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Falkirk to Thurso

At 273 miles, the A9 is Scotland's longest road and one of the country's most important transport links. It begins at Junction 5 of the M9 motorway, running through Falkirk & Stirling before becoming a trunk road. It connects Stirling, Perth, Inverness & Thurso and intersects several other major routes on its way north. It also crosses the Kessock, Cromarty and Dornoch Firths, key links north of Inverness.

As a main link through Scotland, the route has been subjected to several major overhauls. The most recent occurred between 1972 and 1986, with 130 miles of new road built between Perth and Inverness. Plans are now in place to convert the whole of this section to dual carriageway.

A9 - Construction near Birnam (1970s).

Route Origins

The A9 corridor has been in use for over 500 years. Historically, Drove Roads were the main pathways that people used to travel from the Highlands to the Lowlands, following the line of least resistance through the valleys. The first work on this route came in 1725, with the construction of a military road from Dunkeld to Inverness. This was overseen by General George Wade, the military commander sent to the Highlands to provide military resistance to the Jacobite uprising. Approximately 250 miles of road was built across the Highlands, with several large bridges being constructed, primarily to transport military supply wagons and troops between forts such as Ruthven Barracks, near Kingussie.

By the 19th century the need to improve transport across the Highlands became apparent. In 1803, the Commission for Highlands Road & Bridges was set up by parliament to improve communications across the north of Scotland. Thomas Telford oversaw much of this work, constructing approximately 870 miles of road and building over 1000 new bridges. Many lengths of Scotland's main roads still follow the original Telford road with little deviation.

A9 Key Projects - Construction Summary


Opening Date

Dunblane Bypass

10th December 1990

Auchterarder Bypass

21st October 1983

Perth Western Bypass

17th September 1985

Dunkeld Bypass

9th May 1977

Killiecrankie to Calvine Ph2

19th August 1986

Dalwhinnie Bypass

28th June 1976

Kessock Bridge

6th August 1982

Cromarty Bridge

12th April 1979

Dornoch Firth Bridge

27th August 1991

In the early 1920s the rise of the motor car led to further calls for improvements across the road network. The Edinburgh - Stirling - Inverness route was designated a Trunk Road and given the A9 number in 1922. Planners had initially decided to route the A9 over the Firth of Forth, taking a more direct route to Perth. This was ruled out due the ferry crossing at Queensferry, with this route instead given the A90 number.

A major part of the 1920s work was a rebuild of the Inverness to Blair Atholl section of the A9 to provide a modern 18ft carriageway, thus allowing for two way traffic. This involved replacing, bypassing or widening all the bridges. Major Robert Bruce was the main engineer for the works, while the consulting engineer for the bridges was Sir E. Owen Williams, a pioneer in the use of reinforced concrete for construction. Four large concrete bridges were built at Tomatin, Carrbridge, Newtonmore and Dalnamein. This work was completed between May 1924 and October 1928.


By the 1960s car ownership was on the rise, leading to a comprehensive redevelopment of Scotland's road network. While a motorway network was to link up the Central Belt, the A9 was looked at for improvement, particularly the section between Perth & Inverness. The initial plans were to bypass only the larger towns and provide overtaking opportunities. However, following a decision to construct the Kessock & Cromarty Bridges in 1972, it was announced that the road would be fully reconstructed to provide modern standards and bypasses along its entire length. This became Scotland's largest road project of the 20th Century, costing over £200m. The project, completed in 1986, involved the construction of many new bridges and was a significant engineering achievement.

From Stirling to Perth the A9 is a dual carriageway. North of Perth it mainly comprises a single carriageway with sections of dual carriageway making up around 30% of the overall route. North of Tore the road is entirely single carriageway. It was announced in 2008 that the 80 miles of single carriageway between Perth & Inverness would be upgraded to dual carriageway to improve safety and allow for continuous overtaking opportunities.

A9 - Slochd Pre-Upgrade (1960s).

In many places the A9 was completely rebuilt. Its original route took it through several towns and villages and it was often narrow and of poor quality. This photo shows the stretch near Slochd in the late 1960s.

