The project would duplicate the highway all the way from Lithgow to Katoomba by 2028, potentially slashing travel times between Bathurst and Sydney.

Deputy Premier John Barilaro joined Bathurst MP Paul Toole to announce that construction of the duplicated highway would first focus on the Medlow Bath upgrade, Mount Victoria bypass and Jenolan Caves Road to South Bowenfels.

Mr Barilaro said the duplication would deliver much improved safety and efficiency, improve freight access and cut travel times and the road toll, while laying the foundations for the transformation of a rapidly growing region.

“The Central West NSW region is the third-largest contributor to the NSW economy and the Great Western Highway is vital to the NSW economy, connecting Sydney with world-class people, produce and resources from Lithgow, Bathurst, Orange, Mudgee, Wellington, Dubbo and beyond," Mr Barilaro said.

“We have worked hard to get the budget back into shape and to strengthen our economy. That hard work is paying off as we are able to deliver these major infrastructure projects for regional communities across NSW."

Mr Barilaro said the announcement followed a promise made in June to undertake investigative work in the project and was part of the government's pitch to the Central West for its vision going forward.

"It's something we do at every election, last election it was the recycling of poles and wires; the windfall of the poles and wires was 30 per cent of the proceeds go to regional NSW to upgrade schools, hospitals, roads and rail," he said. 

"History is a good predictor of the future, today I'm here pitching a vision to the people of the Central West if re-elected a Liberal / National Government will put focus on the Great Western Highway, and today is the right day to make such a significant announcement."