The incident took place on the A7 around 6 p.m. on Wednesday 9th November on the southbound carriageway between Stow and Galashiels, close to its B710 junction for Clovenfords.
A 66-year-old man was travelling in his silver Hyundai iload pick-up vehicle when the male driver of a white and green van signalled for him to pull over.
The pair became then involved in a verbal dispute and the suspect punched the man to the face before smashing his pick-up’s wing mirror and driving off.
The victim sustained minor facial injuries but did not require medical attention.
Anyone who can assist officer with their inquiries into this incident is asked to come forward.
Constable Sarah Younger from Galashiels Police Station said: “This dispute and subsequent assault seems to have been over a relatively minor issue, but resulted in the victim being assaulted and his vehicle being damaged.
“I would ask that anyone who was on the A7 on Wednesday evening and witnessed this exchange, or who has information that can help us identify the suspect, contacts police immediately.”
Anyone with information is asked to contact Police Scotland on 101 or make an anonymous report through Crimestoppers on 0800 555 111.