The A12 has now re-opened between Junctions 18 and 19 following an earlier crash.
Emergency services were scrambled to the northbound carriageway between Chelmsford and Boreham at around 5.30pm.
One casualty was cut free from a vehicle by firefighters.
All lanes have now re-opened but delays are back as far as Junction 15, at Ingatestone.
There are also long delays on all surrounding routes.
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