POLICE are appealing for witnesses following a fatal crash on the A3 last night.
A white Vauxhall Corsa had left the carriageway and came to rest on its roof on the nearside verge.
The driver, a 22-year-old woman from Waterlooville, was pronounced dead at the scene.
Investigations into the circumstances surrounding the accident are ongoing and officers are appealing for witnesses to come forward.
The driver of a black Ford Focus, a 26-year-old man from Portsmouth, has been arrested on suspicion of causing death by careless driving and driving under the influence of drugs.
There is no evidence to suggest at this stage that the two vehicles were in collision with each other, the spokesman added.
Anyone with information about this incident or having seen either of these vehicles earlier in the evening are asked to call the police on on 101, quoting 44160349433, or Crimestoppers anonymously on 0800 555111.