Police are hunting a man who indecently assaulted a 40-year-old woman who was found "dishevelled" and with some of her clothes missing.
The assault happened as the woman was walking near the A590 Dalton-in-Furness bypass at about midnight on Saturday.
Cumbria Police said the driver picked the woman up near Askam-in-Furness.
They want to trace a driver who gave the victim a lift home after she was attacked but said he was not a suspect.
The victim was wearing a multi-coloured fleece.
Police said she was dropped off by a taxi earlier in the evening in a lay-by near Dalton Park Zoo.