A lorry driver who was hit by another lorry on the hard shoulder of the M5 remains in a critical condition.
Police are seeking witnesses to the crash between J7 and 8, near Worcester, at about 19:30 GMT on Monday.
Reports say he was standing at the back of his vehicle when he was struck by a passing lorry, West Mercia Police said.
The lorry failed to stop but was later found and the driver arrested on suspicion of causing serious injury by dangerous driving.
The 41-year-old man remains in police custody.
Sgt Steve Hastie, of the roads policing team, said the motorway had been busy at the time of the crash on the southbound carriageway and appealed for witnesses and dashcam footage.
“The victim remains in a critical condition in hospital and we need as much information as possible to help us progress with the investigation,” he said.