This is an action for wrongful death arising out of a collision between the plaintiff’s decedent’s automobile and defendant’s log loader. Defendant filed a counterclaim for damages to its log loader. Oregon’s comparative negligence statute, OES 18.470, was in effect at the time of the accident. The jury, by “SPECIAL FINDINGS OF FACT” (ORS 17.415), found that plaintiff’s decedent- was 56 percent negligent and defendant was 44 -percent negligent. The trial court entered judgment that plaintiff “recover nothing under the complaint” and that, def endant.“recover nothing on *427its counterclaim * * Plaintiff appeals and defendant cross-appeals.
The accident occurred at approximately 11:30 p.m. on September 10,1971, on Highway 74 near Heppner, Oregon. Defendant operated a lumber mill on property which was bisected from north to south by Highway 74. Felix Sehwarzin, defendant’s employee, had been operating the log loader in a yard in the southwest portion of the mill. As Sehwarzin was driving the machine north on Highway 74 to a storage garage located across the highway, the decedent’s vehicle ran into the rear end of the log loader in the east lane of traffic.
The log loader was a 25-ton, four-wheeled vehicle equipped with four flood-type headlights directed forward and two flood-type headlights and two red taillights directed to the rear.
Sehwarzin testified that at the time of the accident all of the log loader’s lights were illuminated and his speed was between ten and twelve miles per hour. The log loader was not equipped with a rearview mirror or a slow-moving vehicle emblem.
Prior to the accident, plaintiff’s decedent was observed having drinks in two cocktail lounges. The decedent left the Wagon Wheel Lounge in Heppner at approximately 11:30 p.m. and headed north on Highway 74. Several minutes later decedent’s vehicle struck the rear end of defendant’s log loader at a speed estimated to be between 65 and 85 miles per hour, leaving no skid marks. An analysis of the decedent’s blood established the alcohol content at .17 percent. The designated speed was 55 miles per hour.' •
*428In the original complaint, plaintiff alleged that defendant was negligent “[i]n operating said vehicle [log loader] on a public highway when there was available for defendant’s use a private road immediately adjacent to said public highway; * * This allegation referred primarily to a private dirt road maintained by defendant along the east side of Highway 74. On defendant’s pretrial motion, the presiding court struck this allegation from the complaint and the trial court refused to reinstate the allegation at trial or permit plaintiff to adequately introduce proof on the subject of the alternate route. These rulings form the basis of plaintiff’s first two assignments of error.
The decision to strike certain allegations from a pleading rests within the sound discretion of the trial court, and this court will not reverse that decision unless an abuse of discretion is shown. McGinnis et al v. Keen, 189 Or 445, 449, 221 P2d 907, 909 (1950). Plaintiff failed to plead facts sufficient to show that defendant owed plaintiff’s decedent any duty to use an alternate route. The bare statement that defendant was negligent in failing to use another road will not suffice. This court stated in Klerk v. Tektronix, Inc., 244 Or 10, 13, 415 P2d 510, 512 (1966):
“It is well established that actionable negligence arises only from the breach of a duty owed by one person to another, and that to state a cause of action for negligence the complaint must state the duty imposed or facts from which the law will imply a duty. * * *”
The trial court was clearly within its discretion in striking this allegation and refusing to reinstate it at trial. Since the subject of alternate routes was outside the scope of the pleadings, evidence concerning that *429subject was properly excluded. ORS 41.230. See Gabel v. Armstrong, 88 Or 84, 171 P 190 (1918), where this court held that evidence offered to prove allegations which had been excluded from the case was properly refused.
The plaintiff also argues that “ [f jurther evidence regarding alternate routes was kept from the jury and plaintiff was admonished not to argue the failure to use alternative routes even though evidence came in during trial, without objections, as to alternative routes” and that “the use of the highway by defendant’s vehicle when there were alternative routes available and known to defendant and there was no emergency requiring defendant to use the public highway then • defendant would be negligent when it took the highway route in preference to the alternate routes * *
“Consideration must also be given to any alternative course open to the actor. Whether it is reasonable to travel a dangerous road may depend upon the disadvantages of another route; and while mere inconvenience or cost may not in themselves be sufficient to justify proceeding in the face of great danger, they may justify taking other risks which are not too extreme * * *.
