A9 dualling project

The A9 dualling project is an ongoing infrastructure project in Scotland to upgrade the A9 between Perth and Inverness from a single carriageway to a dual carriageway. A dual carriageway allows drivers to overtake safely, as they do not have to meet oncoming traffic; and the crash barriers on the central reservation greatly reduce the frequency of head-on collisions. As most of the A9 is currently a single carriageway, drivers may have to overtake heavy goods vehicles (HGVs) and other slow-moving vehicles as they are limited to 50 miles per hour (80 km/h), 10 miles per hour (16 km/h) lower than the speed limit for cars and motorcycles. The A9 has been dubbed Scotland's most dangerous road. In 2022, there were 17 fatalities, its highest level in 20 years before falling to four in 2023.

The project was announced in 2011 in response to the safety concerns with overtaking and head-on collisions. Construction started in 2015 starting with a 5-mile (8 km) section between Kincraig and Dalraddy (near Aviemore) followed by the 6-mile (10 km) Luncarty to Pass of Birnam in 2019. This project was originally due to finish in 2025, but has since been delayed to 2035. As of 2025, two out of eleven sections have been completed, totalling 11 miles (17 km), leaving 77 miles (124 km) to be upgraded. The sections between Tomatin and Moy, as well as between Tay Crossing and Ballinluig are under construction as of November 2025. Both sections are due to be finished in 2028.