Resurfacing work starts next week on the Stoke Hammond and Linslade Western bypass.
Closures will be in place during the works, sometimes during the daytime, meaning there is likely to be an impact for those travelling in and out of Aylesbury.
Bucks County Council say three road surfacing teams will work on the £4.5 million project, which involves closing each carriageway completely for around four weeks - starting with the Milton Keynes-bound lanes on Monday - to allow work to be done quicker.
The work involves removing the entire surface course, which has a number of defects, and, in areas where investigations have found structural weakness, replacing some of the lower layers.
During the first week both carriageways will close overnight - from 7pm on Wednesday 15 August to 6am on Thursday 16 August and provisionally from 7pm on Thursday 16 August to 6am on Friday 17 August - to allow the Chelmscote roundabout to be prepared for a new surface that weekend the following weekend.
Bucks County Council's deputy leader and cabinet member for transport Mark Shaw said: "We have decided to opt for alternate full carriageway closures to give contractors a clear run along the five-mile length, to get the job done more quickly, to better control costs, and to maintain road safety for motorists.
"I appreciate that road works aren’t possible without some degree of inconvenience, and I apologise in advance for this.
"However I believe this comparatively short burst of pain will be worth it for the many years of ‘gain’."
Traffic from the Aylesbury direction on the A418 will divert from the A4146 roundabout at the Wing end, via the Leighton Buzzard bypass, A505, and A5 to meet the A4146 again at Kelly's Kitchen roundabout just outside Bletchley.
Traffic from the Milton Keynes and Bletchley directions will divert on to the A5 at Kelly's Kitchen roundabout, via the A505 and Leighton Buzzard bypass to join the A418 at the roundabout near Wing.
Subject to good weather the schedule for the works is as follows:
Monday 13 August to Friday 17 August - Northbound (towards Milton Keynes) carriageway closed completely for surfacing teams to remove and replace surface material.
Southbound carriageway (towards Wing) and Chelmscote roundabout will remain open during the day but will be closed overnight (7pm-6am) on Wednesday 15 & provisionally on the Thursday 16 August.
Weekend 17- 20 August (7pm Friday to 6am Monday) - bypass closed completely to allow Chelmscote roundabout resurfacing.
Monday 20 August to Friday 31 August - Northbound (towards Milton Keynes) carriageway closed completely for surfacing teams to remove and replace surface material.
Southbound carriageway (towards Wing) will remain open during the day but will be provisionally closed overnight (7pm to 6am) on Wednesday 29 & Thursday 30 August.
Weekend 31 August to 3 September (7pm Friday to 6am Monday) - bypass closed completely to allow Soulbury Road roundabout resurfacing.
Monday 3 September to Sunday 9 September - Northbound (towards Milton Keynes) carriageway closed completely for surfacing teams to remove and replace surface material. Southbound carriageway (towards Wing) will reopen.
Weekend 9-10 September (7pm Sunday to 6am Monday) - bypass closed completely to allow plant and equipment to be transferred from northbound to southbound carriageway.
Monday 10 September to Sunday 7 October - Southbound (towards Wing) carriageway closed completely for surfacing teams to remove and replace surface material. Northbound (towards Milton Keynes) carriageway will reopen.
Provisionally, there will be a North and Southbound closure for one night on Friday 28th September to install road markings to the Soulbury and Chelmscote roundabouts.
Sunday 7 October - bypass reopens completely.