Bottleneck 'gone for good': when you'll be able to drive the new M1 upgrade

One of the Hunter's most desperately needed road projects will open to traffic in the early hours of Friday, finally bypassing a bottleneck that has snarled the region for generations.

The Hexam-Heatherbrae bottleneck has been declared "gone for good" as the $2.24 billion M1 Pacific Motorway extension between Black Hill and Raymond Terrace welcomes rolling tyres in less than 48 hours.

The project, jointly funded by the federal and state governments, delivers the last link in the Sydney-to-Brisbane motorway corridor.

Motorists will be able to drive from Melbourne to Coffs Harbour without hitting a traffic light or roundabout.

For daily commuters, the government says the extension will cut peak-hour travel by seven to nine minutes, and take up to 25,000 vehicles a day from local streets in Hexham, Heatherbrae, Tarro and Thornton.

For freight operators, it removes one of the most persistent choke points on the east coast supply chain.

The extension was officially opened by Prime Minister Anthony Albanese, who was joined by the federal Minister for Infrastructure, Transport and Regional Development, Catherine King, and local MPs.

"My government is delivering a faster, safer connection through the Hunter and invested almost $1.8 billion in this project," Mr Albanese said.

"This is what investing in infrastructure is all about. We're cutting travel times, getting trucks and freight moving, and building for the future."

Mr Albanese told the crowd that the issue was personal.

He said that a young cousin, who he was named after, had died on the highway in the early 1960s, before he was born, and that the tragedy had shaped his determination to upgrade the corridor.

Ms King said the project, first committed to in 2019 with construction beginning in 2023, had been delivered about a year and a half ahead of an original 2028 completion date.

"The days of holiday traffic crawling through the Hunter are over, with our new bypass of Hexham and Heatherbrae now delivered," Ms King said.

"We planned to open this project in 2028, they got it done one and a half years early."

NSW Minister for Roads Jenny Aitchison linked the opening to a much longer history, noting the road between Hexham and Tweed Heads was first proclaimed a state highway in 1928, and that route assessments for the current extension dated to 2004.

She pointed to the twin bus tragedies on the old Pacific Highway in 1989, at Cowper, near Grafton, and Clybucca, near Kempsey, which together killed 56 people, as a catalyst for the decades-long push to duplicate and upgrade the highway.

"Almost 950,000 people are expected to call the Hunter home by 2041, and our roads have a vital role to play in how the region functions," Ms Aitchison said.

"The M1 extension reflects the needs of a region that is working harder, building faster and more ambitious than ever."

Federal Member for Paterson Meryl Swanson, who has represented the electorate through most of the project's life, said the road had been "the next promise, never the next project" for years, before funding was locked in.

"It's been coming for around 20 years, and we've all been working towards this day," Ms Swanson said.

"Not only on budget, but over 12 months early, when do you hear that, especially in construction, in the last few years? We've done it."

State Member for Port Stephens Kate Washington, whose electorate has carried the brunt of the Hexham bottleneck, was more direct.

"Woo hoo! The Hexham bottleneck is gone for good," Ms Washington said.

"This is a great day for the people of Port Stephens, who have been looking forward to this day for decades. Many locals travel on this stretch daily, so it's going to make a massive difference to their lives."

More than 2700 workers helped build the extension, clocking up more than four million hours on site, with 70 per cent of the workforce drawn from the Hunter region and 99 apprentices and trainees trained on the job.

The scale of construction includes more than 1.6 million cubic metres of earth moved, more than 720,000 tonnes of imported rock, 11 bridges supported by 278 piles and 863 girders, and more than 520 kilometres of drainage installed.

The project diverted 96 per cent of construction waste from landfill and installed 435 habitat structures for native wildlife.

Rubber will hit the road early on Friday morning, September 11.