A woman who was found injured by the side of the M3 in Surrey with serious head injuries has died in hospital.
Violet Johnson, 46, of Chertsey Bridge Road, Chertsey, was found unconscious on the hard shoulder between junctions one and two on Monday.
Surrey Police said Ms Johnson died at St George's Hospital in Tooting, south London, on Thursday.
A post-mortem examination will be carried out at a date yet to be arranged.
Officers are investigating how the woman came to be on the hard shoulder but said there was no indication of third party involvement.
A police spokesman said they were treating the incident as unexplained.
Det Insp Paul Burrill said he wanted to hear from any motorists on the M3 or near the Littleton Lane Bridge who had seen anything unusual.