But a report funded by the federal and state governments says the cost of full duplication of the 52-km road can't be justified now or even 20 years' into the future.

Friday's announcement saw the NSW government confirming the Barton Highway will remain at two lanes but will see the addition of more overtaking lanes and intersection upgrades.

NSW Roads Minister Melinda Pavey and Member for Goulburn Pru Goward at Murrumbateman in a "pre-budget announcement" revealed the $50 million was for a "new two-lane carriageway and improved safety", matching $50 million already allocated to the road by the Federal Government. The money will be spent over the next four years, with some work expected to start before Christmas.

Sophie Wade from the Duplicate the Barton Highway Community Action Group said details from the announcement were vague but what was clear was "there is no duplication in this announcement" which would mean the two-lane highway becoming a four-lane highway.

Mrs Wade said it was a piecemeal announcement and the full $100 million should be allocated to creating four lanes at least along what locals call the highly-congested "Mad Mile" between the ACT border and Nanima Road.

"That is crucial. It's getting worse and worse every day and there is no room for error," she said.

Ms Pavey said the Barton Highway was a federal responsibility and the allocation of the money by NSW had been "a big concession".

Eden-Monaro MP Dr Mike Kelly, meanwhile, on Friday also reiterated Labor's promise from the 2016 election that it would duplicate the highway if it achieved power. Dr Kelly said duplication, to him, meant four lanes

"Labor at the federal and state level are firmly committed to the duplication of the Barton Highway at the usual 80-20 split and effectively to get the ball rolling we've budgeted close to $100 million to start the process close to the ACT border and keep marching until the job is done," Dr Kelly said.

Dr Kelly said he was "severely disappointed by the reference to overtaking lanes" in the NSW announcement.

"When what we need is a firm commitment from the State Government to the full duplication, because what happens when that $50 million runs out," Dr Kelly said.

"I agree with them 100 per cent that they've got to get the federal government to make a commitment and stumping up."

NRMA director Kate Lundy welcomed the funding, particularly as research by the NRMA indicated the volume of freight movements along the road would increase by 94 per cent by 2031.

A spokeswoman for the NRMA confirmed more was needed, saying: "The NRMA believes full duplication is the best long-term option to reduce traffic congestion and reduce the risk of crashes, but the addition of dual carriageways is a step in the right direction".

The road is a popular one used by commuters between Yass and Canberra, as well as trucks, and tourists to the region's wineries, with between 8000 and 12,000 vehicles along the road each day.

There were 137 crashes on the Barton Highway between 2009 and 2013 with seven fatalities and 70 injury crashes. The majority of crashes recorded were between Murrumbateman village and the ACT border, representing about 44 per cent of all crashes.

Forty per cent of crashes occur on the weekends, particularly Sunday afternoon, suggesting it's a particular dangerous road for tourists, according to the NRMA.

NRMA Members voted the Barton Highway as the eighth worst road in NSW and the ACT in the Seeing Red on Roads report in 2015.

The Barton Highway Improvement Strategy, funded by the federal and NSW governments and released in January this year, acknowledges that studies around the duplication of the Barton Highway extend back to 1996. The report suggests full duplication - that is, the provision of a four-lane highway - will not be happening any time soon, with the cost put initially at $800 million but probably closer to $1 billion.

"The analysis of key performance data tells us that this investment cannot be justified in the immediate future. Evidence also suggests that duplication is not likely to be required within the 20 year framework of the current strategy," the report read.

On Friday night, a Roads and Maritime Services spokesperson provided this response:

"The NSW Government's $50 million commitment announced today will fund many of the short term priorities identified in the Barton Highway Improvement Strategy," a statement read.

"The strategy, which was published in January 2017, outlines a range of short, medium and long term priorities which will improve the performance of the highway over the next 20 years.

"The work will result in a new two lane-road carriageway constructed on the duplication alignment from south of Gooda Creek Road to Vallencia Drive.

"It will also include the upgrade of the Vallencia Drive and Gooda Creek Road intersections including bus stop facilities.

"There will also be improvements to access and safety for cyclists, pedestrians and horse riders within Murrumbateman village in conjunction with Yass Valley Council."