|Part of E15|
|Length:||30.0 mi (48.3 km)|
|Existed:||1964 – present|
|From:||(Until 2016) Inverkeithing near Forth Road Bridge
|To:||Perth (two ends; one east , one at Broxden Junction )|
|Edinburgh, Edinburgh Airport, Forth Road Bridge, Dunfermline, Kinross, Perth|
The M90 is a motorway in Scotland. It runs from Inverkeithing, at the north end of the Forth Road Bridge, to Perth, passing Dunfermline and Kinross on the way. It is the most northerly motorway in the United Kingdom; the northernmost point being a spur into the western suburbs of Perth at Broxden.
The first section of the M90 opened in 1964 to coincide with the opening of the Forth Road Bridge and Masterton junction (Jct2). The next section, Crossgates – Kelty and Cowdenbeath Bypass, opened on 1 December 1969, with the next section, Kinross and Milnathort Bypass, opening in May 1972.
The final two sections were due to begin construction around 1973/74, but due to the oil crisis, were put on hold. The next section from Arlary ( Jct 8 with A91) to Arngask was opened in March 1977, with the final section between Arngask (GlenFarg) and Muirmont opening in August 1980; which connected up with the completed Friarton Bridge and Perth Bypass to Broxden.
The M90's most substantial engineering feature is the Friarton Bridge in Perth, a tall concrete pillared structure which traverses the River Tay. The bridge carries eastbound traffic from Broxden towards Dundee and along the Firth of Tay. The Queensferry Crossing will open as part of the motorway in 2016.
A large part of the northern section of the motorway follows the route of the former railway line linking Perth to Glenfarg, Kinross then onwards to the Forth Bridge. It is not obvious when first driving along the road but close inspection of the 1:25,000 scale Ordnance Survey maps of the route illustrates this.
Near to its northern terminus, the motorway splits into two branches. The construction of this three-way interchange required the removal of about 900,000 cubic metres of material, mostly rock. The motorway bends through more than 90 degrees, on a compound curve partly of 520.8 m and partly of 694.5 m radius. One branch heads in a north-easterly direction, flowing into the A90 at its end, numbered junction 11. (This branch was formerly the M85 motorway, until the A85 was renumbered as A90.) The other branch forms part of the western bypass of Perth, and meets the A9 at its end, numbered junction 12. The gradient is 4.57% uphill and 5.65% downhill on this section. The slip roads forming this branch merge with shared priority to allow HGVs to maintain momentum on the steep upgrade.The Broxden to Muirmont slip road at the centre of the interchange has a radius of 136.4 m, necessitating maximum superelevation of 7%.
The M90 is considered[according to whom?] one of the UK's most sub-standard motorways of significant distance. Junctions 1 and 2 share a tiny common sliproad, forcing a conflict between entering and leaving traffic at the junction with the A823(M). It lacks hard shoulders for an 8-mile (13 km) section. In this section there are emergency lay-bys at 1⁄4-mile (400 m) intervals instead. The M90 here has another of the tightest corners on the UK motorway network, for which some traffic can be forced to slow down. The corner cuts through the northern side of the Ochil Hills and has a curve radius of 694.5 m (a recommended minimum of 914 m was standard practice at the time of construction). This corner also coincides with one of the steepest sections of the motorway, for which north-bound heavy goods vehicles (HGVs) are sign-posted to stay in a low gear and often brake continuously through the turn. South-bound HGVs are normally substantially reduced in speed as they make the incline.
As part of the Queensferry Crossing scheme, the M90 will be extended across the Firth of Forth over a new cable-stayed bridge, connecting to the northern end of the M9 spur at Scotstoun Interchange. The former M9 spur is now part of M90, in preparation for the completion of the crossing.
|Northbound exits||Junction||Southbound exits|
|Glasgow, Inverness, Stirling A9
|J12||Start of motorway|
|Road continues as A90 to Dundee, Aberdeen and Forfar||J11||Perth A85, Inverness A9
|Perth, Crieff A85||Start of motorway|
|Perth, Stirling, Glasgow (A9)||J10||Perth, Stirling, Pitlochry (A9)|
|Bridge of Earn, Aberargie A912||J9||Bridge of Earn, Aberargie A912|
|Cupar, St Andrews A91||J8||No exit|
|No exit||J7||Stirling A91
|Kinross, Milnathort A977
|J6||Kinross, Crook of Devon A977
|Cleish, Crook of Devon B9097||J5||Cleish, Ballingry B9097|
|Kelty, Ballingry A909||J4||Kelty, Lochgelly A909|
|Dunfermline A907||J3||Dunfermline A907, Kirkcaldy, Glenrothes A92|
|Kirkcaldy, Glenrothes A92||J2A||No exit|
|Dunfermline, Rosyth A823 (M)||J2||Dunfermline, Rosyth A823(M)|
|Start of motorway||J1||Inverkeithing A921
Kincardine, Glasgow A985
Kincardine, Glasgow A985
|Road continues as A90 to Edinburgh, M9, M8 to Glasgow, Edinburgh Airport, Livingston and Carlisle|
- MultiMap.com (April 2007). "Map Source".
- RailScot (April 2007). "RailScot".
- M90 J12 Broxden, sabre-roads.org.uk (retrieved 2013-01-16)
- "Scotland gets it first Managed Motorway". 2012-11-27. Retrieved 2013-03-18.
- CBRD Motorway Database - M90
- The Motorway Archive - M90
- Pathetic Motorways - M90