Route History

Edinburgh to Dunblane
The original start of the A9 was at Maybury Junction outside Edinburgh. The road passed close to the old Edinburgh Airport runway, resulting in traffic being stopped regularly due to landing aircraft. A portion of this section was removed when Edinburgh Airport was expanded in the 1970s. Between Kirkliston and Falkirk, the A9 was renumbered as a series of A and B roads as part of the construction of the M9 motorway, built to relieve the congestion in the numerous settlements the A9 passed through.

In the 1990s, a new distributor road was constructed around Falkirk which extended the A9 to meet the M9 at Junction 5 (Cadgers Brae). At Stirling, a dual carriageway begins at Burghmuir Road as the A9 is routed along an Inner Relief Road, constructed in two stages in 1964 and 1970. This features a large underpass beneath Stirling Railway Station. Rejoining the historical route at the River Forth, it passes through Bridge of Allan and meets the M9 motorway once more at Keir Roundabout.

Dunblane to Perth
This is the first section of the route to be classified as a trunk road and is dual carriageway along its entire length. Work began on this section in 1967, with the decision to fully dual the stretch made in 1984 and achieved by 1992. The bypass of Dunblane was initially pushed back in the roads programme, with priority going to other routes. The main reason for this delay was that the old A9 through the town was partly dual carriageway, constructed in two stages in 1963 and 1971. The bypass of Dunblane was opened in December 1990.

A9 - Stirling Inner Relief Road underpass.

In Stirling, the A9 acts as a bypass of the city centre. A short section of dual carriageway, constructed in the early 1970s, was placed in a cut and cover underpass to reduce severance and maintain access to the main railway station.

The Dunblane and Greenloaning section was the first to be upgraded, primarily to allow for overtaking. The route here follows an old Roman Road, which explains its relatively straight alignment. Greenloaning was bypassed in 1969 and included construction of a grade separated fork junction for free flow connection onto the A822. The three mile section towards Blackford was delayed due to it being of a higher standard than the rest of the route. It was eventually completed in 1992. Large parallel access roads were built to link up the farm tracks and reduce the amount of at-grade turning areas along this stretch.

Blackford Bypass was the first major bypass to open, allowing the A9 to avoid the level crossing on the Highland Mainline. The scheme was delayed by a public inquiry, held due to proposals for only a single junction into the town. Some residents feared Blackford would lose crucial trade. The bypass was completed by Miller Construction in 1980. Two small improvements, opened in 1972 & 1975, take the A9 past Gleneagles and involved the building of the A823 junction. This was modified in 2010 to allow improved access to Gleneagles Railway Station.

The bypass of Auchterarder and Aberuthven had been proposed as early as the 1970s and was initially proposed as single carriageway, with increasing traffic flows later dictating the need for dual carriageway. This upgraded section was opened by MP Michael Ancram in October 1983. After crossing the River Earn, the dual carriageway encounters a steep hill climb and was opened in 1986. This was a notoriously slow section of the old road, resulting in long conveys of slow moving lorries, and many accidents. Large rock blasting and excavation was required to build the new road and substantial embanks to cross the River Earn. This connects to the final stretch towards Broxden Roundabout, completed in 1983.


Broxden is perhaps the A9's most important interchange. Unsurprisingly this leads to major congestion at peak hours and there have been many calls for improvements at this location. Average Speed cameras were installed on this entire stretch of the A9 in October 2014 in an attempt to reduce accidents at the numerous at-grade junctions.

A9 - North from Keir Roundabout

Perth to Inverness

Route History

The 110 mile section from Perth to Inverness is the most well known part of the route, being the main link to the Highlands from the Central Belt. Prior to any work taking place, the old road passed through numerous towns and villages, resulting in major congestion. Long convoys were common and there were few opportunities for overtaking. Winter resilience on the road was poor, with parts of the road at Drumochter closed for days at a time due to snowfall. The route was identified in the 1970 white paper for Scotland's roads as one requiring major improvement. Initial plans had been to provide bypasses and only limited investment.


