Officers were called to Old Crown Road on Saturday, March 25, at around 6pm.
The victim, a man in his 40s, had been driving in the area when a second car approached his vehicle.
The driver of the second vehicle got out of the car and assaulted the victim.
He received a serious head injury in the incident and was taken to hospital for treatment.
Det Insp Tim Hunt, of Wakefield District Police, said: “This was an extremely distressing incident which has left the victim with a significant injury.
“We are continuing our enquiries to trace those responsible for this attack and would appeal for anyone with information to please get in touch.
“Likewise, we would ask anyone who witnessed the incident and hasn’t yet spoken to police, to please get in contact.”
Anyone with information is asked to contact Wakefield District Police on 101, quoting crime reference 13170136148.
Information can also be passed anonymously to independent charity Crimestoppers on 0800 555 111.