Traffic through the centre of Aberdeen has halved since the opening of the city bypass three months ago.
Data collected by the Scottish Government, and revealed by the First Minister on a visit to the north-east yesterday, indicates that about 50% of drivers who would have clogged roads in the heart of the city have diverted onto the AWPR instead since its completion in February.
Transport Scotland has also found that journey times from the south of the city to Dyce have halved – even during rush hour.
Figures show that the morning commute from Stonehaven to Dyce took an average of 47 minutes before the new road opened, with the same drive in the evening taking 42 minutes.
Both journeys now take 18 minutes on the AWPR, the government body said.
Nicola Sturgeon hailed the effect of the bypass as she visited the Aker Solutions base in Dyce.
The SNP leader said: “The AWPR has brought huge benefits to the north-east with these initial findings showing both journey times and congestion have improved over the last few months.
“Vehicles that were previously sitting in nose-to-tail traffic and causing pollution have now shifted, leading to lower emissions in the city.
“This has the potential to improve air quality for about 75,000 homes and will improve the environment for pedestrians and cyclists in Aberdeen.”
Transport Scotland has stressed that the statistics were taken from “early snapshot data” which should only be viewed as indicative, as more formal monitoring will take place over a longer stretch of time.
The 36-mile bypass stretches from Stonehaven to Ellon, around the western edge of Aberdeen.
Over the next 30 years, the £745 million route is expected to be worth £6 billion to the north-east economy and it is tipped to create about 14,000 jobs.
The reduction in congestion could also allow for a more pedestrian-friendly city centre, as well as improving air quality.
But business leaders, including the heads of Opportunity North East (One) and Aberdeen and Grampian Chamber of Commerce, have already begun pushing for more major infrastructure projects to be carried out.
Chief executive of One, Jennifer Craw, said: “It is important we maintain the momentum in infrastructure investment to support international growth in our key sectors with enhanced harbour and port facilities, air connections, and road and rail links.”
Russell Borthwick, from the Chamber of Commerce, added: “Although we celebrate the fact we have the AWPR, it took far too long to deliver it.
“What we need to force home as a region is the need for pace if we are to continue to punch above our weight in our contribution to the national economy.”