In Osborne v. O'Brien, 114 Ill. 2d 35, 499 N.E.2d 455, 101 Ill. Dec. 867 (1986), the plaintiff sued the defendant for injuries he sustained while he was a passenger in a van that the defendant struck with his car. The undisputed facts revealed that the defendant was driving to work on a curvy, hilly, two-lane road, which descended 600 feet. Osborne, 114 Ill. 2d at 37, 499 N.E.2d at 456. As the defendant drove down the hill, his car slid on some ice, and despite his attempts to take corrective action, he crossed the centerline of the road and hit the van that had been stopped in the opposing lane. Osborne, 114 Ill. 2d at 37-38, 499 N.E.2d at 456. The record also showed that although the weather was damp, the defendant had no reason to suspect that the road would be icy. Osborne, 114 Ill. 2d at 37, 499 N.E.2d at 456. Following a trial in which the jury returned a verdict in the defendant's favor, the plaintiff filed a posttrial motion requesting entry of a judgment notwithstanding the verdict or in the alternative, a new trial. Osborne, 114 Ill. 2d at 39, 499 N.E.2d at 457. The trial court later denied the plaintiff's posttrial motion. Osborne, 114 Ill. 2d at 39, 499 N.E.2d at 457. The supreme court affirmed and, as part of its analysis, determined that the defendant had introduced evidence sufficient to submit to a jury on the question of whether the skid of his car was the result of some cause other than his negligence. Osborne, 114 Ill. 2d at 42, 499 N.E.2d at 458. In rejecting the plaintiff's argument that the evidence overwhelmingly favored granting her posttrial motion, the supreme court distinguished the two cases that the plaintiff relied upon (Sughero v. Jewel Tea Co., 37 Ill. 2d 240, 226 N.E.2d 28 (1967), and Calvetti v. Seipp, 37 Ill. 2d 596, 227 N.E.2d 758 (1967)), as follows: "Simply stated, the rationale of Sughero and Calvetti is that upon a plaintiff's showing that a collision between vehicles occupied by a plaintiff and driven by a defendant occurred on the plaintiff's side of the road, the plaintiff has made a prima facie case of the defendant's negligence. It is then incumbent on the defendant to adduce evidence to show that his vehicle was in that position because of some reason other than his own negligence. If he makes a showing sufficient to raise an issue of fact, the question of his negligence is for the jury." Osborne, 114 Ill. 2d at 41, 499 N.E.2d at 458.