A workman is believed to have been about to repair a broken barrier on the side of a busy trunk road when he was fatally struck by a car.
Both Sussex Police and the Heath and Safety Executive are now investigating the death of Tony Saunders, 49, of Faircox, Henfield.
Mr Saunders died at 2.30pm on Monday on the A24 in Ashington, near Horsham.
Dean Collier, 39, who drove past the crash scene seconds after it happened, said Mr Saunders was lying on the ground next to his repair truck.
Mr Collier, speaking last night, said Mr Saunders’ colleagues told how he had been driving the lorry when they pulled over to repair a barrier.
One colleague got out to get cones from the back of the vehicle while Mr Saunders left the vehicle using another door.
As he walked around the front of the lorry he was struck by a Peugeot 307.
Mr Collier, who is from Essex but was on the way to Bognor to visit his girlfriend’s family, said: “He was lying in the road. I got out the car and I had a first aid kit, so I got that out and I called the emergency services.
“His colleagues were so shocked.”
Mr Saunders worked for Forest Traffic Service which declined to comment yesterday.
Friends paid tribute to Mr Saunders, including Lucy van Steenbergen who said: “I have known Tony from my early years and am so sad to hear of his demise.
“My thoughts go to Karen and his family at the loss of a wonderful person.”
Anyone with information should contact Sussex Police on 101.
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