Most of the delayed Aberdeen bypass will open next week with the final section due by Christmas but the cost will reach £1 billion, its builders told MSPs today.
The news came as transport secretary Michael Matheson attacked the “misguided and ultimately pointless tactics” of contractors in delaying a 20-mile section by two months.
This southern stretch of the 36-mile route between Stonehaven and Craibstone, near Aberdeen Airport, is due to start carrying traffic, along with an east-west prong from Cleanhill to Charleston on the southern outskirts of Aberdeen.
It was completed on 5 October but has been caught up in a legal wrangle over the need to change the project contract to enable open the section ahead of the rest of the road.
The final Craibstone-Parkhill stretch, over a new bridge over the Don, will follow when faults with the crossing have been repaired.
The northern sections of the road, between Parkhill and Tipperty, opened this summer.
The project - officially the Aberdeen Western Peripheral Route - was due to have opened in spring last year, which was later postponed to November last year.
Contractors Balfour Beatty and Galliford Try - working as Aberdeen Roads - also revealed it had spent several hundred million pounds because of the delays, and the total cost of the scheme would top £1 billion.
It had been due to cost £745 million, but the consortium hopes to recoup some of their extra outlay from the Scottish Government's Transport Scotland agency.
However, neither side would say how much was being claimed.
The consortium told the Scottish Parliament's rural economy and connectivity committee the project had been delayed by the collapse of fellow contractor Carillion, "the worst flooding in the region since record began" and problems with moving power and water cables and pipes.
It said that on the Don bridge: "The remedial works are currently forecast to be complete just before Christmas, which would allow opening of the full project; albeit that is a challenging programme as the works are highly susceptible to adverse weather, and are subject to stringent safety tests."
Mr Matheson said of next week’s opening: “This is the news we have all been waiting for.
“I have explored every possible avenue with Aberdeen Roads (AR) to open this section of road as soon as possible and I am delighted my efforts to bring this matter to a positive conclusion have been successful.
“I made it clear to them my strong desire to get the road open would not be at any cost and Scottish Ministers are simply not willing to pay over the odds for the road on account of mistakes or miscalculations that are of the contractors’ own making.
“I am sure the people of the North East will join me in a sense of relief and even excitement that a large part of this transformative road is finally opening.
“But they will also share my deep sense of frustration at AR’s misguided and ultimately pointless tactics.”
In a statement to the committee, the contractors said: “The contract provides for that section to be completed and handed over in one go.
“However, while the road part is now complete, the bridge requires repairs – so it is not complete.”