A man has been arrested on suspicion of murdering a 79-year-old driver in a suspected road-rage confrontation.
It was reported earlier that a 79-year-old motorist was stabbed to death by another driver he was involved in a road accident with.
Don Lock was repeatedly stabbed near Findon, West Sussex, at about 20:40 BST on Thursday.
Sussex Police said a 34-year-old man from Worthing was arrested by armed officers on Friday afternoon.
Mr Lock, who was recently given the all-clear from cancer, was knifed after getting out of his car after a crash with another vehicle on the A24.
He was treated by paramedics but died at the scene.