The work, which will take place between 8pm and 6am from Monday evening until Saturday morning, will include resurfacing the road, repainting white lines and replacing road studs on the A46 between the M4 junction 18 slip road and the Cold Ashton roundabout.
Rachel Scott, Highways Agency Project Sponsor, said:
As well as record increases in road improvements we’re also investing in keeping our roads properly maintained and safe for road users.
We have planned this work exceedingly carefully when traffic flows are at their lowest to ensure it causes the least disruption to road users.
As well as working overnight and avoiding the weekends we will also be lifting all work from the morning of Thursday, 1 May until the evening of Monday, 12 May to avoid causing disruption during the Badminton Horse Trials and over the bank holiday.
All works will be completed by the morning of Saturday, 17 May.
Road users travelling northbound on the A46 will be directed to follow the A420, then the A417, A432 before rejoining the A46 at Old Sodbury.
Road users travelling southbound will be directed to follow the same route in reverse.
The diversion routes will be clearly signed.
Members of the public should contact the Highways Agency Information Line on 0300 123 5000.
Journalists should contact the Highways Agency press office on 0844 693 1448 and use the menu to speak to the most appropriate press officer