|Location Map ( geo)|
|Via:||South Queensferry, Inverkeithing|
|Distance:||28.7 miles (46.2 km)|
|Meets:||M9, A90, A823(M), A92(M), A92, A91, A93, A9, A85, A90|
|Former Number(s):||M85, M9|
|Route outline (key)|
The M90 is a link between the M9 near Kirkliston and Perth, acting as the main road between Edinburgh and northern Scotland. It is the northernmost motorway in the UK, and Craigend Interchange south of Perth is the northernmost complex interchange.
For over 50 years the M90 was confined to the north side of the Firth of Forth, beginning less than two miles north of the Forth Road Bridge. In recent years the FRB has been supplanted by the new Queensferry Crossing, which took the M90 designation along with the reconfigured approach road to the north. The M9 spur to the south also became part of the M90. This means the M90 is now continuous from the Edinburgh end of the M9 to Perth, with the exception of a non-motorway (but nevertheless Special Road) gap just south of the Crossing which encompasses almost all of the new southern approach road.
The spur from Craigend to the eastern side of Perth originally held the number M85, however when this section of A85 was renumbered as part of the A90 in 1994, this spur became part of the M90, creating an interchange where motorways meeting in three directions are all numbered M90.
A section of M90 less than 2 miles long, and its even shorter spur the A823(M), were the first motorways in Scotland, opening simultaneously with the non-motorway Forth Road Bridge in September 1964. The decision to make them motorways appears to have been taken at a late stage.
The Kinross bypass, which opened in December 1971, was the first motorway to be built using an unreinforced concrete surface. Resurfacing work of the whole 8 mile section was completed in December 2017 having been worked on progressively for the past decade. Through this section there is no hard shoulder but frequent lay-bys, some equipped with emergency telephones.
Most of the sections in which the M90 was built ended at temporary termini rather than permanent junctions. The first four sections in historical order were also the four southernmost in geographical order (not counting the much later southward extension), and the first three were built without hard shoulders. The first two have since had hard shoulders added; this may yet happen to the third.
Forth Replacement Crossing
M90 Southern Extension
The M90 was extended southwards, in 2017, across the Firth of Forth via a new cable-stayed bridge as part of the Forth Replacement Crossing project. As part of this project the existing A90 dual carriageway north of the Forth between Rosyth and Inverkeithing was upgraded, along with a section south of the Forth near Scotstoun Interchange (though this did not become motorway). The former M9 Spur also become part of the M90.
Intelligent Transport System
Phase 1 of the Forth Replacement Crossing project involved the upgrading of the M90 motorway between Healbeath Junction (J3) and Admiralty (J1). The existing southbound hard shoulder was adapted for use as a bus lane and overhead gantries were installed. These new gantries carry variable message signs which include the ability to set variable mandatory speed limits - an Intelligent Transport System (ITS). This is the first use of variable mandatory speed limits in Scotland. The new ITS was activated on 4th December 2012. Some of the new gantries carry speed cameras which are used to enforce the variable speed limits.
M9 Junction 1A Upgrade
Previously the M9 Junction 1A only had east-facing slip roads. As part of the Forth Replacement Crossing project this junction was upgraded with new west-facing slip roads, opening on 1st February 2013. The east facing slip roads were also widened to return them to their original 2 lane width. (They were narrowed to a single lane previously for safely reasons). The southbound hard shoulder was also upgraded so it can be used as a bus lane, and an ITS system with variable mandatory speed limits was installed.
The Broxden Roundabout is the northernmost motorway junction in the Great Britain. Found in Perth, it is one of Scotland's busiest and most important junctions. The A9 heads north for its journey to Inverness & the far north of Scotland at this roundabout, whilst southbound the A9 is signed for Stirling and Glasgow and the A93 takes the A9's old route though Perth. The M90 spur meanwhile takes traffic to Dundee, Aberdeen or Edinburgh.
Kinross services are the most northerly services in Great Britain, being located just off junction 6 of the M90. As befits a relatively quiet motorway, it is a very small single-site MSA.
|Kirkliston Spur||25th November 1970 (Originally numbered M9)|
|Kirkliston to A90||September 2007|
|Queensferry Crossing||4th September 2017|
|Forth Road Bridge North Approaches||4th September 1964|
|Crossgates & Kelty bypass||1st December 1969|
|Kinross & Milnathort Bypass||13th December 1971|
|Arlary to Arngask||1st March 1977|
|Arngask to Bridge of Earn||3rd October 1980|
|Bridge of Earn to Craigend||18th October 1977|
|Craigend to Broxden||May 1978|
|Friarton Bridge||28th September 1978 (Originally numbered M85)|