Police in Gloucestershire said they were keen to speak to an HGV driver who was reported to them as repeatedly spitting at another motorist in a road rage incident.
They are appealing for witnesses to come forward following the episode in Gloucester last month.
The police said they had received a report that a white Volvo lorry driven by a man had pulled out in front of a Mercedes Benz van without any indication at the A417 roundabout towards Corinium Avenue, shortly before 5.45pm on Monday 21 July.
At the next set of lights, the driver of the van challenged the lorry driver, at which point the HGV driver became verbally abusive before repeatedly spitting at the Mercedes Benz driver.
Gloucestershire police said traffic was busy at the time of the incident and officers were now asking for anyone who may have witnessed the incident or had relevant dashcam footage to come forward.
Anybody with information is asked to contact Gloucestershire Police through the website, quoting incident 397 of 21 July.
