According to Tayside Police, the incident happened on the southbound A9 between Inveralmond and Broxden, Perth, about 12:30pm on Tuesday 13, April.
A spokesperson for Police Scotland said: “The female driver of a black Kia Sportage car had to slow down and pull into a layby when her car developed a fault.
“The driver of a red lorry which had apparently been behind the car and required to slow down due to this then pulled into the same layby, approached the car driver, and allegedly verbally abused her and assaulted her before driving away. She was not injured but was left very shaken.”
The lorry driver is described as a white male in his late 50s, about 5 feet 10 inches, and medium build with red hair and a freckled and tanned complexion. He was wearing a black polo shirt and black combat trousers.
Police Scotland added: “This incident happened at the side of one of Tayside’s busiest roads, and we like to hear from anyone who may have driven past and seen any part of this incident, especially if they have dashcam footage.”
Members of the public who have any information to assist the police with their enquiries are asked to call 101 – or speak to any officer.
Alternatively, information can be given anonymously by calling CrimeStoppers on 0800 555 111. The police reference for the incident is 1204 of 13th April.