He was convicted of first-degree murder in November after admitting he knifed 40-year-old Alan Lauritzen of Sparta, Wis., after they both pulled off on the Edens Expressway near suburban Northbrook. Seddon said he was acting in self-defense.
Prosecutors said it was an argument on the CB radio that led to the road rage incident.
Lauritzen's family asked for the maximum 60 year sentence. He suffered a punctured lung and severed aorta.