Tunnelling complete on $2.2 billion bypass

17 Aug 2025 | Big Rigs

The 160-metre Roberts Hill tunnel is the third and final tunnel of the project. Image: TfNSW

Blasting crews have completed the 160-metre Roberts Hill tunnel, the third and final tunnel on the $2.2 billion Coff Harbour Bypass.

It joins the 320-metre Shephards Lane tunnel and the 410-metre Gatelys Road tunnel.

The Australian Government has committed $1.76 billion and the NSW Government $440 million to this $2.2 billion bypass project, which remains on track to open to traffic by late 2026.

The massive excavation effort for these tunnels saw half a million tonnes of rock removed using 280 tonnes of explosives across 570 controlled blasts.

The Roberts Hill tunnel portal has been designed to complement the natural environment with an exposed architectural rock treatment and landscaping. It will include three bridges over North Boambee Road, and Newports Creek and its tributary, and a five metre high noise wall south of the Roberts Hill southern portal.

An artist’s impression of what the Roberts Hill tunnel will look like once complete. Image: TfNSW

Federal Infrastructure Minister Catherine King said, “This is a massive milestone reached in the Coffs Harbour Bypass, this project will transform this local area and help remove thousands of cars and heavy vehicles from CBD streets.

“This project has been a long-time coming, but it is making good progress and will transform Coffs Harbour once complete.”

NSW Minister for the North Coast Janelle Saffin added, “The breakthrough at Roberts Hill is yet another magnificent milestone for the hundreds of workers delivering the project, and for the people of Coffs Harbour who are looking forward to seeing it complete.”

“As a long-time resident of the NSW North Coast region, I know what a difference this will make to those who call it home.”

With all three tunnels now broken through, work will shift to preparing them for traffic. This includes installing drainage systems and laying road pavement.

Each tunnel will also be fitted with sophisticated mechanical, electrical, fire, safety and electronic signage.

The tunnels will have two traffic lanes and a bicycle lane.

Waterproofing will also cover the entire tunnel tube ceiling and sides with this later installed to increase the lifespan of the tunnel and stop any water making its way onto the road, providing a safer journey for road users travelling through the tunnels.

While waterproofing has started in Gatelys Road Tunnel, it will also be carried out in the two other tunnels and is expected to be completed before the end of 2025.

Once this layer is in place, the last covering of shotcrete is sprayed, with paving, drainage and the mechanical and electrical fit out to follow.

As work continues to complete the three tunnels, new sections of road are being progressively opened as part of the project.

“There are already cars driving on new parts of road around the city and there are more sections opening every month,” said NSW Roads Minister Jenny Aitchison.

Among the most recent was the partial opening of the new Coramba Road Interchange on August 13.

Including two new roundabouts, it will provide local traffic access so the Coffs Harbour bypass project can keep building the new road south of the interchange.

While the new roundabouts are operational, the on and off ramps are still being built, and due to open at a later date.

Once the Coffs Harbour Bypass is complete, it will allow motorists on the Pacific Highway to skip up to 12 sets of traffic lights, expected to cut up to 12 minutes off travel times.