The confrontation resulted in a man needing hospital treatment.
It took place at about 5.45pm on Friday (8 September), near the Cambridge Science Park, in Milton Road, and involved two men, a car driver and a motorcyclist.
The car driver, a man aged in his 40s, attended Addenbrooke’s Hospital with minor injuries.
The motorcyclist, a man aged in his 20s, did not require medical attention.
Detective Sergeant John Keerie said: “We are trying to find out exactly what happened in this incident, which left a man with injuries needing hospital treatment.
“It was rush hour at the time and I would like to hear from anyone who was in Milton Road and may have seen the incident or has dashcam footage.”
Anyone with information should report it through the force website using reference 35/67556/23.