The two-night scheme involves repairing the road surface and laying high friction surfacing. Line markings and road studs will be replaced where necessary.
The westbound carriageway will be closed between its junctions with the Rising Sun Island and White Horse Road from 6.30pm to 6.30am each night.
Traffic will be diverted off the A5 at the B5011 Chase Road and carry on along Lichfield Road and the A452 to rejoin the A5 at the Rising Sun Island.
Highways Agency Project Manager Richard Gulliver said:
This work will improve skid resistance and prolong the life of the carriageway. It will be carried out overnight when traffic flows are lightest and the diversion route is a short one, but we still advise road users to allow extra time for their journeys.
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.