¶1In running into the vehicle ahead of her, defendant failed to stop within the assured clear distance ahead, in violation of the specific requirements of Section 4511.21, Revised Code. Unless her conduct was legally excused, such violation constituted negligence per se.
¶2Under the authority of Spalding v. Waxler, 2 Ohio St. 2d 1, the operator of a motor vehicle has control over its brake equipment and the maintenance thereof, and he has a statutory duty to maintain the brakes in good working order at all times. Ordinary care is not sufficient to constitute compliance. Therefore, the brake failure in the instant cases was a self-created emergency. Such an emergency cannot serve as a legal excuse for failure to comply with the assured-clear-distance-ahead provision of Section 4511.21, Revised Code.
¶3Under the circumstances, there was no issue of sudden emergency or unavoidable accident in the cases. It was, there*11fore, error to give an instruction on the subject. See Ricks v. Jackson, 169 Ohio St. 254, 257.
¶4In the instant cases, defendant was negligent as a matter of law. Although the question of proximate cause is ordinarily one for the jury (see White v. Ohio Power Co., 171 Ohio St. 148; Clinger v. Duncan, 166 Ohio St. 216), reasonable minds could only conclude that in the instant cases defendant’s negligence was the proximate cause of the collision. The trial court should, therefore, have directed verdicts in favor of plaintiffs on the question of liability and submitted only the question of damages to the jury. See Kehrer v. McKittrick, 176 Ohio St. 192. The judgments of the Court of Appeals are, therefore, reversed.
¶5Judgments reversed.