The time has come for Australia to let go of its fast-train dream and instead aspire to rail services that are merely 'fast-ish', a rail expert says.

Key points: Some rail commuters just 100km away from Brisbane leave home, and arrive home, in the dark

Some rail commuters just 100km away from Brisbane leave home, and arrive home, in the dark A rail expert says commuters are more likely to travel by trains when the speed is faster than buses or cars

A rail expert says commuters are more likely to travel by trains when the speed is faster than buses or cars Federal LNP MP Ted O'Brien says faster trains are needed across south-east Queensland due to the region's expected population growth

Associate Professor Phillip Laird from the University of Wollongong said Australia did not have the population density to justify the enormous cost of a true fast train, which can reach 250kph.

However, he said medium-speed trains — which could travel around 150kph — were comparatively easy to build.

He said such transport had the capacity to have a positive impact on more than just commuters, as has been the case in regional Victoria and Western Australia.

"This has been demonstrated in Victoria with regional fast trial trains doing 160kph on upgraded tracks," Professor Laird said.

"Ballarat and Bendigo and Geelong have had a real boost in population growth and business activity and tourism.

"When you get trains that are averaging 100kph or even 85kph as you get in Perth to Mandurah, going faster than cars or buses, people will use them.

"If it's there as a commuting option, they'll make decisions to buy a house in a regional city as opposed to the fringes of a big city."

A Queensland Rail electrical, multiple-unit train arrives at Roma Street Train Station. ( Supplied: Bombardier Transport )

Long commutes a way of life

Sunshine Coast resident Dave Rudland said that sort of train service would make a big difference to his life.

For the past 13 years, he has spent five hours of every work day commuting to his job in Brisbane.

He gets up in the dark, gets home in the dark.

"You become very regimented," he said.

"You've got to be in the right place at the right time.

"You try and make the best of it, whether it be getting to know the train drivers, the station masters and making the most of an inevitable situation."

Mr Rudland says his five-hour, return train journey to Brisbane now takes longer. ( ABC Sunshine Coast: Alex Easton )

Mr Rudland said the trip also took longer than it used to.

"With the addition of the Petrie line, it's not an express [service] as it used to be, it's probably added about 25 minutes in each direction.

"It's added to the congestion as well," he said.

"Often you'll get on at the city stations and beyond [the inner city] all the seats will be occupied, so it's making it a busier trip as well."'

Upgrade 'long overdue': Professor

Sunshine Coast Federal MP Ted O'Brien has been pushing for what he called the North Coast Connect project.

Mr O'Brien said the project would include a new line to Maroochydore and a train line between Brisbane and Nambour which would allow for speeds between 140kph to 210kph "depends on the engineering solution that you arrive at".

The current average speed on the line between the Sunshine Coast and the state's capital is about 55kph.

"The key difference between the existing rail and the proposed fast rail really comes down to speed, because that's what makes a big difference to the passengers," Mr O'Brien said.

"Sometimes it can take well over two hours to get to Brisbane from the Sunny Coast, it should be taking half that time, if not faster."

The business case on the upgrade is due early next year.

Professor Laird said the Sunshine Coast line was "long overdue" for an upgrade to medium-speed trains.

He said much of the planning and land acquisitions, to make way for a duplication of the line, had already been done.

"What's there at the moment isn't good enough.

"Between Nambour and Beerburrum, it's the most congested single piece of railway track in Australia — long overdue for duplication on an improved alignment."

When there is track damage on the Sunshine Coast line, it causes major disruptions for commuters. ( Supplied: Queensland Rail )

However, Mr O'Brien said it was not that simple.

"If you're going to have a train going three times the speed, you've got to make sure that the track is straight enough otherwise the train will fall off," he said.

"You can imagine the amount of engineering that goes into doing a proper business case for that."

Faster trains warranted in regions

Nonetheless, Mr O'Brien said the need for faster trains across south-east Queensland was warranted not just between Brisbane and the Sunshine Coast, but also between the state's capital and the Gold Coast, Ipswich and Toowoomba.

Mr O'Brien says due to population growth, faster train services are needed throughout south-east Queensland. ( ABC Gold Coast: Damien Larkins )

"We know south-east Queensland is growing at such a pace that our collective challenge ... is to ensure that infrastructure keeps ahead of the population curve," he says.

"We are only going to have one crack at this really because we've got to learn the lessons from Melbourne and Sydney.

"We are going to grow quickly and large. We either plan ahead and invest in the infrastructure, or we don't.

Is fast rail still a pipe dream for the Sunshine Coast? ( Queensland Rail: www.queenslandrail.com.au )

"We have to be looking 20, 30 years ahead and saying, 'How do we want south-east Queensland to connect? And if it's not through an integrated rail system than what is it?'.

"I believe there is no better solution than fast rail and we should be looking at this from a broader south-east Queensland point of view."

Cynicism after years of promises

The Federal Government plans to spend $2 billion for fast train services between Melbourne and Geelong. ( ABC News: Paul Sellenger )

New South Wales and Victoria have been assessing better regional-city connectivity with studies on true fast rail underway since late last year.

While those studies were more ambitious than Mr O'Brien's plan, Dave Rudland said he was not holding his breath for either anytime soon.

"There is that overriding cynicism I think that most communities have after years and years of promises.

He said ultimately an outcome was not determined by speed — but money.

"Where's the funding coming from and a specific timetable that we can we can take some faith in and trust?"