Programme overview


The A9 is often described as “the backbone of Scotland”. At 273 miles (439km) it is the longest trunk road in Scotland. It must be safe, reliable and resilient, and that is why the Scottish Government is committed to dualling the A9 between Perth and Inverness.

The A9 Dualling programme will upgrade 83 miles (133 kilometres) of road from single to dual carriageway. This £3.7 billion (at April 2023 prices) Programme is one of the largest road infrastructure programmes in Scotland’s history. 

Dualling the A9 between Perth and Inverness will strengthen the connection between the Highlands and Scotland’s Central Belt for communities and business, bringing vital benefits for all road users, including bus services, through safer roads, improved journey time reliability and reduced driver frustration. It will also provide enhanced active travel routes for walkers, cyclists and horse riders.

A9 Dualling Objectives

The objectives of A9 Dualling are:

  • Improve the operational performance of the A9 by reducing journey times and improving journey time reliability.
  • Improve safety for motorised and non-motorised users by reducing accident severity and reducing driver stress.
  • Facilitate active travel within the corridor.
  • Improve integration with public transport facilities.

Delivery Plan

The Programme involves dualling 11 projects which have been developed individually. Road users are already benefiting from the Kincraig to Dalraddy and Luncarty to Pass of Birnam projects, which became operational in September 2017 and August 2021 respectively. In December 2023, a delivery plan for completion of A9 Dualling was announced in the Scottish Parliament. This plan will use a combination of design and build contracts and, subject to further decision making in late 2025, Mutual Investment Model contracts (a type of public-private partnership contract) to complete dualling works. You can see further details on the Delivery Plan section.


The estimated total scheme cost of A9 Dualling is £3.7bn, at April 2023 prices. When adjusted for inflation, that is equivalent to £2.45bn at April 2008 prices, which is well within the original cost estimate of £3bn at 2008 prices.


A9 Dualling will provide a variety of benefits to users, as well as the communities and businesses served by and around the A9. This includes:

  • Improved journey time reliability - dualling will reduce the journey time on the entire route from Perth to Inverness by 20%, saving approximately 26 minutes
  • Improved resilience on the route by limiting the need for lengthy diversions
  • Improved safety – three less fatality casualties and eight less serious injury casualties forecast annually
  • Reductions in driver stress and journey times for emergency vehicles
  • Better non-motorised user routes, provision of dedicated grade-separated crossings of the A9 and enhanced lay-bys for accessibility to the surrounding countryside
  • Improved public transport integration, providing assistance for bus operators by reducing journey times, improving operation performance and safer access to local communities and railway stations, together with replacement bus stops on the route and provision of new bus turning facilities