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 in Clockworks ) and Deathbird Stories. Available on-line as of 11 December 2006: here.
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)