The £1.5bn project – one of Britain’s biggest road upgrades – will increase the route to three lanes in each direction and is expected to cut 20 minutes off journey times.

The upgrade will include the construction of a major new bypass for Huntingdon, which will widen both the A1 between Brampton and Alconbury and the A14 between Swavesey and Milton.

There will also be improvements to the junctions at Bar Hill, Swavesey, Girton, Histon and Milton.

The new bypass is scheduled to be open to traffic by the end of 2020, however, some work will continue for longer.

Jim O’Sullivan, chief executive of Highways England, said: “The A14 is one of the most important east to west road links in the country, connecting businesses, communities and families.

“These vital improvements have been highly anticipated, and it is great to be able to start main construction today [28^th November].

“We have worked very hard to get the project to this stage and I would like to thank all our local partners who have supported us and worked with us to get this far.

“I want the A14 to redefine what a road scheme can achieve and, in addition to a significantly upgraded road, I am determined that our work here will leave behind a positive legacy for people living along the A14 – providing better, safer journeys, setting hundreds of young people off on fulfilling careers in construction, and boosting the capacity of the whole country to deliver world-leading infrastructure improvements.”