“The alternative dangers to the actor himself and to others must be thrown into the scale, and a balance struck in which all of these elements are weighed.” W. Prosser, Law of Torts 148-49, § 31 (4th ed 1971).
Plaintiff made an offer of proof but it consisted solely of a number of other automobiles being detoured around the scene of the accident on the alternate route. This would prove that automobiles could use the alternate route, but there is nothing in the proof to show that ■ such route was available to a vehicle with the weight *430of the log loader or that he proceeded on the highway “in the face of great danger.”
Plaintiff makes no contention in his pleadings that defendant’s log loader was unlawfully on the highway. Plaintiff seems to argue in light of the loader’s size and slow speed and the type <of equipment or lights on the vehicle that it should “be considered negligence to place this vehicle on the highway at 11:20 p.m. when no emergency existed and there was no good reason for the vehicle to be .on the highway at that time of night or at any other time.” If it had been daylight, rather than darkness, it is difficult to understand how the operation of the loader on Highway 74, rather than on some alternate route, could constitute negligence. Plaintiff’s decedent had a clear view on straight roadway for one quarter of a mile. With Oregon’s economy consisting primarily of lumber and agriculture, we accept logging trucks, heavy equipment, and tractor-trailers as part of highway traffic, and the reasonable, prudent man accepts and guards against it although he may not find it to his liking. It is part of the uniform standard of behavior by the hypothetical reasonable, prudent man. If one was to drive a pickup truck overloaded with firewood at a slow speed on the highway rather than on an available alternate route, would such an act support an allegation of negligence grounded on failure to use an alternate route? We think not. If no alternate route was available we would consider the overloading, control, and speed of the vehicle as elements of negligence to be submitted to the jury. In the present case the plaintiff alleged that the defendant was negligent:
“1. In operating said log loader at night with two white lights illuminated facing the rear * * *.
*431“2. In operating said vehicle during the hours of darkness without displaying red illuminated lights on the rear of said vehicle.
“3. In operating said vehicle on a public highway at an unreasonably slow speed without warning plaintiff’s decedent of said vehicle’s slow speed.
“4. In operating said vehicle on a public highway when in the exercise of reasonable care, defendant knew or should have known said vehicle was in an unsafe condition so as to endanger other persons using said highway, * * *.
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and in failing to maintain proper lookout and control. The court submitted these allegations of negligence with all the evidence to the jury for its consideration.
We find the court did not err as contended by plaintiff’s first two assignments of error.
During trial, plaintiff elicited testimony from Felix Schwarzin, the driver of the log loader, which indicated that the vehicle had no rearview mirror and that defendant had never instructed Schwarzin on how to turn off the loader’s rear headlights. After both parties had rested, plaintiff moved to amend its complaint to add these facts as specifications of negligence. The court denied the motions and the rulings are assigned as error by plaintiff.
A trial court is authorized by OES 16.390 to permit parties to amend their pleadings to conform to the facts proved at trial, but the decision to permit such amendments is within the court’s sound discretion. This court will not disturb the trial court’s decision unless it clearly appears that the discretion was abused to the prejudice of one of the parties. Sackett v. Mitchell, *432264 Or 396, 505 P2d 1136 (1973); Morrill v. Rountree, 242 Or 320, 408 P2d 932 (1966).
ORS 483.450 requires motorists to equip their vehicles with a rearview mirror. Defendant’s failure to comply with this statute raised a rebuttable presumption of negligence. See Freund v. DeBuse, 264 Or 447, 506 P2d 491 (1973). However, proof of negligence, by presumption or otherwise, should not be confused with proof of causation.
“* * * [T]he unexcused violation is negligence ‘per se,’ or in itself. The effect of such a rule is to stamp the defendant’s conduct as negligence, with all of the effects of common law negligence, but with no greater effect. There will still remain open such questions as the causal relation between the violation and the harm to the plaintiff * * W. Prosser, Law of Torts 200-01 (4th ed).