In May 1972, Gordon Campbell, Secretary of State for Scotland, announced additional funding for the A9 project allowing work on the first eight schemes to get underway. By September 1972, the remainder of the schemes were announced, making up the 130 mile length of the road. The rerouting of the A9 north of Inverness over the Black Isle via the Kessock and Cromarty Bridges was also announced. A special A9 project team was set up by the Scottish Development Department to coordinate the reconstruction of the road which, by this stage, had been separated into 30 contracts. The team was led by Garston Miller, an Orcadian who became the superintending engineer of the A9 reconstruction project. The team consisted of engineers and officials who set out design standards for the new road and coordinated the various contracts.

Traffic flows at the time did not justify constructing the entire road to dual carriageway. However provision was made in the design of the single carriageway sections to allow for dualling in the future should traffic flows demand it. The alignment of the single carriageways would therefore be made of long, well aligned curves to allow overtaking, and to provide a suitable dualling alignment. Dual carriageway was incorporated where high traffic flows were expected or at steep gradients. Additionally, if the topography restricted the alignment of a single carriageway, and if any large structures were required, dual carriageway would be the preferred option.


Concern was raised by some local communities that business may die out due to the removal of through traffic. A policy was agreed by the Scottish Development Department that no service areas were to be built on the new A9 to protect business in the bypassed communities. This also led to trials of new types of signage showing the facilities available to road users in the various towns and villages.

In 1967, the Road Research Laboratory trialed a new type of roadside kerb. It has two protrusions designed to reflect driver headlights, therefore highlighting the edge of the road. Ultimately the kerbs were deemed unsuccessful, but they were used throughout the A9 upgrade and remain a rare feature on the Scottish road network. Their use was discontinued after 1983.

A9 - Inveralmond Roundabout (1975)

Inveralmond Roundabout marks the start of the 110 mile journey between Perth and Inverness. It also marks the northern extent of the Perth Western Bypass, shown here shortly after its completion in 1975.

Route Overview

The route between Broxden and Inveralmond forms a bypass of Perth, which opened in 1985. At Inveralmond, the A9 continues as dual carriageway for a further three miles before initially reducing to single carriageway, bypassing Luncarty and Bankfoot. A short dualled section then takes the route round the Pass of Birnam. As part of the A9 Dualling project, the dual carriageway was extended from Perth to Birnam and involved construction of a new junction for Luncarty & Stanley. It was opened in 2021.

The Birnam Bypass required large embankments alongside the railway line and passes in close proximity to Dunkeld & Birnam Railway Station. Large peat deposits lay in the road path and these were not to be disturbed to avoid subsidence of the nearby railway. Dunkeld Bypass was a technically challenging section of new road to design and build. South of the River Tay, two major crossings of the Highland Mainline occur within a mile of each other. Large retaining walls were built at the Hermitage and a crossing of the Braan was also built using Corten weathering steel.

The 225m Tay Bridge takes the A9 over the river. The main structure was assembled on the north side of the river and pulled over to the south. North of here, the course of the River Tay was diverted to allow the new road to run along the river valley. This involved hydraulic studies, with models created by Strathclyde University to assess the affect of the river diversion on the surrounding landscape. The bypass was opened in 1977 and received a Civic Trust award for how well it fitted into the landscape.

A9 - Killiecrankie Viaduct

Killiecrankie Viaduct, one of the most impressive structure's on the Scottish road network, was the last section of the A9 between Perth and Inverness to be upgraded. It was officially opened to traffic in August 1986.

At Ballinluig, a large five span overbridge takes the A827 over the A9. Formerly an at-grade turning point allowed access into Ballinluig, however safety concerns led to the construction of new grade separated slip roads for the northbound carriageway. These were technically challenging to construct given the close proximity of the Highland Mainline. A dual carriageway section takes traffic to the southern end of Pitlochry Bypass. This was also a challenging section to design and build, given the environmental concerns of the area, and led to several options for the new road alignment. Large bridges were required to cross the River Tummel and Loch Faskally, and a diversion of the old A9 was also required. The bypass was opened in 1981 and temporarily terminated on the old A9, adjacent to the B8019 junction for Tummel Bridge.

The Pass of Killiecrankie is a steep sided valley where road, railway and river all share a confined space. The upgrade of the road thorough here was particularly difficult with significant technical challenges. Several options were considered, one being a tunnel on the western side of the pass. Retaining walls were also considered to support the road to the East, but these were ruled out due to the size they would need to be and because of their visual impact on the area. 615m of dual carriageway is supported on a large viaduct structure carrying the road through the pass. This section opened in 1986, the last of the thirty contracts to be completed.

