CAVITIES beneath the road have been identified as the cause of the problems that caused a stretch of the A14 to subside, the Highways Agency has said.

CAVITIES beneath the road have been identified as the cause of the problems that caused a stretch of the A14 to subside, the Highways Agency has said.

The agency said ground penetrating radar survey was carried out at the Rookery Crossroads in January along both the eastbound and westbound carriageway after the problem arose last year.

It said the results were analysed and highlighted and there were areas below the road surface which could indicate the presence of cavities or less dense materials.

The agency is now considering the options for filling these cavities in the short term which will then allow time for the design of a permanent solution.

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."

A preliminary investigation to establish the ground conditions and involving taking core samples took place in the summer.

Further and more extensive investigations involving CCTV and ground radar was conducted at night under the road surface in January to determine a permanent solution.