The requirement of proof of causation is further explained in the following frequently quoted passage from Mr. Justice Cardozo’s opinion in Martin v. Herzog, 228 NY 164, 170, 126 NE 814, 816 (1920):
“We must be on our guard, however, against confusing the question of negligence with that of the causal connection between the negligence and the injury. A defendant who travels without lights is not to pay damages for his fault unless the absence of lights is the cause of the disaster. A plaintiff who travels without them is not to forfeit the right to damages unless the absence of lights is at least a contributing cause of the disaster. To say that conduct is negligence is not to say that it is always contributory negligence. ‘Proof of negligence in the air, so to speak, will not do’ (Pollock Torts [10th ed.], p.472). * * *” (Emphasis added); quoted with approval in Landis v. Wick, 154 Or 199, 209-10, 57 P2d 759, 763, 59 P2d 403 (1936).
*433We are unable to find any evidence that the lack of a rearview mirror on the log loader contributed in any degree to the accident. Had there been no violation of this statute, the accident would have occurred just as it did. Cf. Henthorne v. Hopwood et al, 218 Or 336, 348, 338 P2d 373, 345 P2d 249, 252 (1959).
The court could have allowed plaintiff’s request to amend his pleadings to show defendant’s negligence in failing to instruct Schwarzin on how to operate the light switch, but it raises a different question. This request came after both parties had rested. The court had excused the jury for the day and told them, “We will recess until tomorrow morning at 9:30 when the only matters at that time will be the respective statements of counsel to you, the Court’s instructions as to the law applicable to this case, and then the matter will be submitted to you for your consideration.”
Prior to trial plaintiff’s counsel deposed Schwarzin, operator of the log loader. It is argued that Schwarzin’s deposition① left plaintiff with a misleading impression that Schwarzin knew how to operate the light control switch and that he did not know until plaintiff called Schwarzin as a witness that no one had told Schwarzin how to turn off the back white lights and still leave the red taillights burning (in trial of the case plaintiff attempted to prove that the bright rear headlights on the loader had caused the accident).
This court has spoken on numerous occasions as to when amendments to pleadings should be allowed or denied. Generally, we say that the court has ample discretionary authority to allow amendments, Watson *434v. Dodson, 238 Or 621, 395 P2d 866 (1964), provided the proffered amendment does not substantially change the cause of action or interject an entire new element of damage. Wood v. Southern Pacific Co., 216 Or 61, 72, 337 P2d 779 (1959); Maerz v. The J-C Company, Inc., 223 Or 536, 539, 355 P2d 94 (1960). Cf. Wells v. Washington County, 243 Or 246, 249, 412 P2d 798 (1966).
One factor the court should consider in determining whether to permit an amendment after both parties have rested their cases is whether the movant knew or reasonably should have known earlier in the case of the need to amend his pleadings.
“Where the party seeking the amendment has reasonable means of learning or has knowledge prior to trial of the circumstances which make it desirable for him to amend, a slight chance that the other party will be prejudiced will justify a refusal of the requested amendment. * * *” Quirk v. Ross, 257 Or 80, 83-84, 476 P2d 559, 561 (1970).
See also, Boyer v. Dawson, 216 Or 393, 395, 337 P2d 785, 786 (1959); Hopfer v. Staudt, 207 Or 487, 494-95, 298 P2d 186, 190 (1956).
Here the plaintiff could have deposed the operator, Schwarzin, more thoroughly and other defendant employees more knowledgeable in the operation of the lights of the log loader. Also, the log loader could have been visually inspected. The trial judge’s statement at the time he denied the motion to amend the pleadings best describes the court’s dilemma:
“* * * We have had the completion of the case. I now recognize that Mr. Hawkins says that in the taking of the deposition from the witness he indicated the operation of the switch. There has been no indication whether or not plaintiff in any way *435examined this equipment themselves or had anyone examine it for them or inspect it for them to check it out. And it does appear that to come in now, after all the evidence has been concluded, the Court has instructed the jury that all of the testimony has been presented which wall be presented, the jury has been excused, it does place a burden upon defendant to not be able to answer something that was not in issue at any time in the pleadings * *
Under the circumstances of this case, we do not believe that the court erred in denying this motion to amend.