The A9 bypasses Blair Atholl on the south side of the River Garry, requiring two large bridges over the river. This opened in 1983 and connects onto a long section taking the road up to Drumochter Summit which was completed in 1978. This was the longest contract at 13 miles, and involved deep cuttings and embankments. Vast areas of peat were removed and several alterations were needed to the high voltage power line which runs close to the A9. A large section of this stretch runs along a split dual carriageway due to the challenging terrain and steep gradients. Substantial amounts of rock was removed and many watercourses were crossed by long culverts.

A9 - Drumochter Pass.

From Drumochter Summit the A9 slowly descends towards Strathspey, bypassing Dalwhinnie on a stretch that opened in 1976. The Newtonmore and Kingussie Bypass involved a seven span bridge over the River Spey, with a long embankment crossing the flood plain close to Ruthven Barracks. The first section of the A9 Dualling project can be found between Kincraig and Dalraddy, south of Aviemore and this opened in 2017. The bypass of Aviemore and Kincraig was held up by a 1975 public inquiry to discuss alternative routes for the A9. A popular option that emerged was to construct the new road on the other side of the valley, well away from the existing route, but this was ruled out due to the distance the new road would be from Aviemore & Kingussie.

Beyond Aviemore the A9 bypasses Carrbridge, the scheme involving a large bridge over the River Dulnain and major work further north at Slochd. A large bridge was built over the road and railway as well as massive rock cuttings and embankments to cross the Slochd Gorge. At the Slochd Summit (405m above sea level) the A9 has a dual carriageway section to bypass Tomatin, crossing the River Findhorn on a large five span viaduct. This was one of the first major bridges to be built with weathering steel in Scotland. The road bypasses Moy before taking a new route round the Meallmor Hill towards Daviot. Dual carriageway resumes and continues for nearly 15 miles past Inverness. Passing Milton of Leys is the start of a long descent towards Kessock Bridge. A major interchange connects the A9 to the A96 and a junction is provided for Inshes and Culloden. The stretch ends on Longman Roundabout, south of Kessock Bridge.

Enhancements to the A9 came in the 1990s due to a rising accident rate, resulting in improvements to junctions and new hatching installed on several bends to prevent overtaking. Further improvements came in the 2000s with the building of new overtaking lanes at Moy, Carrbridge, Kincraig and Newtonmore. These were the first of the new type of overtaking lane to be built in Scotland. The A9 from Kincraig to Crubenmore was rebuilt from 2004 to 2008 and new junctions were built at Bankfoot and Ballinluig. The short dual carriageway at Crubenmore was extended in 2011, and plans developed for dualling of the Luncarty to Birnam section as well as improvements between Kincraig and Dalraddy.


In 2008 the Strategic Transport Projects Review (STPR) confirmed that the A9 between Perth & Inverness would be upgraded to dual carriageway at a cost of nearly £3 billion. This will be one of Scotland's biggest road projects. Work began in 2015 at Kincraig and the first section opened in 2017. A second section in Perthshire opened in 2021.

A9 - Approaching Inverness from the south.

The Crossing of the Three Firths

In the late 1960s the Scottish Development Department announced that the A9 north of Inverness would be upgraded, not replaced. In 1968, the Highlands & Islands development board had commissioned a report by Jack Holms Development Company to look at the Inverness and Black Isle area and suggest proposals for redevelopment. The report proved controversial, and the main road proposals included widening of the existing A9 to dual carriageway along its original line.

Frustrated by the existing route’s lengthy and circuitous path round the heads of the Beauly, Cromarty and Dornoch Firths, locals Raey Clark and John Smith developed the ‘Three Firths Concept’, a proposal to build a more direct route for the A9. This, they argued, would improve the economic prospects of towns in the far north of Scotland. Three bridges were proposed as part of the plan: Kessock, Cromarty and Dornoch.

