Highlands residents could soon have a shorter commute to Canberra and Sydney.
Minister for transport and infrastructure Andrew Constance announced an initial $80 million investment on the Canberra to Sydney route on Sunday, as a part of a $295 million investment in a fast rail network.
This will include preliminary work on a new straightened route to "a high speed standard" between Menangle and Yerrinbool.
The works will see Goulburn and other regions such as Nowra, Newcastle and the Central West connected on a fast rail network with Sydney.
Mr Constance said there would be a replacement of the XPT, Endeavour and Explorer fleets as a part of the project.
"We're going for shorter-style, new regional trains. At the same time we're moving to a regional links service, which is going to have a profound impact in terms of getting people on board," he said.
"These are world-class, modern-day trains. The XPT fleet is starting to head towards around 40 years in age, they're really past their shelf life in that sense."
While Mr Constance did not give an estimated timeframe for completion, he said the Liberal and National government was committed to start work in the next term of government.
"The transport bureaucracy is already working on it. Transport for NSW will work with our train operators in terms of NSW trains and Sydney trains and just get on with it," he said.
"We've done a lot of assessment work already on this line. There are constraints but sometimes just doing simple things can have a profound impact."
Southern Tablelands Rail Users Group president Greg Price said while the group welcomed the announcement, more needed to be done to reduce travel time.
"The announcement to upgrade the tracks is long overdue but Southern Tablelands Rail Users Group is very disappointed that the government didn't have the vision to specify tilt trains in the new contract for the new diesel trains, which would've provided journey reduction times for everyone in regional NSW," he said.
"Track upgrading will take many years and the provision of tilt trains in the new diesel train contract would've provided immediate journey time reduction, which could've been further reduced with the straightening of the lines in future years."
The state government is taking advice from strategic technical adviser Professor Andrew McNaughton on the best way forward for the project.
"One of the things we're taking advice from Professor McNaughton on is how we can achieve it. I want to see a sub three hour journey time between Canberra and Sydney," he said.
"As part of that we also have in the background the fact that one day given our population growth we will see a VFT [Very Fast Train] style equivalent train.
"In the meantime we can start to look at our existing rail corridors and speed the trains up, that's where it's really important."
Mr Constance said the funding was a part of a 10-year capital works project and due to the "strong economic management of the NSW Liberals and Nationals government".