Plaintiff assigns as error the refusal of the court to give the following requested jury instruction:
“I instruct you that the operator of any vehicle has a continuing duty to maintain a slow moving vehicle emblem on his vehicle in conformity with ORS 483.457 if said vehicle is designed to operate at speeds less than 25 mph and he must exercise the highest degree of care in the discharge of this duty.
“If you find from all of the evidence, if any, that the defendant did not exercise the highest degree of care in installing and maintaining such an emblem, then you are justified in finding defendant was negligent in the operation of said vehicle.
10. The language of this instruction was taken from Hyster Co. v. Willis-Shaw Frozen Exp., 261 Or 534, 594 P2d 710 (1972), where this court stated that a defendant could be excused from complying with certain vehicle safety equipment statutes only if it could not have done so by the exercise of the highest degree of care. The cited authorities for this principle, Ainsworth v. Deutschman, 251 Or 596, 446 P2d 187 (1968), and McConnell v. Herron, 240 Or 486, 402 P2d 726 (1965), were in this respect overruled in Freund v. De-*436Buse, 264 Or 447, 451, 506 P2d 491, 493 (1973). Plaintiff’s requested instruction was incorrect as a matter of law because it permitted the jury to find that defendant was excused from its statutory duty only if defendant proved that the violation occurred despite the exercise of a degree of care higher than that of a reasonable man. Freund v. DeBuse, supra. The trial court gave other more accurate instructions on the law and we are satisfied that this requested instruction was properly refused.
Another assignment of error complains of the court’s refusal to grant plaintiff a directed verdict. Prom our review of the testimony, we find that there was substantial evidence from which the jury could have concluded that the excessive speed, inattention, and intoxication of plaintiff’s decedent caused the accident. See Scott v. Mercer Steel/Edwards Realty, 263 Or 464, 503 P2d 1242 (1972) (trial court properly denied defendant’s motion for directed verdict where jury could have found that the accident was the result of defendant’s negligence).
Two assignments of error complain of the court’s jury instructions based on OES 483.992 (2) and 483.999 (1).
The court instructed the jury relating to intoxication, based on OES 483.642 (1) (c) and 483.999 (1),② and that a violation of such law is negligence.
*437Plaintiff registered the following objection to the instructions (although not set forth in the brief pursuant to Rule 2.35, Appendix B, Illustration 5):
“MR. HAWKINS: We also except to the Court’s giving the instruction about .15 being a disputable presumption of negligence in that that statute is criminal in nature and it is only applicable when you take them in conjunction with the requirement set forth in 483.634 through 483.684. It’s not to be given in a civil case.”
We will assume for purposes of this appeal that counsel’s exception was addressed to the jury instruction based on ORS 483.999 (1).
The trial court’s instruction was not erroneous because ORS 483.999 is “criminal in nature” or because it provides for a criminal penalty. Statutes which are criminal in nature frequently provide the basis for civil liability. See Morris, The Relation of Criminal Statutes to Tort Liability, 46 Harv L Rev 453 (1933); Lowndes, Civil Liability Created by Criminal Legislation, 16 Minn L Rev 361 (1932). The presence of a penalty provision in the statute has no effect on liability for negligence unless it can be said that the *438provision was intended to preclude civil liability. Restatement (Second) of Torts § 287 (1965). We find nothing in ORS 483.999 which conveys such a legislative intent.
Prosser states that a violation of a statute may justify the imposition of civil liability when the court determines that the statute is “designed to protect the class of persons in which plaintiff is included, against the risk of the type of harm which has in fact occurred as a result of its violation * * W. Prosser, Law of Torts 200 (4th ed 1971). ORS 483.999 was designed not only to impose certain criminal penalties on convicted violators, but also to declare that the described conduct is dangerous to other drivers and pedestrians using the highway.
