A pedestrian is in a critical condition in hospital after the driver he was urging to slow down punched and knocked him out.
The 40-year-old was knocked to the floor with a single punch and suffered a serious head injury.
It happened at around 3pm on Sunday along Newland Grove, Dudley, when the driver pulled over and approached the man.
A 25-year-old male was arrested at an address in Netherton and is being questioned by officers.
Police are appealing for witnesses.