing the police sirens, Mr Foster said he hopped out of the car, threw his hands up and told officers he had done nothing wrong.
"The police were incredible - we were a team," he said.
"They could not have been better. The police treated me so well."
The rampage left a trail of destruction, with multiple vehicles damaged and several of the occupants taken to hospital for treatment.
However, miraculously, there were no serious injuries.
"It was pretty surreal, standing back and looking at the scene," Mr Foster said.
"I could see parts of my car 70 metres up the road.
"I would rather die than live with the fact that I could have stopped someone from losing their life."
Mr Earl said his wife saw the rock being thrown by the man and said, given the speed and force of the projectiles, those involved were lucky to not be seriously injured or killed.
It is understood the driver of the vehicle is currently in hospital undergoing assessment and has not yet been charged.
South West Police have called on members of the public that may have witnessed the incident or obtained dash cam footage to contact 131 444.