A cyclist in Western Australia has posted video to YouTube showing the terrifying moment that a driver who had almost forced him off the road got out of his car and wielded a knife at him.

The footage was uploaded to the video sharing site after the motorist involved, driving a 4×4, had been fined A$1,500 after the video was passed to police. The title shot is from the rider’s helmetcam while the main footage is shot from a camera mounted on his bike’s handlebars.

Shortly beforehand, he had made a very close pass on the cyclist at the approach to a roundabout, which resulted in the rider banging on the vehicle to make the driver aware he was there.

The driver then stopped his vehicle and stepped out into the road, brandishing a knife at him.

Understandably, the rider backed away.

It’s not clear whether the YouTube user, who goes by the name Search for YOUR REG, was the actual cyclist involved.

Last week, footage emerged of a motorist in north west London threatening a cyclist with a baseball bat after passing him and immediately turning left.

> Video: Driver cuts up cyclist – then threatens him with baseball bat

The driver in that incident backed down once he realised he was being filmed.