Travel times between Sydney and regional centres in NSW could be slashed by up to 75 per cent under a new fast rail plan.

It’s not the first time high-speed rail plans have been promised before a state election, but Premier Gladys Berejiklian has insisted the announcement on Tuesday is not a stunt in the lead up to the March poll.

Four potential routes have already been identified, connecting north to Port Macquarie via Taree, Newcastle and the Central Coast.

The southern route could reach Canberra and Goulburn, while the western line could connect to Orange or Parkes via Bathurst and Lithgow.

A southern coastal route could travel to Nowra and Wollongong.

The government would first optimise current tracks to get travel speeds to at least 200km/h, before building a dedicated fast rail line that reaches 250km/h or potentially 350km/h.

No Australian passenger train has ever exceeded 215km/h, and the top speed of most lines is 160km/h.

Ms Berejiklian said it would cut some travel times by up to 75 per cent, while the trip to Canberra could be cut from three hours to one.

The four potential routes identified by the government. Photo: NSW government

The journey to Goulburn could take just 30 minutes.

It would be Port Macquarie’s first direct train line if the northern route is delivered as marketed. The nearest station currently is in Wauchope, and about a seven-hour journey from Sydney’s Central Station by today’s train line.

British rail infrastructure expert Andrew McNaughton has been appointed to advise the government on the most appropriate routes, train speeds and station locations.

Professor McNaughton, who has worked on high-speed rail in the United Kingdom, said he would look for the most practical option instead of the flashiest or fastest.

“If you make it the Concorde for the rich, you’ve defeated the whole purpose of doing it,” he said.

“Whether you are the richest or poorest in the state you have one thing in common – how much time you have.”

Ms Berejiklian said the plan was different to previous fast rail promises on the east coast because it was not looking at connecting Melbourne or Brisbane.

“This isn’t something we’ve just come up with now. We’ve been working on this for a long time,” Ms Berejiklian told reporters on Tuesday.

“This is a social issue, not just an economic issue.

“It’s about giving our citizens choice about how they live, where they live and how they can be better connected.”

Infrastructure Australia in 2013 found a national fast rail project would cost $114 billion.

“I’m not going to wait for other states and the federal government – we’ve waited for too long,” Ms Berejiklian said.

“NSW will start the process.”

Ms Berejiklian, Professor Andrew McNaughton and Transport Minister Andrew Constance on Tuesday. Photo: AAP

She has committed $4.6 million to develop a plan, but it remains uncertain how much the whole project would cost.

“We need to see what we’re dealing with in this first stage before we talk about that,” the Premier said.

“Let’s make those decisions at that point.”

Construction would start by 2023 if the state Coalition is re-elected, with an eye on upgrading existing corridors and fleet before building dedicated high-speed rail lines.

“In the immediate future, faster rail would see upgrades along existing rail alignments and provide services of at least 200km/h, slashing travel times by one third,” Transport Minister Andrew Constance said in a statement on Tuesday.

“Ultimately, in the long term, high-speed rail would see the development of new alignments and lines, providing speeds of over 250km/h, with examples overseas travelling up to 350km/h and higher – giving the potential to cut travel times by up to 75 per cent.”

-with AAP