bbc.co.uk/news/uk-england-35547288
A crash has closed the M25 clockwise carriageway at Dartford, with tailbacks and warnings of disruption.
Kent Police said a car and a lorry were involved in a crash at junction two at 03:45 GMT. The car damaged a barrier on a flyover following the collision.
One man was seriously injured and three had minor injuries. All four were taken to hospital.
Highways England said the barrier must be replaced before the road reopens.
The barrier is on a section of the M25 where it passes over the A2, a spokesman for Highways England said.
He said a temporary barrier would be installed on Thursday afternoon to allow the two outside lanes to reopen.
The inside lane will remain closed until a new permanent barrier can be installed, which is expected to take a week to manufacture.
Traffic lights have been been 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.
Diversions are in place.