Meta: isfdb. This SF short story first appeared 1969 in his collection „The Beast That Shouted Love at the Heart of the World“.
Synopsis: In a near future, freeway drivers on the 101 Pacific Coast Highway challenge one another to mortal duels under official supervision. Family man George upgraded his family car and can’t resist a provocation from a punk cutting him on a cruise with his wife. The road rage and ritual duel turns to a deadly battle using futuristic enhancements.
Review: A fun read: Simple style, driving plot, natural injection of information about the enhancements, and interesting interaction between unlikeable George, his wife and the other driver. Who isn’t annoyed when cut, hm?