Police say a "brick-sized" lump of concrete that hit a van driver's windscreen before he crashed on the M11 in Essex wasn't thrown from a bridge.
The man, who was in his 60s and from Sible Hedingham, lost control of his van and hit a tree following the incident near Birchanger just before 5pm on Wednesday evening.
The death is still being treated as suspicious at this stage, but officers say they're now confident that the concrete didn't come from a bridge or the roadside.
The Goose Lane bridge near Little Hallingbury, which crosses the motorway, was closed while forensic work was carried out.
Police are still keen to talk to anyone who was driving in the area at the time of the crash, and have appealed for any dash cam footage to be sent to them.