David Seddon, 49, faces 25 years in prison.
Seddon was found guilty in last January's murder of Allen Lauritzen, 40.
Two days after the incident, Lauritzen died of wounds to his chest.
Prosecutors said the men were arguing over the CB radio and then Seddon began tailgating Lauritzen's truck.
Seddon pulled over and started fighting with Lauritzen before stabbing him.