Work to extend a section of the A130 to three lanes in both directions is set to begin this summer.
The Third Lane scheme on the A130 between Rettendon and Howe Green is currently midway through the design process.
It is anticipated that the programme of works will start in July and last approximately four to six weeks.
The work has been triggered after more than 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, a subsidiary of John Laing, which was chosen by Essex County Council to construct and operate the road.
The majority of the works will be completed under full carriageway closures at night between 8.30pm and 6am.
Only one direction will be closed at any one time with suitable diversions in place along Main Road and Southend Road.
Where possible, supporting works will be undertaken during the day either within hard shoulder closures or, if needed, with off-peak daytime one lane closures between 10am and 3.30pm.
Annual resurfacing works have been bought forward so they can be undertaken at the same time to minimise disruption to the members of public who use the road.
As well as resurfacing, other works such as lining and sign installations will be undertaken along with other planned routine maintenance to fully utilise the road closures whilst they are in place.
Carriageway closures will be suspended for Brownstock Festival between 8 – 10 July and V Festival between 19 – 21 August to help support the anticipated increase in traffic that weekend.
Cllr Rodney Bass, Essex County Council Cabinet Member for Infrastructure, said: "This is very much a planned scheme, triggered under our agreement with CountyRoute, and to be constructed under the terms of that agreement earlier than expected because of higher than anticipated volumes of traffic.
“It is relatively easy to deliver as we had the foresight to make provision for this in the original design and layout of this road.
“We will be using mainly night-time closures to ensure minimal disruption for road users.”
More information regarding the closures will come out in due course once the programme has been finalised.