Work will begin to demolish a damaged footbridge over the A21 in Tonbridge this week.
The work, on the bridge above the A21 at Barnetts Wood, will begin at 10pm on Friday and finish at 5am on Monday, dependent on the weather.
The lay-bys in both directions between the Morleys interchange and Vauxhall interchange will be closed from 10pm on Friday to maintain to the safety of the public and road crews.
A full carriageway closure will take place from 8pm on Saturday until work ceases on Monday.
The original bridge design and the nature of the demolition work means it is not possible to take it down in sections, therefore it is necessary to close both carriageways.
The demolition is being carried out following a traffic collision with the section in 2013. It was made safe at the time for traffic, but it cannot be used by pedestrians and is necessary to remove it before placing it in the future.
"Removing the bridge and replacing it in the future is the safest option for pedestrians and road users alike" - Kevin Bown, Highways Agency
Kevin Bown, Highways Agency asset manager said: “Safety is a top priority for the Highways Agency. Following the road traffic collision last year we identified issues with the bridge, which while not compromising traffic safety in any way, meant that pedestrians could not access the crossing.
"Removing the bridge and replacing it in the future is the safest option for pedestrians and road users alike."
During the closures there will be signed diversion routes. London-bound road users wishing to join the A21 from the A26 will following a route via the A26, A2014, A26, A227 and the B245.
Those wishing to continue on the A21 will be diverted off at the Vauxhall interchange to the A27, A227 and the B245 with coast-bound users following the same diversion in the opposite direction.