Transport thinktank Greengauge 21 has produced what it calls the “most comprehensive” view of how Britain’s railways could look by the middle of the century, following almost a year of research by experts.

The report ‘Beyond HS2’ suggests Scotland’s vision for 2040 should include a new fast line between Inverkeithing and Bridge of Earn, saying it would achieve a 3h 15m journey time from Scotland to London significantly reduce journey times between the Scottish capital and destinations further north.

Major upgrades of the East Coast Main Line between Edinburgh and Newcastle and a similar revamp of the West Coast Main Line are also part of the package.

The report also suggests a new connection from Curriehill to Edinburgh Gateway to open up services between Glasgow, Livingston and Fife.

A new high-speed line from Rutherglen to Carstairs could free up the existing line through Motherwell to help get Glasgow to London journey times down to a target time of three hours and 15 minutes.

And a spur from that route to join the Shotts line could also help to achieve a faster Glasgow Central to Edinburgh rail service.

Commenting on the publication of the report, one of its five co-authors, Greengauge 21 director Jim Steer, said “Britain lacks a long term national railway strategy beyond HS2. We need a plan to put rocket fuel into our economic productivity and today’s report sets out proposals to do so.

“It is vital for the future of the country that no region is left behind, and the national railway strategy needs to reach all parts of the country. To transform productivity across the whole of Britain, we need to transform the connectivity of dozens of cities the length and breadth of the country. Fundamentally, we need to completely re-orientate the railway from a ‘hub-and-spoke’ centred on London to a fully national network.

“What we have published today provides a wealth of new analysis on connectivity strengths and weaknesses across the country. It is often said that rail needs a ‘guiding mind’ and we hope this report will show just what can be achieved by being prepared to think strategically.”