A 33-year-old motorist has been arrested for threatening another driver with a metal pole during a road rage incident at a set of traffic lights in Kewdale.

The road rage incident occurred yesterday morning in full view of police at an intersection on Tonkin Highway just before Leach Highway.

Police say that at about 9.40am traffic enforcement officers were on patrol in a marked police vehicle travelling south on Tonkin Highway when they allegedly saw a man get out from the drivers side door of a Toyota Hiace which had stopped at a set of traffic lights.

It is alleged the man was carrying a 50cm long piece of metal pipe when he approached the van stopped in front of his vehicle and began banging on the driver's side window of the vehicle with his hand.

It is alleged he began waiving the pipe around in a threatening manner.

Police apprehended the 33-year-old man and took him to the Belmont Police Station where he was charged with being armed in a way that may cause fear.

He will appear in the Perth Magistrates Court on Wednesday.

PERTH LEE RONDGANGER