The horror smash occurred when a Mitsubishi van and a Toyota Prado carrying a family of seven collided on the Pacific Highway south of Port Macquarie just before 11am on Thursday.

The van driver, 20, from Britain, has been charged with negligent driving causing death and not giving way.

He has been granted conditional bail and will appear in Port Macquarie Local Court on Friday.

Police allege he pulled out from the verge of the Pacific Highway and started to head north.

Police said it appeared the vehicle carrying the family swerved and rolled several times. A 16-year-old girl, who was a passenger in the Prado, was thrown from the vehicle and died at the scene.

The driver of the Prado, a 37-year-old woman, and a nine-year-old girl suffered fractures and were flown to John Hunter Hospital in Newcastle where they are in a stable condition.

The remaining family members, a 40-year-old woman, a 20-year-old man and two boys, aged 15 and six, were taken to Port Macquarie Base Hospital as a precaution.

The driver of the van was treated at Port Macquarie Base Hospital where he underwent mandatory testing.

His passenger, another 20-year-old man, did not require medical treatment.

Friends of the dead girl have flooded social media with tributes, describing her as "gorgeous and bubbly" and an "angel".

Police are urging road users to take care and slow down over the long weekend.

Double demerits will be in place over the entire long weekend for all speeding, mobile phone, seatbelt and motorcycle-helmet offences.