The video (click here to view) shows that the Ford Fiesta driver almost causes a pile-up on a busy dual carriage after driving right in front of the HGV and opening his door just before the two vehicles collide.

He then jumps from his car and starts remonstrating with the innocent lorry driver while standing on the fast lane of the dual carriageway.

The Fiesta driver then gets back into his car before pulling over again and aiming more abuse at the lorry driver. Both vehicles stop again and the drivers finally exchange details.

As the whole incident was captured on a SmartWitness CCTV camera, the footage proves conclusively that the driver of the Fiesta was to blame.

SmartWitness managing director Simon Marsh said: ‘This video perfectly illustrates why more and more of Britain's fleets now have in-cab cameras.

‘It captures a road rage incident where tempers are running high and the driver of the Fiesta is behaving very irresponsibly.

‘Without the SmartWitness footage, it would be just be a case of one driver's word against another – with a messy insurance claim dragging on for months with no clear blame established.

‘With the SmartWitness footage, it is clear from outset that the Fiesta driver is clearly to blame.’

Just 2% of collisions caught on SmartWitness camera result in disputed claims – against an industry norm for all motor insurance claims of 40%.