Drivers have been warned the A421 will close from 8pm on Friday (16 November) to 6am on Monday (19 November).
The closure will be in place from the Eagle Farm roundabout to Junction 13 of the M1.
A council spokesman said: “The closure will allow our team to move utility pipes and lampposts, and remove trees and hedgerows as part of the initial work, ahead of completing the dual carriageway.
“We try to limit any road closures to during the least busy times. However, at certain key stages we do need to close the road for the safety of our workers and the public.”
The team working on the A421 improvements are holding a free public drop-in event on Thursday 29 November for any questions or queries you may have
“We’ll be in the area just outside the Tesco and Costa Coffee stores from 12 noon to 8.30pm at the Kingston Centre Shopping at Winchester Circle, Milton Keynes MK10 0BA,” the spokesman added.