The A47 Fen Road will be closed overnight from 8pm to 6am tonight (March 16) and tomorrow night (March 17).
The essential works undertaken by National Highways will aim to improve the Guyhirn junction.
A diversion route will be in place for motorists.
Eastbound traffic will exit the Whitepost roundabout at Thorney onto the A1139, then continue onto A605 Fletton Interchange, take the slip road onto the A605 through Whittlesey and Coates to the A141, and re-join the A47 at Guyhirn.
Westbound traffic will follow this diversion in reverse.
National Highways said: "We try to minimise any disruption during our works, but there may be some unavoidable noise such as reversing bleepers on vehicles.
"Residents directly impacted by these closures have been contacted about accessing their property."
For the most up-to-date information about the county's roads, visit our LIVE Cambridgeshire traffic map.
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Do you have a live or breaking news story from across Cambridgeshire? Email: cambslivenews@archant.co.uk
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