A woman has sustained injuries and a man remains in a critical condition following a single vehicle crash south of Alice Springs on Friday night.

Around 5pm the two were travelling in a vehicle on Luritja Road, 42kms from the Lasseter Highway turn off when for unknown reasons the vehicle left the roadway, rolled three times before coming to rest on the drivers side of the vehicle and off to the side of the road.

Passing motorists stopped to assist and further raised the alarm driving to a nearby station and contacting police and emergency services.

The 20-year-old female driver sustained minor injuries while a 25-year-old male passenger who was thrown from the vehicle, sustained critical head injuries.

The two were transported to the Alice Springs Hospital and the man was later medivaced to Royal Adelaide Hospital where he remains in a critical condition.

Investigations into the circumstances surrounding the cause of the crash continue.