Drivers have been warned the A421 will close from 8pm on Friday February 15 until 6am on Monday February 18.
The closure is to allow both the Cranfield Road Bridge and the footbridge neat Hulcote to be extended to accomdate a wider A421.
As part of the project Cranfield Road bridge will be closed from 8pm on Friday January 25, until 6am on Monday January 28.
A spokesman added: "To extend the permanent bridge on Cranfield Road, we’ll need to close it from May 2019.
"The bridge is expected to be closed for up to 14 months whilst the improvements are done. We are working with our contractor to reduce this period, if possible."