Work begins on dualling A9 from Inverness to Perth
Construction work has begun on the A9, marking the start of a project to upgrade the road to dual carriageway between Inverness and Perth.
Five miles (8km) of road from Kincraig to Dalraddy, south of Aviemore, will be the first of 12 sections to be tackled.
The overall £3bn scheme has been described by the Scottish government as the biggest ever transport project undertaken in Scotland.
It is not expected to be completed until 2025.
Before any work could begin on the Kincraig to Dalraddy section, conservationists were brought in to gather up rare wood ant colonies for relocation.
The construction of the new stretch of dual carriageway is due to be completed by 2017 at a cost of £35m.
It will involve excavating 700,000 tonnes of rock and soil.
Infrastructure, Investment and Cities Secretary Keith Brown said the start of the work was a "milestone" in one of the "most challenging" infrastructure projects in Scotland's history.
He said: "I am very proud that the Scottish government is delivering this major upgrade and, in the weeks and months ahead, people will now see work on the ground as the road progresses.
"When this ambitious programme is complete, enormous economic and social benefits will be felt by communities along the length of the road, and beyond.
"Today sees the first spade in the ground, with work beginning in earnest to see the programme through to a successful finish."
Stewart Nicol, chief executive of Inverness Chamber of Commerce, said the government's commitment to the project should be welcomed.
But he added: "It is going to take too long. We have called for the Scottish government to bring this forward as fast as they can.
"We welcome their commitment to it, but we need to see this upgrade done quickly."
The A9 stretches for about 245 miles (394km) from central Scotland to Scrabster near Thurso in Caithness.
It is Scotland's longest and the UK's fifth longest trunk road.
Of the about 110 miles (177km) of road between Inverness and Perth, only about 30 miles (48km) is dual carriageway.
Separately, there is also work under way to improve the road at the Berriedale Braes between Inverness and Thurso.
That project is likely to go to a public inquiry before any construction work can begin.
Dualling the A9 has been a long-standing commitment of the Scottish government.
However, the Scottish Association of Public Transport has previously called for the investment to be put into upgrading the railway network instead.