Work starts today on a controversial average-speed camera project on the A9 Inverness to Perth road.
The milestone was announced as Transport Scotland prepares to host a series of exhibitions outlining route options for dualling the remainder of the route.
By installing about 100 cameras between Inverness and Dunblane, the A9 Safety Group – led by the Scottish Government roads agency – aims to cut the death toll, reduce speeding and improve safety.
The £2.5million scheme has faced stiff criticism from campaigners, including local MP Danny Alexander, who claim Transport Scotland would do better to speed up plans to dual the road from the current deadline of 2025.
The first phase will focus on erecting columns and installing cameras and infrared lighting masts on single carriageway sections of the road.
The work is being carried out at 27 sites along a 138-mile stretch.
Engineers will calibrate and test the equipment prior to it going live in October.
A9 Safety Group chairman Stewart Leggett said: “The A9 Safety Group is clear that the deployment of average speed cameras on the A9 will improve safety for all users by improving driver behaviour and reducing the unacceptable levels of speeding currently recorded on the route.
“Average speed cameras have proven effective in reducing casualties where they have been deployed and they are a key part of the wider plan to improve the safety of everyone using the A9, both in advance of, and during the dualling of this vital route.
“The average speed camera system is only a small part of the overall investment making up the interim safety plan for the A9. We are committed to maintaining the route and managing its safe and effective use, both before and during the forthcoming dualling programme.”