This shocking footage shows a trucker and a Mercedes driver who had a dangerous game of cat-and-mouse on the M25.
The flat bed-lorry, which had a white van on the back, veered into the inside lane of the 70mph motorway.
The manoeuvre forced the black Mercedes driver to slam on their brakes.
The Mercedes was forced into the slip lane leading onto the eastbound M40 towards London.
The truck then went into the slip road before returning to the inside line and then briefly to the middle lane.
The Mercedes driver tried to get back into the inside lane before being forced back into the slip lane.
The motorway was packed with other cars at the time.
It happened on Tuesday at Junction 16 of the M25, near Denham, Buckinghamshire.
The flat bed-lorry, which had a white van on the back, veered into the inside lane of the 70mph motorway
The manoeuvre forced the black Mercedes driver to slam on their brakes
The Mercedes was forced into the slip lane leading onto the eastbound M40 towards London
The 40-second game of cat and mouse was captured on mobile phone footage by a shocked passenger in another vehicle travelling behind.
Locals blasted the foolish behaviour which could have ended in a pile-up.
Carla Wiland said: ‘What is this nonsense? Imagine driving, minding your business, and then get hit by one of these.’
Richard Lee added: ‘These are standard numpties on the road. They’re everywhere these days.’
Maureen Dalton said: ‘Honestly the driving in this country is getting worse.’
Others claimed: ‘The Mercedes probably started it,’ and ‘This is standard UK road behaviour now.’
Thames Valley Police has been approached for comment.