“Stupid games” by two drivers on the M32 caused a four-car shunt.
Morris Goode was driving a VW Caddy when he tussled for position with a Volvo car, Bristol Crown Court heard.
After they undertook each other and braked they collided, prompting two vehicles to collide behind them.
Goode, 59, of Clifton Road in Weston-super-Mare, pleaded guilty to careless driving on August 15, 2019.
The Recorder of Bristol His Honour Judge Peter Blair QC fined him £300, with £85 costs and a £32 victim surcharge.
He told Goode: “You were playing stupid games with another vehicle coming down the M32.
“There was a collision. It not only affected you and the other driver but others as well. It caused quite a lot of damage and upset.”
The judge put eight penalty points on Goode’s driving licence.
Alec Small, prosecuting via video link, said the Volvo undertook Goode and briefly braked, before Goode undertook the Volvo as they headed towards the city.
When the Volvo made contact with Goode a following Mercedes backed off, and was hit by a camper van.
Goode left his details at the scene of the shunts, the court heard.
He told police a dog had ran out from the central reservation, but there was no evidence to back up the claim.
The driver of the Volvo also admitted careless driving and was dealt with by Bath magistrates.
David Scutt, defending, said his client left his details at the scene but was subjected to racist abuse and left to avoid a confrontation.
Mr Scutt said Goode suffered from anxiety and depression but driving helped his mental health and he aspired to work as a courier.