Work to facilitate the opening of new third lanes in both directions along the A130 between Howe Green and the Rettendon Turnpike is set to begin in March.
The additional lanes have been completed but remain coned off after a routine inspection highlighted issues with crash barriers along the route.
Further investigation work over recent months has revealed a need to reconstruct the ground alongside the carriageway as a preventative measure to protect against the risk of slippage in the long-term.
Essex County Council is working with CountyRoute, who run the A130 on behalf of the Council, to ensure the works will not encroach on the current dual carriageway.
The work is expected to be completed this summer and will not cost Essex taxpayers thanks to an agreement with CountyRoute.
Cllr Eddie Johnson, Essex County Council Cabinet Member for Highways and Transport, said: “I completely understand the frustration of seeing a coned off section of the A130 but safety has to be at the forefront of our thinking.
“The dual carriageway remains open as usual and we are working hard with CountyRoute to ensure we can open the new third lanes as soon as possible.
“We expect the works will be completed this summer.
“I’d like reassure the public that, thanks to the arrangement we have with CountyRoutes, these works will not cost taxpayers a penny.”
Work to create a third lane in both directions on the A130, between Howe Green and the Rettendon Turnpike, was originally triggered in the summer of 2015 after 50,000 cars used the stretch of road in one day.
It comes 14 years after the northern section was first opened in January 2002 following a deal with CountyRoute, in which it was chosen by Essex County Council to construct and operate the road.