A motorist has been charged over the death of a woman who was discovered lying on a road in northern NSW.

The 43-year-old woman was found unconscious on a road in Narrabri, shortly after 10pm (AEDT) on New Year's Eve.

She was treated for severe head injuries at Narrabri Hospital before being airlifted to Sydney in a critical condition.

The woman died on Wednesday night, police said.

About 2.50pm (AEDT) on Thursday, officers arrested a 41-year-old man at a home in Warialda.

He has been charged with dangerous driving occasioning death and was refused bail to appear at Moree Bail Court later on Friday.