In 1969 local industrialist and Chairman of AI Welders Pat Hunter Gordon spearheaded a campaign to push the plans forward. Intense lobbying of politicians followed and in 1970, the Scottish Development Department (SDD) appointed consulting engineer Crouch & Hogg to investigate alternative routes. A significantly shorter route across the Black Isle was selected. The Scottish Development Department give the proposal the go ahead in September 1972. 


The initial design for Kessock Bridge envisaged a single A-framed tower supporting the centre span 29 meters high above the Beauly Firth. Tender returns came in well over £30 million, far higher than the initial estimates. After some design revisions, Crouch & Hogg teamed up with Ove Arup & Partners to restart the project. The SDD invited tenders for the new design shortly afterwards. The tender submitted by Cleveland Bridge & Redpath Dorman Long was accepted and construction began on the main structure in April 1978. The bridge was opened by HM The Queen Mother on 6th August 1982. You can read more about the planning, design and construction of Kessock Bridge here.

A9 Kessock Bridge - Aerial view from the north.

Kessock Bridge, an impressive harp-type cable stayed bridge, was completed in August 1982. Its construction was first proposed in the 'The Crossing of the Three Firths' campaign of the late 1960s.

Several contracts were let for the construction of the new road network across the Black Isle from North Kessock to Arduille. A new stretch of road from Tore Roundabout linking with the A835 towards Contin and Ullapool was also constructed. The projects were constructed between between 1975 & 1985.


Cromarty Bridge, a 1450m, sixty eight span concrete structure, was designed by Crouch & Hogg and constructed by Fairclough Ltd. Work began on the £4.5 million project in late 1976 and the bridge was opened to traffic in April 1979.


The A9 was improved to a high standard as far as Dornoch Bridge and included bypasses of settlements such as Evanton & Alness. Historically, the A9 north of Alness followed the route of the existing B817 through Invergordon before heading towards Tain. This was changed in the early 1970s and improvements were made to the new route passing Achnagarron Church and at Tomich Crossroads. Improvements from Boomhill Farm to Tain were not approved until the 1990s due to funding constraints and political interference. The section passing Calrossie Woods, was completed in 1997, the last original section of A9 to be improved between Inverness and Dornoch.

A9 Cromarty Bridge - View from the north.
A9 Dornoch Firth Bridge - View from the north.

The Cromarty and Dornoch Firth Bridges were completed in 1979 and 1991 respectively. Their construction led to significantly reduced journey times between Inverness and the far north of Scotland.

On bypassing Tain the A9 approaches the Dornoch Bridge. Discussions on the need for a bridge first began in the 1800s after the Meikle Ferry disaster. The first design for a bridge came from Robert Stevenson in 1831.


Today's Dornoch Firth Bridge, part of the Three Firths campaign, was always intended to be built after its neighbours at Cromarty and Kessock. Approval was given in 1988 and work began on the 890m long bridge in 1989. The construction consisted of the Cast-Push Method, with large prestressed concrete sections cast in a factory on the south side before being pushed over the piers to the north. When it opened, the £9.5 million, twenty one span structure was one of the longest bridges in Europe to be built using this method. Designed by Sir Alexander Gibb & Partners and Tony Gee and built by Christiani & Nielsen and Morrison Construction, it was opened to traffic by The Queen Mother on 27th August 1991.

The Far North

North of Dornoch, the road returns to its 1930s alignment with little deviation or modernisation. Major improvements at Loch Fleet were completed in 1988 before the A9 passes through Golspie and Brora. A Brora western bypass had been proposed since 1972 but was shelved in the 1997 roads review. A new bridge was built in Helmsdale in 1972 and major improvements north of there allowed for a new route thought the Ord of Caithness which was completed in 2008.

At Berriedale Braes the road has a steep descent to cross a bridge at the bottom of the valley before steeply rising again to a tight hairpin bend. Works to improve this section were completed in 2021. A similar hairpin layout existed further north at Dunbeath but this was bypassed by a large viaduct in 1989. At Latherton the A9 turns north and terminates at Scrabster Harbour, north of Thurso. Until 1997 it followed the A99 route to Wick & John O Groats.

From the Archive


This article was first published in August 2022. With thanks to Duncan Macknight.

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A two part special of the Scottish Roadscast charting the history of the A9 was released in August 2020. It can be heard below.

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