Ground investigations have begun to try to find a solution to a notorious hairpin bend on the northernmost section of the A9.
The trunk road drops from 150m (492ft) to 20m (65ft) as it enters a valley at the Berriedale Braes in Caithness.
The three week exploratory work will see the physical characteristics of the soil analysed to help identify possible improvements.
Transport Minister Keith Brown was on site to see drilling work begin.
He said the government expected to have a preferred option in place by next summer, with the focus on easing the problem for HGVs and other long vehicles in particular.
"This is just one element of our ongoing work to improve the A9 with the ambitious programme to dual the route between Perth and Inverness, the first government ever to commit to do so," he said.
"Work is gathering pace with surveys underway and the procurement of the three design contracts about to get underway."
The £90,000 contract for these works was recently awarded to BAM Ritchies.
Transport Scotland provided additional funding to cover the total cost of the ground investigations.