Australian director George Miller's new film, "The Road Warrior," fits loosely into the science-fiction genre, set as it is in a world devastated by wars and reduced to bands of vicious, marauding nomads searching the burned-out highways for gasoline. "The Road Warrior" isn't the film's title outside this country; elsewhere it's "Mad Max 2," a sequel to the action film that did remarkable business everywhere except the United States -- where it died quickly, leading the producers to conclude that calling this one a sequel would cause another fast box-office death. Not only has the retitled film gotten off to a good start in the theaters, but it's also picked up the nearly unanimous rave reviews that everybody figured would be the sole province of "E.T." this summer. So now we've got two movies that just about every critic in the country loves and the two are leagues removed. "The Road Warrior" lacks any lines as endearing as the question one of "E.T.'s" grade-school heroes asks as he leaves his alien friend behind to attend class -- "How do you explain school to higher intelligence?" -- but there's good reason for that: Of the 110-page script for "The Road Warrior," only 10 pages contain dialogue.