Along the Scenic Route
Ellison, Harlan. "Along the Scenic Route" (vt "Dogfight on 101"). Amazing, Sept.1969. Coll. HE's The Beast that Shouted Love at the Heart of the World (cited under Anthologies) and Deathbird Stories.
Near-future world where automobile duels are sanctioned by the State, with the cars armed; cf. and contrast R. Morgan's novel, Market Forces. (RDE, 11/12/06)