Work to dual the entire A9 between Perth and Inverness has been driven further forward.
The Scottish Government has announced the consultants who will study how best to complete the £3 billion upgrade of the notorious route.
The government has pledged to finish the stretch of road by 2025, improving safety and boosting the economy as a result.
Halcrow will carry out preliminary strategic environmental assessment and Jacobs will undertake preliminary engineering work.
They have been tasked with examining how the programme may be packaged into individual projects, with seven lengths of single carriageway 80 miles in total to be widened, while keeping the road open.
They will look at issues such as laybys, and ”active travel facilities”, including better paths for walkers, cyclists and the like.
Transport Minister Keith Brown said: ”Work to dual the A9 by 2025 is gathering pace with the award of two major contracts this week. This £3 billion complex and challenging programme will be one of the biggest infrastructure projects in Scotland’s history and will ensure safer roads, less congestion and a better quality of life for road users and local communities.
”We are the first government to commit to a full A9 dualling programme. This commitment will deliver major economic benefits to road users, businesses, communities and industry who live along or use this important lifeline route between central Scotland and the Highlands and Islands.
”This will also be the first time that the whole A9 corridor between Perth and Inverness has been looked at. The work these contractors are undertaking will give Transport Scotland a much fuller understanding of the route and set the foundations for the detailed design.
”The project is further evidence of the Scottish Government’s commitment to supporting the economy by competently delivering major infrastructure projects.”
Transport Scotland said it intends to consult fully with affected communities and businesses ahead of work beginning.
Public exhibitions will be held in early December in venues along the route to give the public a chance to have their say on the project and how it could affect them.