A9 upgrade to shift to Slochd Summit near Inverness
Engineers are to investigate how to tackle one of the most challenging sections in a project to upgrade the A9 trunk road between Inverness and Perth.
The Slochd Summit, south of Inverness, is the second highest point on the A9 after the Drumochter Summit at 401m (1,315ft) above sea level.
The road at the Slochd is one of 12 sections of the A9 being upgraded from single to dual carriageway.
Ground investigation work there is due to start early next week.
A traffic management system will be in place during the work which is expected to take five weeks to complete.
Transport Scotland's A9 dualling project is to be completed in 2025 at a cost of £3bn.
Economy Secretary Keith Brown said: "Building on the vital ground investigation work that has already taken place across the dualling programme this year, this latest ground investigation contract will take place along a very challenging part of the route totalling over 15 miles which includes the dramatic rockface at Slochd.
"We hope to identify the preferred route for this section next year and these investigations will help inform the design work at the next stage."