Emergency repair work to underpin the A14 at Rougham, which had subsided after a £12 million project to improve the Rookery Crossroads, will start at the end of the month.
After investigations, the Highways Agency found cavities in a drainage crossing trench, 3m below the road, which they intend to fill with grout as a temporary fix while investigations into a permanent solution continue.

Officers hope the grout will stabilise the road, which suffered repeated subsidence after the completion of the Rookery Crossroads scheme in 2006.

Brian Pitkin, route performance manager for the Highways Agency, said: "Since the subsidence first appeared, our main priority has been to keep the road open and safe.

"Identifying a long-term solution has proved to be particularly difficult. We appreciate the inconvenience this has caused and we ask for the patience of road users at this location," he said.

Although a preliminary design for the permanent repair is being developed, no timescale has yet been set for the work, which is scheduled for the end of the year.

David Ruffley, MP for Bury St Edmunds, said: "Although we will have to wait until later in the year for a permanent solution, I'm sure motorists will be reassured to know the voids under the carriageway will soon be filled to provide a temporary solution to the problem."