Defendants offered evidence. Hence, the only motion for judgment of nonsuit to be considered is that made at the close of all the evidence. G.S. 1-183; Atkins v. Transportation Co., 224 N.C. 688, 32 S.E. 2d 209.
In determining its sufficiency for submission to the jury, the evidence, whether offered by plaintiff or by defendants, must be considered in the light most favorable to plaintiff. Singletary v. Nixon, 239 N.C. 634, 80 S.E. 2d 676; Williamson v. Clay, 243 N.C. 337, 90 S.E. 2d 727. Under the rule stated, there was no error in submitting the case to the jury.
There was plenary evidence that Murray (with his back towards Boyle), and the Jones truck, were standing at the north end of the “refuse pile” directly in the path of the Boyle truck while it backed downgrade and pinned Murray between the two trucks. Moreover, the evidence, including Boyle’s testimony, tended to show that, while backing, he could not see what was behind him; and that Boyle gave no signal by horn or otherwise before he started to back or while backing.
In view of the evidence that both Murray and the Boyle truck were in fact directly behind him, it was for the jury, upon all the evidence, to say whether Boyle failed to use due care in backing his truck without first exercising due care to ascertain whether he could do so without striking Murray or the Jones truck. Adams v. Service Co., 237 N.C. 136, 74 S.E. 2d 332. There is little difference between backing a truck when you cannot see what is behind you and in driving forward when blindfolded.
Conceding, as contended by defendants, that the Boyle truck moved at “a normal speed for backing up,” there was evidence of a special hazard. See: G.S. 20-141 (a) (c); Baker v. Perrott, 228 N.C. 558, 46 S.E. 2d 461. Any speed may be unlawful and excessive if the operator of a motor vehicle knows or by the exercise of due care should reasonably anticipate that a person or vehicle is standing in his line of travel.
As indicated above, defendants, by way of new matter constituting a defense (G.S. 1-135(2)) and by way of contributory negligence (G.S. 1-139), alleged that Boyle backed his truck as directed by Murray. The burden of proving such affirmative defense was on defendants. MacClure v. Casualty Co., 229 N.C. 305, 49 S.E. 2d 742. The same rule applied to defendants’ plea of contributory negligence. Hunt v. Wooten, 238 N.C. 42, 76 S.E. 2d 326, and cases cited. It is noted that these allegations were expressly denied in plaintiff’s reply thereto.
Defendants’ said allegations, and defendants’ evidence in support thereof, constituted the backbone of their defense. The jury was at *129liberty to reject them and did so. Certainly, the undisputed.evidence here, taken in the light most favorable to plaintiff, did not establish plaintiff's contributory negligence so clearly that no other reasonable inference or conclusion could be drawn therefrom. Dennis v. Albemarle, 243 N.C. 221, 90 S.E. 2d 532.
Nor did the court err in refusing to give defendants’ requested peremptory instruction, to the effect that they would answer the contributory negligence issue, “Yes,” if they found the facts to be as all the evidence tended to show. The court did instruct the jury that if they found from the evidence and by its greater weight, first, that Murray was negligent “in that he failed to see what he should have seen, that he failed to keep a proper lookout and failed to exercise proper care for his own safety or that he signaled the driver to back in there and then stepped into the way of it or that he failed to keep looking and seeing what he would have seen,” and second, that such negligence on the part of Murray was a proximate cause of Murray’s death, they would answer the contributory negligence issue, “Yes.” The instructions given were in substantial compliance with the requirements of G.S. 1-180.
Concerning the testimony of Perkins and of Perry, defendants insist that, from where they were, they could not have seen what they testified they did see. It is elementary that the probative value of their testimony was for the jury.
