A woman was killed when she was hit by a road train on the Stuart Highway overnight, NT Police said.

Detective Acting Superintendent Karl Day said in a statement that about 7:30pm Thursday the female pedestrian was hit by the road train, which was travelling south along the Stuart Highway, near Stuart Well, about 90km south of Alice Springs.

“The driver of the vehicle stopped at the scene and contacted police. Emergency services confirmed the woman was deceased upon arrival,” Supt Day said.

Police said a crime scene was declared and the highway was closed in both directions overnight, with delays still expected on Friday morning.

“Major Crash Investigators believe an unknown vehicle was parked on the northbound side of the highway shortly before the crash occurred, with the vehicle fleeing the scene just after the crash,” Supt Day said.

Official data shows 41 people have been killed on Territory roads this year, compared to seven killed in the same period last year.

Police are asking anyone who was travelling along the Stuart Highway south of Alice Springs last night who has dash cam footage to call them on 131 444 (quote reference P24213936), or make an anonymous reports to Crime Stoppers by calling 1800 333 000.