A 20-mile stretch of the A14 will be closed early next year as work to resurface the road and extend its lifetime gets underway.
National Highways, which maintains the country's road network, has announced plans to start work on the project next February.
It said the roads designed between the 1950s and 1970s are reaching the end of their life span and are in need of repair.
The A14 between junction 47a for Haughley and junction 49 at Tothill, outside Stowmarket, is set to be upgraded as part of the works.
However, National Highways has confirmed the road between junctions 43 and 51 from Bury St Edmunds to Needham Market – almost 20 miles in distance – will be closed for two weeks to construct a contraflow.
The A14 will only be closed in one direction at a time.
Once the contraflow is constructed, the road will be reduced to one lane in both directions and the speed limit dropped to 50mph.
When the A14 is closed, a signed diversion route will take drivers up to Stuston, near Suffolk's border with Norfolk.
A statement on National Highways' website said: "Our repairs will help improve the safety of the road surface, but it will also provide a smoother and quieter journey for road users.
"Rather than repairing the potholes and cracking, the whole carriageway will be reconstructed and re-laid to ensure a smoother and safer ride.
"Once complete, we expect the life of the road surface to be extended by up to 40 more years, with fewer future closures for maintenance repairs, meaning more reliable journeys for road users."
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