Four major national companies are bidding to carry out the first phase of work to dual the A9 Inverness-Perth road.
Work on the five mile section from Kincraig to Dalraddy will start next year.
It has been brought forward because of anticipated savings from the Queensferry Crossing.
The Scottish Government plans to dual the length of the route from Perth to Inverness as part of their £3billion programme.
The four contractors shortlisted for the Kincraig work are: BAM Nuttall/John Sisk; Farrans Construction/Roadbridge; Morrison Construction; and Wills Bros/John Paul Construction.
The contract will be awarded next summer.
It will involve widening the existing stretch of single carriageway between Kincraig and Dalraddy to full dual carriageway, providing overtaking opportunities in both directions, cutting the number of vehicle convoys and reducing driver frustration.
Transport Minister Keith Brown said: “The announcement is a reflection of the Scottish Government’s ambitious programme of investment and commitment to dual the A9 from Perth to Inverness by 2025 and I welcome the interest shown by construction companies who are keen to secure the contract.
“Work to progress the dualling of the A9 is gathering momentum as we move another step closer to appointing the contractor who we expect to put the first spade in the ground next summer, some six months earlier than originally planned.
“This contract, along with the two of the three multimillion-pound design contracts for the route and work to address safety issues, will continue to drive forward improvements to Scotland’s longest trunk road. This will deliver benefits for road users and local communities alike, while supporting businesses, communities and tourism throughout Scotland by improving access to and from the Highlands.”