A CAR swerved and crashed into the central reservation on the motorway, police said.
The 19-year-old driver, a woman from Fareham, suffered minor injuries in the crash.
It comes after two cars were involved in an incident in lane three of the M27 at Fareham, between junctions 11 and 12.
One of the cars, a blue Vauxhall Agila, crashed into the central reservation but the other, a black estate, left the scene.
Police said it is thought the car was a Vauxhall Astra.
It happened on Saturday at 12.40pm.
PC Anthony Botten said: ‘I am appealing to anyone who witnessed this collision to make contact with me immediately so we can ascertain what took place.
‘I would also urge motorists to check any DashCam footage to see whether they have caught the collision or anything immediately prior to it that could help in identifying the unknown vehicle.’
Anyone with information is asked to contact PC Botten on 101, quoting 44170111475, or call the charity Crimestoppers anonymously on 0800 555 111.