Brutal dash camera footage shows the moment a furious driver punches a fellow motorist several times through his open window.
At the start of the video a Vauxhall Corsa and BMW vie for position on the A127 flyover in Southend, Essex.
The black Corsa speeds into the inside lane before swiftly swerving back to the outside lane in front of the BMW.
As traffic slows, the BMW tries to get past on the inside lane but is blocked off by the other car, not once but twice.
Having come to a standstill, the driver of the Corsa jumps out of his vehicle to confront his fellow motorist.
After a short exchange of words, the Corsa driver, wearing a navy T-shirt and grey jogging bottoms, slams the BMW door shut before launching three punches through the window.
He then opens the door again to throw a further four blows before being interrupted by another driver and the passenger in his own car.
The video was shot by a parcel courier – who wishes to remain anonymous – while driving in his van on Friday, June 17 at about 11.55am.
The courier said: ‘When I pulled onto the flyover, the two cars in question came into the camera view from over the flyover on the right hand side.
‘The smaller Corsa was tailgating the BMW and then cutting in front at the top of the video abruptly.
‘I can only assume the drivers had issues over giving way coming onto the flyover as it’s only a single carriageway.
‘Unfortunately I could not hear what was being said between the two or what the black van driver said to stop it.
‘The traffic built up pretty quickly so I did not see what else happened with the vehicles.’ “