A Roads and Maritime Services spokesperson said controlled open cut blasting will be used to break through hard rock south of Macksville as part of the $830 million project.

“Blasting will be carried out at four locations between Donnellyville and Macksville to remove about 40,000 cubic metres of rock,” the spokesperson said.

“The rock will be crushed and reused elsewhere along the project where high quality material is needed."

Blasting will start on Thursday July 2, weather permitting and be carried out between 1pm and 2pm.

“There will be around 100 blasts at four locations during this time until March next year, with the second blast planned for Monday," the spokesperson said.

“Residents will be notified before each controlled blast and electronic message signs will advise motorists in advance of blasting dates and times.

“Motorists can expect delays of up to 15 minutes on the Pacific Highway and on local roads during the controlled blasts with traffic control in place for motorists’ safety.”

The Warrrell Creek to Nambucca Heads upgrade will deliver 20 kilometres of four lane divided highway and is due for completion in 2017.