With almost insolent ease, Duel … displays the philosopher's stone which the Existentialists sought so persistently and often so portentously: the perfect acte gratuit, complete, unaccountable and self-sufficient. Steven Spielberg … sets the scene brilliantly from the outset….

The glory of Richard Matheson's script is that there are no motivations, no explanations, simply the archetypal rivalry of the road carried to reductio ad absurdum heights. At first there are moments of unease—the commercial traveller's name, after all, is Mann—in the telephone call to his wife which suggests a background of marital stress, in the rather coy insistence … with which his efforts to put a face to his rival are frustrated. But all these hints of allegory (man's inability to cope with machine-age pressures) are held firmly in check, giving just a touch of abstract meaning to the unseen lorrydriver, just a touch of social fallibility to the ineffectual...