A dispute at traffic lights on an M5 motorway sliproad led to a car passenger being stabbed.
The knifing at the Weston-super-Mare junction happened after a row erupted between the occupants of two vehicles, on Friday
A man was later arrested over the knifing after emergency crews were called at about 22:15 BST.
A 26-year-old man was taken to hospital with non-life-threatening injuries, Avon and Somerset Police said.
The 42-year-old suspect, from Birmingham, has been arrested on suspicion of wounding with intent and remains in custody.
“The victim was a passenger in a car which had just exited the M5 at this junction and was at a set of traffic lights,” Avon and Somerset Police said in a statement.
“A dispute then ensued with the driver of another car, following which the victim was stabbed.”