The mere happening of an accident does not of itself raise any presumption of negligence on the part of the defendant. ( Brown v. Boyles, 27 Ill. App.2d 114; Rotche v. Buick Motor Co. 358 Ill. 507.) However, the evidence without contradiction discloses that at the time of the collision the plaintiff was traveling easterly at a rate of 20 miles per hour on Route 20, a through highway.

When all the evidence is examined in its aspect most favorable to defendant, we find, at most, a disputed factual question as to whether defendant was negligent. Certainly the mere fact that defendant's vehicle slid on ice is not in itself evidence of negligence. (See, e.g., Brown v. Boyles (1960), 27 Ill. App.2d 114, 169 N.E.2d 273.) In this regard the statement of the court in Ferdinand v. Lindgren (1961), 32 Ill.2d 133, 140, 177 N.E.2d 10, 14, is instructive:

• 5 The burden is on the plaintiff to prove negligence ( Russell v. Rowe (1967), 82 Ill. App.2d 445, 448, 226 N.E.2d 652), not on the defendant to disprove it. ( Brown v. Boyles (1960), 27 Ill. App.2d 114, 124-25, 169 N.E.2d 273.) The occurrence of an accident, even where the plaintiff has exercised ordinary care, does not of itself raise any presumption of negligence on the defendant's part.

Rosenkrans v. Barker (1885), 115 Ill. 331, 3 N.E.2d 93; Magill v. George (1952), 347 Ill. App. 6, 105 N.E.2d 808. • 4, 5 However, Melroy concedes that there was testimony regarding the observed speed of her automobile as 10 to 15 miles per hour and its stopping distance after the impact, a car length or less. This testimony, plus the ample evidence regarding the circumstances of her driving — that she was entering a service station and executing a turn — gave the jury a factual basis sufficient to judge whether her speed was reasonable and proper, because the question of what speed is reasonable and proper depends on the surrounding circumstances ( Brown v. Boyles (1960), 27 Ill. App.2d 114, 169 N.E.2d 273). That this was an issue of fact for the jury to decide is not negated by the fact that the evidence includes testimony that Melroy's speed was not unusual for automobiles traveling through the station because the fact that an automobile's speed is in accordance with the norm does not necessarily mean it is safe. Figarelli v. Ihde (1976), 39 Ill. App.3d 1023, 351 N.E.2d 624; Guffey v. Gale (1947), 332 Ill. App. 207, 74 N.E.2d 730. • 6 Because there was evidence both as to the speed of Melroy's vehicle and the surrounding circumstances, the reasonableness of her speed was an issue for which a factual basis was laid and it was appropriate to instruct the jury on this issue.

The burden is on plaintiff to prove negligence ( Russell v. Rowe (1967), 82 Ill. App.2d 445, 226 N.E.2d 652), not on defendants to disprove it. ( Brown v. Boyles (1960), 27 Ill. App.2d 114, 169 N.E.2d 273.) Even where plaintiff has been rear-ended, it is for the jury to decide if it was negligence or unavoidable accident.

When all the evidence is examined in its aspects most favorable to defendant, we find, at most, a disputed factual question as to whether defendant was negligent. Certainly the mere fact that defendant's vehicle slid on ice is not in itself evidence of negligence. (See, e.g., Brown v. Boyles (1960), 27 Ill. App.2d 114, 169 N.E.2d 273.) In this regard the statement of the court in Ferdinand v. Lindgren (1961), 32 Ill. App.2d 133, 140, 177 N.E.2d 10, 14, is instructive:

The trial court directed a verdict in favor of defendants at the close of plaintiff's evidence; it therefore gave no instruction similar to the one in the instant case. The Appellate Court first recognized that "the mere happening of an accident, together with the exercise of ordinary care by plaintiff, does not raise any presumption of negligence on the part of the defendants," citing (among countless other cases which would have been available declaring this principle), the case of Brown v. Boyles, 27 Ill. App.2d 114, 169 N.E.2d 273, which involved a collision between two vehicles and affirmed a judgment which found all parties not guilty. This proposition I can understand. (For examples of later vehicle collision cases standing for the same principle, see Russell v. Rowe, 82 Ill. App.2d 445, 226 N.E.2d 652; Nilsson v. Checker Taxi Co., 4 Ill. App.3d 718, 281 N.E.2d 721, and Malone v. Chicago Transit Authority, 76 Ill. App.2d 451, 222 N.E.2d 93, both of the last two cases involving defendants which as common carriers owed their plaintiffs the highest degree of care.) The Krump court, nevertheless, then went on to hold that the collision of the two automobiles did constitute a prima facie case of negligence on the part of one or both of the drivers, prompting reversal and remand for a new trial which would require defendants to go forward with their proof which might establish negligence on the part of one or both defendants. This proposition I cannot understand.

The mere happening of an accident does not of itself raise any presumption of negligence on the part of a defendant." Brown v. Boyles, 27 Ill. App.2d 114, 124, 169 N.E.2d 273. [5, 6] Requiring no citation of authority is the proposition that negligence consists in a failure to exercise the standard of care of a reasonably prudent person under the circumstances of the case.

The mere happening of an accident, together with the exercise of ordinary care by the plaintiff, does not of itself raise any presumption of negligence on the part of the defendant. Krump v. Highlander Ice Cream Co., 30 Ill. App.2d 103, 105, 173 N.E.2d 822; Brown v. Boyles, 27 Ill. App.2d 114, 124, 169 N.E.2d 273. The record before us does not contain the trial court's instuctions to the jury. We must assume that the jury was properly instructed.

[1, 2] We may not disturb the verdict of the jury as being contrary to the manifest weight of the evidence unless it is clearly evident from a consideration of all of the evidence that an opposite conclusion should have been reached. Payne v. Kingsley, 59 Ill. App.2d 245, 249, 207 N.E.2d 177 (1965); Brown v. Boyles, 27 Ill. App.2d 114, 124, 169 N.E.2d 273 (1960). Stated differently, we may substitute our judgment for that of the jury only where the latter's verdict is palpably erroneous and wholly unwarranted from the manifest weight of the evidence.