Engineers are to carry out radar tests to find out why a section of one of the busiest roads in south Essex is sinking.
Parts of the A127, on the outskirts of Southend, subsided seven inches in just a fortnight.
Emergency repairs were carried out on a section of dual carriageway, near Progress Road, earlier this month.
It was believed the subsidence may have been caused by the long, hot summer.
But engineers from Southend Borough Council are preparing to use ground radar to find out if there are gaps under the road surface which could have caused the problem.
They are in talks with contractors, and say they hope to carry out the tests as soon as possible.