The Scottish government has revealed work to turn the A9 between Inverness and Perth into a dual carriageway will not be completed by its 2025 target.
MSPs committed to the project in 2011, when it was predicted to cost £3bn.
Transport minister Jenny Gilruth said on Wednesday that completion by 2025 was “unachievable”.
She revealed that the project had been hit by delays, highlighting the impact of the Covid pandemic, Brexit and the war in Ukraine.
Ms Gilruth said: “I fully appreciate that this will be disappointing news for many people. However, I want to be absolutely clear to the communities and businesses served by the A9 between Perth and Inverness, that the Scottish Government’s commitment to dualling the section between Tomatin and Moy is unaffected.
“This procurement process coincided with external factors including the pandemic, disruption caused by Brexit, and the war in Ukraine, with the inflationary impacts of those all affecting significantly the construction market.
“This has been a difficult decision to make but we believe it to be the right, and indeed the only responsible one to take in all the circumstances. However, let me assure everyone that Transport Scotland is already taking the necessary preparatory steps for the urgent re-tendering of the Tomatin to Moy project.
“Work has begun to update contract terms and work will continue on preparations for the new procurement for Tomatin to Moy, with the firm aim of achieving a contract award before the end of 2023.
“It is true that the target date set always represented an ambitious challenge.
“It was reliant on the timely and positive outcome of a range of factors such as completing public and stakeholder consultation; statutory approval processes; market capacity; supply chain availability and availability of funding, all of which have been significantly impacted by the events I outlined earlier.
“This has made this 2025 date simply unachievable.”
Conservative MSPs have argued that dualling the A9 would save lives after it was revealed that deaths on the road in 2022 were at their highest level since 2010.
Over the last ten years, 11 miles of road totalling two sections have been dualled – leaving work to be completed around 77 miles of road.
Ms Gilruth added: “Transport Scotland is urgently considering a range of different options to provide Ministers advice on the most efficient way in which to dual the remaining sections. That consideration will include updating the evaluation of options involving the use of design & build contracts, to reflect changes to contractual terms and conditions developed from engagement with the construction industry. I expect to have that advice by Autumn 2023 at which time I will update Parliament to put forward a renewed timescale for completion.
“Our investment of over £430m to date means much has already been achieved and while much is still to be done, this Government is absolutely committed to completing the A9 Dualling programme.
”I announced an investment of approximately £5m in additional road safety measures for the A9 back in December. I am pleased to confirm that these have now commenced and are progressing well, as confirmed by BEAR Scotland at the A9 Safety Group last week in Inverness.
“This includes enhancements to signing and road markings, initially between Birnam and Dalguise, and installation of eight electronic signs to display safety messages at key locations between Perth and Inverness. Furthermore, a road safety campaign targeting driver fatigue will begin on February 13 and preparations for a drive on the left campaign are well underway ahead of an Easter launch.”