Construction will support around 1,500 jobs and over 100 apprenticeships, graduate places, and other training opportunities.

The scheme will be delivered in stages, with completion expected in winter 2017, around six months ahead of schedule.

The contract to construct, maintain, finance and operate the new roads, which is the largest contract to be awarded as part of the Scottish Government’s Non-Profit Distributing (NPD) model, was awarded to the Aberdeen Roads limited consortium of Balfour Beatty, Carillion and Galliford Try.

Mrs Sturgeon, said the beginning of the largest road scheme of its kind anywhere in the UK now underway was “a landmark day for the north-east”.

The first minister added: “As the oil and gas capital of Europe, Aberdeen is a major driver for the Scottish economy and I am determined we do all we can to improve infrastructure and transport links to ease commutes, boost business and keep Aberdeen internationally competitive.

“The scheme is already bringing short-term economic benefits through £221m of sub-contracts, either put to the market or soon to be advertised, and longer-term benefits estimated to bring £6 billion of investment and 14,000 jobs to the north-east over the next thirty years.

“During construction alone, the bypass is expected to bring around 1,500 jobs during its peak, and over 100 training and vocational places which will ensure our young people get valuable opportunities to enter the workplace. Scotland has the highest employment and economic activity rates, and lowest unemployment, including youth unemployment, of any of the four nations in the UK – and it’s clear the Aberdeen bypass is contributing to this success.

“The start of work today is a big win for local communities, businesses, and road users and will bring much needed early relief to the congestion we see in and around Aberdeen on a daily basis.”

Cabinet secretary for infrastructure Keith Brown added: “Over 58km of new road, a dozen new junctions, 14 miles of new slip roads, two new river crossings, and 150 other structures will soon be delivered. Our carefully planned management of the scheme’s procurement will see junctions around Aberdeen airport finished next year, the Balmedie-Tipperty section of the A90 finished ahead of schedule in spring 2017, and completion of the entire scheme by winter that year, some six months ahead of the original schedule.

“There have been many challenges to get us on the road, but I’m delighted construction of this new bypass is now underway to deliver for businesses, commuters and communities right across the north-east.”