Even so, defendants contend it was error to permit Perkins and Perry to testify that they did not see Murray give any signal to Boyle and did not see Boyle give any signal, by hand, horn or otherwise, before or while he backed his truck. As to the latter, Boyle made no contention that he gave any signal. As to not seeing a signal by Murray, the gist of the testimony of Perkins and of Perry was that Murray was dealing with Jones, at his truck, facing away from Boyle, when Boyle started and continued to back his truck. And Jones testified, without objection, as follows: “I did not at any time see him turn his face in the direction of the truck of Joe Boyle, or give any signal in that direction whatsoever. I did not hear the sound of any horn or signal from the truck of Joe Boyle as it backed towards the rear and into the rear of my truck.”
Defendants insist further that the court, even in the absence of special request, should have instructed the jury specifically “concerning the probative value, weight or effect of 'negative’ testimony.” Neither defendants’ assignment of error nor their brief advises us as to the instructions they considered appropriate. In some cases, where defendant’s motion for judgment of nonsuit turns on the sufficiency of certain negative evidence to take the case to the jury, the court must say as a matter of law whether such negative evidence has any probative value. Johnson & Sons, Inc., v. R. R., 214 N.C. 484, 199 S.E. 704. But when *130the evidence, apart from such negative evidence, is sufficient to take the case to the jury, the rule is that the trial court may not comment on the weight of evidence, negative or otherwise. Carruthers v. R. R., 218 N.C. 49, 9 S.E. 2d 498. The decision in the Carruthers case was reversed on rehearing, 218 N.C. 377, 11 S.E. 2d 157; but this was on the ground of invited error, that is, the erroneous instructions were prepared by appellant and given by the court at his specific request. On rehearing, the Court adhered to the law as stated in the original opinion.
The defendants insist that the court erred in instructing the jury as follows:
“Gentlemen, I instruct you that if you find that there was an estab- , lished practice pertaining to the manner of moving motor vehicles at ‘that mixing plant site and-that such practice was reasonable and that such practice was for the reasonable safety of those engaged in working thereon and that such practice required the operators of motor vehicles thereon to await a signal from the foreman before moving thereon, and that such practice was known to the said Joe Boyle, or in the exercise of reasonable care, should have been known by him, then the Court instructs you it would have been the duty of Joe Boyle to abide by signals from the foreman and failure so to do would be negligence.”
As indicated above, Perkins testified to the existence of such a practice. But, apart from his testimony, there is ample evidence thereof. Indeed, Boyle testified that he pulled up and waited for instructions from Murray. On cross-examination, he testified that Murray “would show us where to unload and directed me.” As indicated above, Hutchins testified that he stopped, waiting for Boyle to get a signal from Murray; and that he too was waiting for a signal before starting his truck. As indicated above, Jones backed his truck to the north edge of the “refuse pile” for dumping as directed by Murray. There was evidence that defendants’ trucks had been loading and unloading at this plant site five or six weeks. Too, Boyle, then 18 years old, testified that he had operated defendants’ dump truck some four months, part of the time at this plant site, loading and unloading in accordance with Murray’s directions. The foregoing suffices to warrant the instruction. Indeed, Boyle’s testimony, including his alleged reliance on Murray’s directions, tends to show that the practice existed and that he was well aware of such practice.
The crux of this case was whether Boyle backed his truck in accordance with instructions from Murray. It is evident that the jury did not accept defendants’ evidence and contention. Perhaps they thought it unreasonable that Murray, standing at the Jones truck then backed to the “refuse pile” for unloading, would give directions to Boyle to back his truck to the very same spot. Too, while Boyle and Hutchins testi*131fied that Murray gave certain directions to Boyle, it is noteworthy that, as indicated above, the testimony of Jones was contra.
We have discussed the assignments of error on which defendants appear to lay maj or emphasis. The others are too numerous to warrant discussion in detail. Suffice to say, each has been carefully considered; and we find no error sufficiently prejudicial to warrant a new trial. Indeed, the impression prevails that the case was well and fairly tried in accordance with settled principles of law.
JOHNSON, J., not sitting.