Passing motorists acted quickly and bravely to save two of the people from the burning wreckage.

Police said they used their own car to try and push the damaged car over and managed to free two of the people in the car.

The crash happened after the car rolled about 40km south of Katherine on the Stuart Highway about 11.30pm.

Emergency service crews attended however, the person had already died at the scene.

Emergency services arrived to transport the injured pair, a man and a woman aged about 50 and both from Katherine, to Katherine Hospital for medical treatment.

Major Crash Investigation Unit arrived on scene this morning to determine the circumstances of the crash.

Traffic diversions have been in place for most of the day.

Detective Senior Sergeant Brendan Lindner said it has been an overwhelming week on NT roads.

"We have had multiple crashes across the Northern Territory this week, resulting in many serious injuries and now a death," Sen.-Sgt Lindner said.

"This death was avoidable.

"The actions of those who stopped to assist, placing themselves at considerable risk, are highly commendable and I thank them.

"From a police perspective, it's disappointing to see dangerous behaviour such as drink driving that has led to many of these crashes.

"There has been an influx of road users due to the borders opening.

"We urge people to be safe when travelling on the road, particularly major routes like the Stuart Highway.

"Drive to the conditions and do not drive after drinking. Wear your seatbelt, avoid distractions and stop for a break if you're feeling tired."

It has been a particularly bad week on local roads after a car collided with a road train north of Katherine, at the Edith River bridge, in the early hours of Wednesday.

A 29-year-old woman and a 24-year-old man travelling in a Corolla suffered injuries and were airlifted to Royal Darwin Hospital.

The woman was admitted in a serious condition, while the man's injuries were said to be more serious.

The driver of the road train was not injured.

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