Police said officers were called to the eastbound carriageway of Sheep Plain at about 5.50pm. It involved a blue Jaguar X-Type vehicle and a woman who suffered life-threatening injuries, Sussex Police added. Police said she was taken to the Royal Sussex County Hospital in Brighton, where she remains. Roads Policing Unit officers are investigating and are keen to speak with anyone who witnessed the collision. Anyone with relevant dashcam footage of the vehicle and the woman at the time of the collision of immediately beforehand is also asked to contact the police. Information can be reported to Sussex Police online, via 101, or email collision.appeal@sussex.police.uk and quote serial 1050 of 10/08.