The failure of the bus driver to blow his horn in apt time before attempting to pass the boy on his bicycle — a boy who had not looked back from the time the bus driver had first sighted him 150 yards ahead — was a violation of G.S. 20-149 (b), and evidence of negligence. Tallent v. Talbert, 249 N.C. 149, 105 S.E. 2d 426. Defendants concede that the trial judge allowed their motion for nonsuit upon the theory that Robert was guilty of contributory negligence per se in that, without giving any signal of his intention to do so, he veered suddenly from a direct line of travel when such a movement could not be made in safety. G.S. 20-154.
Nonsuit on the ground of contributory negligence may be allowed only when a plaintiff’s evidence, taken in the light most favorable to him, so clearly establishes the defendant’s affirmative defense that no other reasonable inference or conclusion can be drawn from it. 4 Strong, N. C. Index, Negligence § 26 (1961). Do the circumstances disclosed by plaintiff’s evidence establish thus conclusively that Robert was guilty of a violation of G.S. 20-154, and that such violation was a proximate cause of the collision which resulted in his death? The answer is No.
Except as to those provisions which by their nature can have no application, the operation of a bicycle upon a public highway is governed by the rules of the road applicable to motor vehicles. G.S. 20-38 (FF); Harris v. Davis, 244 N.C. 579, 94 S.E. 2d 649; Tarrant v. Bottling Co., 221 N.C. 390, 20 S.E. 2d 565. Therefore, under ordinary circumstances, it is the duty of a bicyclist, before turning from a direct line of travel, to ascertain that the movement can be made in safety, and to signal his intention to make the movement if the operation of any other vehicle will be thereby affected. The evidence here is susceptible to the following inferences: (1) Robert was oblivious to the bus behind him; (2) the bus driver should have realized this; (3) Robert had not intended to turn from his line of travel; and (4) his movement to the left was an involuntary one, caused by the unexpected and startling noise of an accelerating motor 10-20 feet behind him. In the aggregate, these are emergency, not ordinary, circumstances.
In Southwestern Freight Lines v. Floyd, 58 Ariz. 249, 119 P. 2d 120, plaintiff F, a 12-year-old girl, was riding as a guest on a bi*711cycle being operated at dusk by plaintiff S, a 16-year-old girl, in the outside lane for northbound traffic on a four-lane highway. They came upon the parked truck of defendant N and passed it. After they had proceeded 75-100 feet, the truck started up and followed directly behind them with its lights burning. When the truck was 15 feet behind them, S said, “That truck is going to hit us.” She turned to the left, toward the inside lane, and ran into the truck of defendant SW, which was in the act of passing N. Defendant SW’b truck had given no audible notice of its approach. Both plaintiffs recovered judgment against both defendants. In sustaining the recovery, the Arizona court said:
“That the operator of the bicycle, when she saw or heard the Northcutt truck 15 or 20 feet behind her, should be reasonably expected to continue on her course, unexcited, and take the chance she would not be run down, is hardly in accordance with human experience. One would rather expect her to become panicky and instantly seek some way of escape. That she failed to adopt a safe or the safest course, or to give statutory signals under section 66-111, does not relieve the defendant. It has long been settled that a party having given another reasonable cause for alarm cannot complain that the person so alarmed has not exercised cool presence of mind, and thereby find protection from responsibility for damages.” Id. at 257, 119 P. 2d at 124.
Greenberg v. Conrad, 220 Ill. App. 508, was a case in which the plaintiff’s intestate Thomsen, an adult riding a bicycle on a street in Waukegan, was struck from behind and killed by the defendant’s automobile. Evidence for the plaintiff tended to show that the defendant first sounded his “gong” when the automobile was just upon Thomsen and his bicycle, at which time the defendant “speeded up.” Thomsen turned to the left and was run down. In sustaining a judgment for the plaintiff, the court said:
“It is clear from all the evidence that Thomsen first learned of the approach of this automobile behind him when the gong first sounded when the automobile was right upon him. . . . ‘It has long been settled, that a party having given another reasonable cause for alarm cannot complain that the person so alarmed has not exercised cool presence of mind, and thereby find protection from responsibility from damages resulting from the alarm.’ . . . We are of opinion that the evidence warranted the jury in finding that the rule is applicable to the facts in this case, and that it was a question of fact for the jury whether Thomsen was acting with due care under the circumstances of *712the sudden danger which confronted him, and that the jury were warranted in finding that he was not guilty of contributory negligence.” Id. at 512-13.
As defendant Felton approached Robert on his bicycle, “a special hazard” existed. Felton might reasonably have apprehended that the bicyclist was oblivious of his approach and that he might be startled into involuntary action by a sudden and frightening noise behind him. It was, therefore, both Felton’s common-law and statutory duty to use due care not to endanger him. G.S. 20-140; G.S. 20-141 (c); G.S. 20-174(e); G.S. 20-149; Williams v. Henderson, 230 N.C. 707, 55 S.E. 2d 462; Tarrant v. Bottling Co., supra. One of those duties was to signal his approach in time to afford Robert a reasonable opportunity to avoid the danger from the passing bus. “This warning signal must be given to the driver of the vehicle in front in reasonable time to avoid injury which would probably result from a left turn or a crossing over the center of the highway to the left by the vehicle in front.” Boykin v. Bissette, 260 N.C. 295, 298, 132 S.E. 2d 616, 619. In the absence of such warning, knowledge that he is about to be passed may not be ascribed to the operator of the forward vehicle. Lyerly v. Griffin, 237 N.C. 686, 75 S.E. 2d 730. The fact that the engine of the overtaking vehicle is noisy, or even that it is carrying a rattling load, will not relieve a driver of his duty to give in apt time the warning required by statute. Devcchio v. Ricketts, 66 Cal. App. 334, 226 Pac. 11; 60 C.J.S., Motor Vehicles § 326(c) (1949).
We hold that plaintiff offered plenary evidence of defendants’ actionable negligence and that it was for the jury to say whether Robert was guilty of negligence which was a proximate cause of his tragic death.
The judgment of nonsuit is
MooRE, J., not sitting.