A 47-year-old man is in a serious condition in hospital after being stabbed in the neck in Bedford.
The man, who was driving an Astra car, had pulled up outside a house in Rooksmead, when he became involved in a row with another man driving a Mondeo.
Following the incident, the driver of the Mondeo left the scene, but was arrested nearby at the home of a relative.
Bedfordshire Police say a 44-year-man is in custody at Greyfriars Police Station in the town.
They are appealing for witnesses to the row, which happened at 1920 BST on Sunday as both men pulled up at the house.