There were severe delays of four miles on the Orwell Bridge after a two-vehicle crash.
Police were called to the crash involving a lorry and a car in the westbound carriageway at about 4.30pm on Monday.
A spokesman for Suffolk police said that no serious injuries have been reported as a result of the crash.
In a tweet National Highways has confirmed that one lane had to be closed and there was delays of around 35 minutes in the area.
Queues were building back to the A12 turn-off.
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