IN centuries past, the idea of change at ancient Birnam Wood was so unthinkable that Shakespeare used it to lull one of his most famous villains into false sense of security.

“Macbeth shall never vanquished be until Great Birnam Wood to high Dunsinane Hill shall come against him,” said an apparition, and little did the King suspect it just might.

These days, it’s the railway that runs past the site of the former Perthshire forest that for many has come to symbolise inertia on a dramatic scale.

In 2008, the First Minister Alex Salmond promised to cut 35 minutes off the train journey between the Central belt and Inverness in four years.

Today, exactly ten years later, campaigners will highlight times have been reduced by an average of just four minutes, and two-thirds of the 118-mile Highland Main Line between Perth and Inverness remains single track.

Meanwhile, over the same decade, work has started on a £3bn upgrade to the A9 that follows the same route.

The government quango Transport Scotland says the current aim is to deliver an average rail service lasting three hours, and a "fastest" of 2hrs 45 mins, by 2025.

Transform Scotland, which campaigns for sustainable transport, says the government should now make doubling and electrification of the Highland Main Line, a key connection for the far north, a top priority in its new Strategic Transport Projects Review.

The gorup's Paul Tetlaw said: "In 2008, Alex Salmond said that within four years the rail journey time would be cut to 2 hrs 45 mins, but a decade later it averages around three and a half hours – yet A9 journeys are getting faster as road dualling.

“The public were told that there would be additional rail passing loops and double-tracking, but all that is being delivered is resignalling of two crossing loops.

“Hourly passenger trains and an average journey time saving of 10 minutes are promised but with no additional track it's highly likely we'll see more delays and cancellations as more trains are squeezed onto the single track railway.”

He said the Borders Railway was a reminder single track sections meant poor performance.

He said: “The Scottish Government now needs to deliver serious investment in the railway to ensure there is a level playing field between road and rail.”

Ian Budd, of Friends of the Far North Line, said: “The Highland Main Line is key to the whole regional rail network. Slow journey times and unreliability between Perth and Inverness have a knock-on impact on connecting trains to the Far North Line, Kyle and Elgin, and discourage people from switching from car to train.

“Rail travellers are entitled to see the Scottish Government deliver on its manifesto promises and make the step-change improvements which Alex Salmond announced 10 years ago.

“What we have at the moment in no way equates with the government's stated policy."

David Spaven, from the Rail Freight Group, added: ‘Everyone wants to see fewer 44-tonne trucks on the A9, but the current very limited upgrade to the Highland Main Line offers little or nothing for rail freight.

“Indeed the worry is that rather than freight shifting from road to rail - the Government’s policy objective - we will see the loss of existing rail traffics, as the A9 gets faster and the single-track railway increasingly congested. That’s economic and environmental madness.

“We need longer crossing loops, so that freight trains 40 per cent longer than at present can compete much more effectively with road hauliers.”

The Scottish Government said Phase 1 of the Highland Main Line improvements, increasing services from 9 to 11 per day and shaving six minutes off average trips, had been delivered.

However UK cuts meant spending was restrained.

A spokeswoman said: “Phase 2 is well underway and aims to deliver an hourly service between Inverness and Perth (continuing to Glasgow or Edinburgh), further journey time reductions of around 10 minutes, and more efficient freight operations by Spring 2019.”

“Our ongoing future investment is truly transforming the rail network and giving passengers and freight users across rural and urban Scotland the best railway they’ve ever had.”

She blamed the UK Government for a shortfall in funding for 2019-2024 of "at least £460 million short of early industry estimates of costs to deliver the improvements required to meet forecast future demand for services. This means our future investment decisions will need to reflect the financial climate we are faced with as a consequence of decisions taken by the UK Government.”