The final assignment of error relates to the refusal of the court to instruct the jury on defendant’s failure to equip the log loader with a rearview mirror in conjunction with the specification of lookout. As we have already ruled, the jury could not have found this statutory violation to be a contributing, cause of the accident. Therefore, the court’s ruling was not erroneous and could not have been prejudicial.
Defendant cross-appeals, contending that the jury should not have been permitted to disbelieve uncontradicted evidence that defendant had suffered damages to its log loader in the amount of $8,801.11. The jury had answered Question No. 5 of the Special Findings of Pact as follows:
“What sum of money will fairly and reasonably compensate Kdnzua Corporation for damages to its log loader?
Answer: $_0,00”
Mr. Williams, manager of the repair firm, testified that *439Ms company received the damaged log loader from defendant several days after the accident with instructions to repair it. Williams testified without contradiction that Ms firm performed repairs on the loader for wMch it charged the reasonable sum of $8,801.11.
Defendant contends that the jury should not have been permitted to disbelieve tMs testimony, relying on Rickard v. Ellis, 230 Or 46, 368 P2d 396 (1962). We do not get to the point of applying Rickard v. Ellis, supra. Oregon follows the general rule that the measure of damage to personal property is diminution <of value or “ * * the difference between its value at the place immediately before and immediately after the injury.’ Hansen v. Oregon-Wash. R. & N. Co., 97 Or 190, 201, 188 P 963, 191 P 655 (1920).” Mock v. Terry, 251 Or 511, 512, 446 P2d 514 (1968). The court instructed the jury concerning tMs basic rule.
Mr. Williams was not familiar with the condition of the log loader before the collision. He first saw it when it was brought to the shop for repair. He testified:
“Q And, in your opinion, would the log loader be depreciated in at least that amount [$8,801.11] ?
“A From the new price, probably, yes.”
At the time of the accident the log loader had approximately 9,103 hours of operation and thus may have required some of the accomplished work notwithstanding the collision. It is common knowledge that in the loading and unloading of log trucks and trailers the normal wear and tear to loading equipment can be substantial. Mr. Williams did not testify that all of the repair work wMch Ms firm performed was necessitated by the accident involved herein. Thus, it appears that Williams’s testimony was probative of the cost of repairs but not on the issue of diminution of value.
*440We do not know how the jury arrived at that portion of its finding showing that “$0.00” would reasonably compensate the defendant.
The testimony that the repairs were necessitated by the collision is opinion testimony by an expert. In City of Portland v. Ruggero, 231 Or 624, 630, 373 P2d 970 (1962), we stated the general rule:
“It is not the rule, however, that the trier of the facts is bound by the opinion evidence of experts, even though it be uneontradieted. As we said in Paine v. Meier & Frank Co., 146 Or 40, 44, 27 P2d 315, 29 P2d 531:
“ ‘The probative weight to be accorded to the estimates of witnesses as to rental value and depreciation was a matter entirely for the jury.’ ”
Defendant bore the burden of proving its recoverable damages. In light of the failure of proof on the question of diminution of value, the jury was justified in returning a verdict of zero damages on defendant’s counterclaim. We find no error in this respect.
Affirmed.
Unfortunately, Schwarzin’s deposition is not a part of the record on appeal.
ORS 483.642 (1) (c):
“(1) At the trial of any civil or criminal action, suit or proceeding arising out of the acts committed by a person driving a motor vehicle while under the influence of intoxicating liquor, the amount of alcohol in the person’s blood at the time alleged as shown by chemical analysis of the personas *437breath, blood, urine or saliva shall give rise to the following presumptions:
“(c) Not less than .10 percent by weight of alcohol in his blood, supports a disputable presumption that he was then under the influence of intoxicating liquor.
ORS 483.999 (1):
“(1) Any person who drives any vehicle upon any highway of this state when that person has .15 percent or more by weight of alcohol in his blood as shown by chemical analysis of the person's breath, blood, urine or saliva * * * shall be punished, upon conviction * * *.
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