Work to try and improve Braintree's most congested roundabout will begin on February 2.
The work to Galleys Corner is part of a Government scheem to tackle congestion hotspots and improve road safety.
A Highways Agency spokesman said: "The work will mostly involve overnight lane closures, with 50mph speed restrictions on the A120, restrictions on the local roads approaching the roundabout, and some full closures of the A120 between Panners and Marks Farm roundabouts."
Adam Schwalm, Highways Agency Project Sponsor, said:
“By widening parts of the roundabout at Galleys Corner and encouraging use of two lanes, traffic flow on the approach to and through the roundabout will improve. This should help to reduce congestion, particularly during the busier peak periods. We will also use this opportunity to upgrade the existing lighting and replace drainage.
“The majority of this work will take place overnight to avoid causing disruption to motorists travelling during the busy periods. Some weekend lane closures of the A120, between Marks Farm and Panners roundabout, will be required for safety reasons. Drivers who might be affected by this work are advised to plan ahead and allow extra time to travel through the area while work is ongoing.
“I would like to thank road users and residents in advance for their patience while this work takes place.”
Work is due to begin at 8pm on Sunday 2 February and be completed by 6am on Thursday 13 March. It will mostly take place between 8pm and 6am.
The work will largely involve overnight lane closures and 50mph speed restrictions on the A120, approaching and on the roundabout. Restrictions will also be in place on the local roads approaching the roundabout – Long Green, B1108 and Cressing Road – with clearly signed diversions in place.
During the scheme, some full closures of the east and westbound A120 between Panners and Marks Farm roundabouts will be required. Details of these closures and the diversion routes will be publicised in February once work has started.