Transport Secretary, Chris Grayling, visited Cambridgeshire this morning (November 28) as work started on the £1.5 billion A14 upgrade.
The road will span a total of 21 miles between Huntingdon and Cambridge, adding additional capacity to the network with three lanes and cutting up to 20 minutes off journey time for thousands of motorists.
Plans also include a major new bypass for Huntingdon, widening the A1 between Brampton and Alconbury, widening the existing A14 between Swavsey and Milton, and improving the junctions at Bar Hill, Swavesey, Girton, Histon, and Milton.
"In the evening commute between Cambridge and Huntingdon, it can take over an hour to travel just 17 miles," Mr Grayling said, after visiting Swavesey this morning.
"Towns and villages such as Godmanchester and Fenstanton suffer from traffic caused by drivers trying to avoid jams. And the road's safety record isn't good enough.
"So the existing 40-year-old A14 is no longer fit for purpose. Thanks to the work we've started today, in just four years' time it will be possible to drive between Huntingdon to Cambridge confident of arriving on time.
"The first half of the journey will take place on a far quieter road - thanks to the new Huntingdon bypass taking traffic from the west around the town, not through it. And the remaining half of the journey will be on a three-lane carriageway with capacity to serve commuters, long distance motorists and freight from the east coast ports."
The A14 is the 33rd major scheme the government has started since 2010, with more than £4 billion already invested in new roads.
The new bypass and widened A14 will open in 2020, with work on removing the A14 viaduct in Huntingdon expected to continue for some time after.