A group pushing for the idea to connect the third-deepest natural harbour in the Southern Hemisphere at Eden on the NSW far south coast to the nation's capital hopes a change of state government may see it become a reality.

The Cooma Monaro Progress Association has made a submission to the draft South East and Tablelands Regional Transportation Plan outlining its concept of the line, despite a state-government-funded feasibility study in 2020 found the cost benefits of the line were negligible.

The association's Richard Hopkins said the line from Canberra to Eden via Bombala should be part of the new 20-year plan.

"It would transfer exports from the inland of NSW to the port of Eden and it would enable the transfer of growth in the capital to the regions, therefore relieving pressure on Canberra and greatly increasing the prospects of people in the Monaro,' he said.

Mr Hopkins doubted the accuracy of the past feasibility study, and claimed the existing line from Canberra to Bombala could be easily refurbished, with a new line built down the escarpment to the coastline.

"The feasibility study arranged by the government through consultants confirmed that the railway is physically possible," he said.

"We have done a lot of work on the economic feasibility, but we do not have a document that conclusively proves it.

"But, we are very confident that an economic assessment will show that it is economically feasible."

Senior lecturer in transport and logistics management at Sydney University Geoffrey Clifton said the proposal should be put on the table in case public funding became available in the future.

Dr Clifton said, while a cost-to-benefit analysis of new rail proposals usually showed there were more short-term benefits to improving the road network, "rail is certainly part of the mix of future transport" in Australia.

"We know that rail has environmental benefits over road as it is able to move big quantities of goods quicker and safer than roads.

"Overseas we are seeing a lot of investment back into the rail network and I think Australia will follow along with that over the next decade, especially as concerns over the environment grow."

NSW Transport Minister Jenny Aitchison said her department was looking at the submissions to the draft plan, including one from the association.

"That's our priority at the moment, to look at these things across the whole strategic area," she said.

"We do want to move to a position where the government is looking at all sources of information and how we move people and freight, rather than just focusing on one or two projects."

Ms Aitchison said one of the biggest frustrations she had heard from residents was their confusion around how decisions were made on projects after proposals were put to them by local government and community groups.

Ms Aitchison said she would "have a fresh look" at the proposal, and others from the 600 submissions received.

"It may not be a full re-look at the whole project, but I think in light of what everyone else is thinking and what the community wants we have to do that," she said.