A lorry driver whose vehicle and a van had come to an abrupt halt at The Lampool roundabout, Maresfield, near Uckfield, sustained life-threatening head injuries after he left his cab and was struck by a car.
The incident happened at 6.15am on Tuesday (5 November) and led to roads feeding into the roundabout, including the A22, being closed to traffic.
The Kent, Surrey and Sussex air ambulance flew in to assist land-based paramedics called to the scene. The casualty, a 51-year-old man from Uckfield, was taken to the Royal Sussex County Hospital, Brighton.
The vehicles involved were a blue Mercedes-Benz Antos lorry, a grey Volkswagen Crafter van and a grey Citroen Picasso car.
Anyone who saw what happened, noticed any of the vehicles being driven shortly before the collision or who may have dash-cam footage is asked to contact Sussex Police online https://www.police.uk/contact/af/contact-us/or call 101, quoting Operation Drybrook .