Transport for NSW says it is working on options for the Mandalong Road upgrade at Morisset before seeking feedback from the community.
In a project update last week, TfNSW said the timing of construction had not been confirmed but the works likely would be rolled out in stages "consistent with available funding".
The NSW and federal governments committed $76 million to the project last year. The upgrade survived recent state and federal reviews of road and rail projects in the investment pipeline.
"You may notice Transport staff and contractors on site in the coming months as we carry out investigations to identify utilities, geotechnical and environmental constraints, traffic data collection, ground feature surveys and other investigations," TfNSW said in its update.
The work is designed to widen Mandalong Road, which links growing Morisset with the M1 Pacific Motorway, and ease congestion at peak periods.
It will also help serve the large Cedar Mill and Trinity Point redevelopments planned for the area.
The NSW Department of Planning and Environment's Hunter Regional Plan 2041 names Morisset and nearby Cooranbong and Wyee as "the largest future growth area in the Central Coast and Hunter".
The Newcastle Herald reported in March, weeks before the state election, that the cost of the upgrade could blow out to as much as $122 million.
Transport for NSW said at the time that it was reviewing the scope of the works to "recommend a way forward".
The March report said Lake Macquarie mayor Kay Fraser, independent MP Greg Piper, federal Hunter MP Dan Repacholi and the developer behind the Cedar Mill tourism and entertainment precinct were critical of a lack of progress on the road upgrade.
Mr Piper said on Monday that he would be "absolutely surprised" if the $76 million covered the entire cost of the project but was confident governments would find more money when required.
"It is more likely to be in the order of what Transport is projecting, close to $100 million," he said.
Mr Piper said the state government had confirmed it had allocated $11 million to relieving traffic congestion at the Speers Point roundabout.