The four-mile section of motorway between junction 6 at Hale and junction 8 at Bowdon is one of the busiest in the North West carrying 100,000 vehicles a day.
An extra running lane will be added to both the westbound and eastbound carriageways to tackle congestion and provide more reliable journeys for city centre commuters and businesses as well as tourists using the airport.
Technology will also be installed to manage vehicles through the upgraded motorway while four emergency areas will provide refuge in the event of break downs.
A contraflow system will be in operation from the start – helping to reduce the number of carriageway or full motorway closures needed during construction.
Main construction work will complete by March 2022.
Highways England project manager Clare Bond said: “The start of the main construction work is a significant milestone for this project, which will ease congestion and make journeys more reliable once it opens to drivers in 2022.
“This is one of the busiest sections of motorway in the North West but using the contraflow system during construction will allow us to keep all the motorway lanes open during the day with occasional overnight lane and carriageway closures.”