Nicola Sturgeon has said the Aberdeen Western Peripheral Route (AWPR) will be “transformative” for people and businesses across the north-east of Scotland.
The bypass was fully opened in February, having initially been expected to be completed by spring 2018.
It was delayed by factors such as the weather and the collapse of construction firm Carillion.
Speaking at the Aker Solutions AWPR business event on Monday, the First Minister said the 36-mile long bypass is estimated to have cut journeys in Aberdeen city by up to a half.
“As everybody here knows, the opening of the Aberdeen Western Peripheral Route (AWPR) has been a long time coming – I think that probably qualifies for the understatement of the decade,” Ms Sturgeon said.
“I want to take the opportunity today of paying heartfelt tribute to everyone whose hard work, dedication and expertise contributed to what is a remarkable achievement.
“And I think I must also pay tribute to the people of Aberdeen, whose persistence has really ensured that eventually this project had to come to fruition.
“I’m also grateful to everyone who has been involved in the Go North East campaign.”
The road was built under a £745 million fixed-price contract but in December contractors told MSPs delays had resulted in hundreds of millions of pounds in additional costs, taking the overall cost to more than £1 billion.
Over the next 30 years it is expected to bring an additional £6 billion to the north-east economy, according to Transport Scotland, and help create around 14,000 jobs.
Ms Sturgeon said: “It’s estimated that – in the long-term – the AWPR will help to cut journey times across Aberdeen by up to half.
“That will be transformative for people and businesses, right across the north-east.
“And – while it’s still early days – and it’s important to stress that – we’re already seeing some major and very significant improvements.”
The First Minister added: “It will enable Aberdeen to be a cleaner, healthier and even more beautiful city than it already is.
“It will open up new economic opportunities and help businesses to thrive.
“In doing so – we hope it will contribute to the common good that Tom Johnston spoke of – of people throughout the north-east – and across the whole of Scotland.”