The first crossing at the site of the bridge was established in the 11th century by Margaret, queen consort of King Malcolm III, who founded a ferry service to transport religious pilgrims from Edinburgh to Dunfermline Abbey and St Andrews. Its creation gave rise to the port towns of Queensferry and North Queensferry, which remain to this day; the passenger ferry service continued without interruption for over 800 years. There were proposals as early as the 1740s for a road crossing at the site, although its viability was only considered after the Forth Bridge was built in 1890.
The importance of the crossing for vehicular traffic was underpinned when the Great Britain road numbering scheme was drawn up in the 1920s. The planners wished the arterial A9 road to be routed across the Forth here, although the unwillingness to have a ferry crossing as part of this route led to the A90 number being assigned instead.
There was more lobbying for a road crossing in the 1920s and 1930s, when the only vehicle crossing was a single passenger and vehicle ferry. Sir William Denny championed the expansion of that service in the 1930s, providing and operating on behalf of the London and North Eastern Railway two additional ferries to supplement the nearby railway bridge. Due to their success, two more ferry boats were added in the 1940s and 1950s, by which time the ferries were making 40,000 crossings annually, carrying 1.5 million passengers and 800,000 vehicles.
With the then newest and nearest bridge spanning the Forth (the Kincardine Bridge, built in 1936) still around 15 miles (24 km) upstream, the upsurge in demand for a road crossing between Edinburgh and Fife prompted the UK Government to establish the Forth Road Bridge Joint Board (FRBJB) by Act of Parliament in 1947 to oversee the implementation of a new bridge to replace the ferry service. The authorities on both sides investigated in 1955, and drew up an alternative scheme for a tunnel beneath the estuary. This was known as the Maunsell Scheme, and was projected to run somewhat closer to the rail bridge than the present road bridge. The scheme was abandoned as too ambitious, and a bridge was built instead.
Under construction in July 1962
The final construction plan was accepted in February 1958 and work began in September of that year. Mott, Hay and Anderson and Freeman Fox and Partners carried out the design work and a joint venture of Sir William Arrol & Co., Cleveland Bridge & Engineering Company and Dorman Long constructed the bridge at a cost of £11.5 million; the total cost of the project including road connections and realignments was £19.5 million. The resident design engineer was John Alexander King Hamilton FRSE (1900–1982).
It was the longest steel suspension bridge in Europe. It used 210,000 tons of concrete, with 9 miles (14 kilometres) of grade-separated dual-carriageway approach roads. Reed and Mallik (known for Reema construction of houses) of Salisbury, Wiltshire, built the approach viaducts.
Twenty-four individual bridges were built for the approach roads. The 4 1⁄2-mile (7.2 km) southern approach road of the A90 began at Cramond Bridge, over the River Almond on the western outskirts of Edinburgh, near Craigiehall. There were two-level interchanges built at Burnshot, Dolphington (B924) and the Echline junction (A904 and B800). At Dalmeny there was a bridge over the railway. The southern approach roads were built by A.M. Carmichael Ltd. The 4 mi (6 km) northern approach road had three two-level junctions at Ferry Toll (for the B980), Admiralty (for Rosyth Dockyard via the A985, and Inverkeithing via the A921) and at Mastertown/Masterton (for what would be the fledgling M90 southern terminus). The Masterton junction was an octopus junction, a variation of a clover-leaf junction, with six bridges and a 600 ft viaduct. There were fifteen bridges built for this approach road. The northern approach road terminated as the A823(M) at a roundabout with the A823 south of Dunfermline, next to Rosyth railway station. The northern approach roads were built by Whatlings Ltd of Glasgow, later bought by Alfred McAlpine.
Seven lives were lost during construction before the bridge was opened by Queen Elizabeth II and the Duke of Edinburgh on 4 September 1964. The ferry service was discontinued as of that date.
The bridge's management was delegated to the FRBJB, and remained so until 2002 when its operation was transferred to a new body with a wider remit, the Forth Estuary Transport Authority.
On 1 December 2010, the bridge was closed for the first time due to heavy snow. After several accidents meant snowploughs were unable to clear the carriageways, the bridge was closed in both directions at 6.40 a.m. and remained closed for several hours.
As part of celebrations of the 50th anniversary of the bridge's operation, artist Kate Downie was commissioned to create a print of the bridge and hold an exhibition of works portraying it.
On 1 June 2015, Amey took over the maintenance and operating of the bridge on behalf of Transport Scotland from the Forth Estuary Transport Authority and are now called the Forth Bridges Unit.
Public Transport Corridor
On 1 February 2018, the bridge became a Public Transport Corridor, with all approach roads in full operation. The bridge was closed between September and mid October 2017 for roadworks before partially reopening for public buses.