Delayed Aberdeen Bypass could be open by Christmas
It has been one of Scotland's biggest infrastructure projects, costing around £1bn.
The long-awaited Aberdeen Bypass could be completed later this month.
At a Holyrood committee on Wednesday, Stephen Tarr, of contractor Balfour Beatty, confirmed that completed sections of the 28-mile route will open to commuters next week.
The road between Stonehaven, Charleston and Craibstone, however work on a bridge over the River Don will continue until later in December.
The development of the Aberdeen Western Peripheral Route (AWPR) is one of the biggest infrastructure projects in Scotland.
The cost was expected to be £745m when the project was given the go-ahead in 2009.
Wednesday's committee heard it could now cost more than £1bn.
Lewis Macdonald, North-East Labour MSP, asked Mr Tarr: "If I were to put to you that the total cost of the project was over £1bn, would you accept that was broadly correct?"
Mr Tarr said: "Yes, I think from what we've said you could deduce that those are the areas of the costs."
There are currently discussions between the contractors and Transport Scotland about who is liable for the extra costs.
The road was due to be completed in spring this year but bad weather, the collapse of one of the contractors, Carillion and problems with a bridge over the River Don has caused delays.
The completion date was then moved back until autumn.
However, last month Scotland's Transport Secretary said contractors were hoping to finish in December.
Other sections of the road have already been open for several months.