Emergency services were called after a blue BMW 2 series left the road and collided with a barrier on the southbound carriageway around 10.45pm last night (Thursday, January 4).
The driver, a 19-year-old male from Bursledon, needed extricating after suffering life-threatening injuries in the accident.
He was taken by ambulance to Southampton General Hospital but sadly died a short time later.
Crews from Horndean, Waterlooville and Cosham fire stations took part in the rescue operation while the South Central Ambulance Service also sent a crew, officer and Hazardous Area Response Team to the scene.
No other vehicle was involved while the accident, which took place during a period of heavy rainfall, forced the closure of the motorway between junctions 2 and 3 until the early hours.
“His next of kin have been informed and are being supported by specialist officers,” said a spokeswoman for Hampshire Police.
“Officers investigating the exact circumstances are appealing for any witnesses to come forward.
“If you saw what happened or if you saw a blue BMW 2 Series prior to the collision, then please get in touch.”
Anyone with information should call the police on 101 quoting 44180005119 or Crimestoppers anonymously on 0800 555 111.