Lorry driver arrested over Dartford M25 crash
A lorry driver has been arrested after a crash that closed the M25 clockwise carriageway at Dartford, causing tailbacks and disruption.
Kent Police said a car and a lorry were involved in a collision at junction two at 03:45 GMT. The car damaged a barrier on a flyover during the crash.
One man remains in a serious condition in hospital and three others were treated for minor injuries.
A 45-year-old man has been arrested on suspicion of dangerous driving.
He remains in police custody.
Highways England said the barrier had been replaced, allowing two lanes of the three-lane carriageway to reopen.
The barrier was on a section of the M25 where it passed over the A2, a spokesman for Highways England said.
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He said a temporary barrier was installed during the afternoon to allow the two outside lanes to reopen.
The inside lane would remain closed until a new permanent barrier could be installed, which was expected to take a week to manufacture.
Traffic lights were adjusted around Junction 2 to improve the flow of traffic, he added.
BBC Travel said traffic was queuing from the Darenth Interchange for seven miles (11km) back to Junction 30, near Lakeside shopping centre in Essex at the height of the disruption.