The total closure of the dual carriageway for seven miles between the north and south junctions for Tonbridge will run from 10pm on Friday February 14 to 6am on Monday February 24.
It will last for nearly ten days rather than four, as was planned last month, and promises to cause chaos in Tonbridge with all traffic being diverted through the town centre.
Major repairs will be undertaken on the Medway Viaduct flyover above Haysden after faults were identified a year ago. Highways England will also rebuild Manor Farm subway near Leigh.
The surface of the bypass was breaking up due to problems with the movement joints in the viaduct. Seven cars were damaged by one pothole on January 14.
The works, previously scheduled for January 8-13, were postponed because of supply chain issues. The latest timing runs during the half-term holidays.
Around 35,000 vehicles use the route between Hastings and the M25 every day, and drivers now face a half-hour addition to their journey time.
Local MP Tom Tugendhat and Tonbridge & Malling Borough Council Leader Nicolas Heslop previously voiced their concerns about doing the work during term-time.
Southbound traffic will be diverted at the Sevenoaks Weald exit and sent along the B245 through Hildenborough on to the A227.
Vehicles will then be signposted to turn left at the top of the High Street on to Bordyke and Hadlow Road, then take a right on to Cannon Lane.
They will follow the A26 though the industrial estate to where it turns off at Vale Road, and rejoin the bypass at the Vauxhall roundabout.
Northbound travellers will follow the same route in reverse. It is also feared that drivers will use the High Street instead, adding to the existing congestion.
There will also be selective overnight lane closures beforehand, from Monday [February 10] to Thursday February 13 from 8pm to 6am.
Tonbridge & Malling Borough Council Leader Nicolas Heslop said: “I can understand why the works are needed, as the bridge is failing.
“It is important to acknowledge that Highways England listened to the fears that we raised about the original timing and the lack of any notice.
“The intervention from Kent County Councillor for Tonbridge, Michael Payne, was particularly important.
“While we have succeeded in moving the works to the half-term week, when there ought to be less traffic, it is inevitable that we will experience congestion in Tonbridge, especially at peak hours. This remains a concern.”
A spokesperson for Highways England said: “We have scheduled the work in one go rather than over consecutive weekends, following feedback on previously planned timings.
“We’re also using half-term week when there is less school run traffic. As delays are expected during this work, we advise you to plan your journey and allow extra time.”
