The federal budget will contain funding for a major upgrade and duplication of Athllon Drive.
The government will also allocate $2.8 million for an intersection upgrade at Kent Street and Novar Street.
The ACT government revealed the the concept designs for the duplication of Athllon Drive in mid-2020.
The concept design proposed to duplicate a 600m stretch of road between Shea Street and Melrose Drive in Phillip and a 2.4km stretch between Sulwood Drive and Drakeford Drive in Kambah.
The designs included new traffic lights installed at Melrose Drive, Parramatta St and Atkins St.
Part time traffic signals have also been proposed at the Sulwood Drive roundabout.
A priority bus lane northbound has also been proposed, which ACT Roads Minister Chris Steel Mr Steel said at the time would cut two minutes off travel times for commuters on the R4 and R5 buses.
There would also be changes to bus stops, with one southbound stop proposed to replace two currently on that section of road.
A four-way intersection has been included at Shea St to provide access to proposed development blocks in the area.
The ACT government says the proposed extension of light rail to Mawson means the detailed design has not yet been done.
A tender for detailed design of the southern section is expected to be released by the middle of this year.
ACT Liberal senator Zed Seselja said thousands of commuters use Athllon Drive everyday and the $46.7 million upgrade would help ease congestion.
"This funding comes on top of more than $2.1 billion in infrastructure commitments by the Liberal National government in the ACT in recent years, the largest investment in Canberra in a generation," Senator Seselja said.
It will also contribute to planning work for the Canberra Corridor.
Treasurer Josh Frydenberg outlined infrastructure as a key pillar to economy growth beyond COVID-19.
"By enhancing transport connectivity, we're strengthening our supply chains against challenges such as COVID-related disruptions and the impact of natural disasters," he said.
"This gives businesses and consumers the confidence and certainty they need in uncertain times."
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