Traffic built up on the A14 at Stowmarket after a deer was struck by two vehicles.
The incident involving a Ford Focus and Toyota Prius happened shortly before 3pm on Tuesday, Suffolk police said.
One lane of the eastbound carriageway between junctions 50 and 51 was blocked following the collision and a rolling road block was put in place at Haughley.
An ambulance crew has been called to the scene, though the extent of the injuries is not yet clear.
A Suffolk police spokesman confirmed the incident had been cleared by 5.15pm.
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