The A14 will be closed in both directions from 9pm tonight (Friday, September 14) to 6am on Monday (September 17) as two bridges are installed at Bar Hill.
The new bridges will replace the old bridge which will be demolished in 2019.
Traffic travelling eastbound toward Cambridge will be diverted to leave the A14 at Godmanchester (junction 24), follow the diversion via the A1198, and A428.
Through traffic travelling westbound toward Huntingdon will follow the same diversion in reverse. Those travelling westbound from Bar Hill will be able to access the A14 towards Huntingdon but it won't be possible to travel eastbound on the A14 from Bar Hill.
Traffic going eastbound will be diverted via the westbound A14 to Godmanchester and join the through traffic diversion towards Cambridge.
People can watch the work via a live stream online by visiting the A14 Cambridge to Huntingdon social media channels and website.
Highways England is upgrading a 21-mile stretch of the A14 between Cambridge and Huntingdon to three lanes in each direction including a new 17-mile bypass south of Huntingdon, with four lanes in each direction between Bar Hill and Girton.
The project, which includes 34 bridges and main structures, will increase capacity, boost the local and national economy and cut up to 20 minutes off journeys.