A tunnel to Orkney
Orkney lies less than 10 miles north of the Scottish mainland, a distance short enough to prompt many islanders to wonder if a bridge or tunnel could ever join the two.
In 2005, the islands’ local authority investigated whether a fixed link was possible. Research suggested a sub-sea tunnel between South Ronaldsay in Orkney and a point close to John o’ Groats would cost at least £150 million.
Highland councillor John Green said at the time: “When you consider that around £11 million a year in subsidy goes into the Pentland Firth ferry - it wouldn’t take long to recoup that by building a tunnel.”
Numerous tunnels covering similar distances underwater have been built in Norway, which provided inspiration to Orkney councillors.
But there are no signs the project will become a reality anytime soon.
The Bennie railplane
Scottish engineer George Bennie was a proponent of high-speed rail decades before it became mainstream government policy.
He built a prototype system known as a ‘railplane’ - a propeller-driven carriage suspended from a monorail - with a view to revolutionising commuter transport.
The railplane was designed to travel above conventional railways, seperating slower goods trains and faster passenger services.
Bennie invited guests to try out his test track built over a stretch of LNER railway at Milngavie, near Glasgow.
On July 8, 1930, journalists and VIPs were taken for rides in a special railplane carriage. Despite the event’s success, progress on the project remained slow.
Although Bennie claimed his invention could reach speeds of 120mph - just 6mph slower than the record-breaking Mallard steam engine - the railplane could only muster speeds of 50mph due to the short length of track - 426ft.
By 1937 Bennie had spent all his money travelling the world in a bid to gain backing for his invention, bankrupting himself in the process.
The prototype track stood in Milngavie until it was eventually demolished in 1957.
The Strathclyde tram project
Glasgow once had the most comprehensive tram network of any UK city outside London. Its closure in 1962 proved unpopular and by 1994 transport chiefs were drawing up plans to revive at least part of the system.
Strathclyde Passenger Transport Authority (SPTA) proposed building an initial 12-mile light rail route from Maryhill in the north of the city, through the centre and out as far as Easterhouse.
Promotional materials were published and the public seemed onside. But there were objections.
Recently privatised bus operators were firmly opposed, and a public enquiry was called in 1996.
Four parliamentary commissioners heard evidence for nine weeks and eventually ruled against the scheme.
Controversially, SPTA was offered no right of appeal and the commissioners were not obliged to make their findings public.
SPTA’s then chairman, councillor Charlie Gordon, said Glasgow had “missed out on the chance of a twenty-first century mode of transport which had the overwhelming and enthusiastic support of the public.”
Now landing at Falkirk international airport
Central Scotland once had an airport to rival those at Turnhouse in Edinburgh and Renfrew near Glasgow. Opened in July 1939, the airfield at Grangemouth was intended to offer both commercial flights and a home to the RAF.
But the outbreak of war saw it become a hub of military activity before closing to all traffic in 1955.
Plans to build a new airport in or around Falkirk have surfaced several times in the decades since.
In the early 1970s, a site near the semi-rural village of Slamannan, four miles south of the town, was identified as suitable for such a scheme.
The plans were temporarily revived in 2002 by local councillor Dennis Goldie. “It’s a perfect spot,” he said at the time. “There’s lots of flat land and, if the proper infrastructure was put in place, would be an ideal place for a new airport.”
High-speed rail between Edinburgh and Glasgow
Plans to link London and Birmingham via a new dedicated high-speed rail service were gathering momentum in 2012.
It was with that in mind Scottish ministers made a tenative announcement in favour of a similar service between Glasgow and Edinburgh.
Then deputy first minister Nicola Sturgeon said the Scottish government would “not wait” for Westminster to deliver a cross-border high-speed line.
She said Scotland would be “firing ahead” with its own plans and aimed to deliver the scheme by 2024.
But in January this year transport minister Derek Mackay announced it was “not possible to progress planning” until a cross-border link with England was identified.
While commitments have been made to improve journey times between Scotland and England, genuine high-speed rail north of the border remains in the sidings - for now at least.