Work to upgrade the main road to the Highlands is under way.
Ground investigations began as part of the plan to dual an 80-mile stretch of the A9 Perth-Inverness trunk route.
Scottish Finance Secretary John Swinney visited to check progress on the Luncarty to Pass of Birnam section.
"The £3 billion complex and challenging programme will be one of the biggest infrastructure projects in Scotland's history," he said.
"The sheer scale of it means that it will require in-depth planning and design to ensure that we deliver the right project at the right price and keep impacts on communities, business and the environment to the absolute minimum.
"So, we are moving ahead with our plans, which will bring benefits for local communities, road users and businesses, including improved road safety and journey times, and reduced times for businesses transporting goods and services."
The contract for the Luncarty-Pass of Birnam section was awarded to Environmental Scientifics Group and will require 25 full-time staff for the 10-week site works.