This dopey female driver saw a police van parked up on the side of the road and thought it would be an excellent idea to slam her brakes on with a fully loaded lorry behind her on cruise speed. Point is love, unless you are actually breaking the speed limit, there is no need whatsoever to brake. You are damned lucky not to have been booted up the arse!!
Female driver.
A303 eastbound between southfields and hayes end roundabouts