
331 S.E.2d 695 (1985)
Garland E. HARRIS, Administrator of the Estate of Floriene T. Harris, Plaintiff,
v.
SCOTLAND NECK RESCUE SQUAD, INC. and William Kenneth Baker, Defendants and Third-Party Plaintiffs,
v.
Ben Bell HARRIS, Incompetent, By and Through his guardian ad litem, Jesse B. BULLOCK, Third-Party Defendant.
SCOTLAND NECK RESCUE SQUAD, INC., Plaintiff,
v.
Ben Bell HARRIS, Defendant.
William Kenneth BAKER, Plaintiff,
v.
Ben Bell HARRIS, Defendant.
No. 843SC1105.
Court of Appeals of North Carolina.
July 2, 1985.
Review Denied, Supersedeas and Temporary Stay Denied August 13, 1985.
*698 Blount & White by Marvin Blount, Jr., and Charles Ellis, Greenville, for plaintiff-appellee.
Morris, Rochelle, Duke & Braswell, P.A. by Thomas H. Morris and Edwin M. Braswell, Jr., Kinston, for appellants.
WHICHARD, Judge.
This action arises out of a collision at an intersection between an ambulance owned by Scotland Neck Rescue Squad (Rescue Squad), which was being driven by William Kenneth Baker (Baker), and a passenger vehicle driven by Ben Bell Harris (Harris), the husband of plaintiff's decedent. Plaintiff's decedent, who died from injuries sustained in the collision, was riding in the passenger vehicle.
The jury found both drivers negligent and awarded plaintiff $500,000 which the court reduced to $323,333 under the negligent beneficiary rule, by which plaintiff's decedent's husband, as a beneficiary found negligent by the jury, is precluded from recovery. Rescue Squad and Baker appeal. We find no prejudicial error.

Evidentiary Issues
Appellants contend they were prejudiced when the court allowed plaintiff to examine their expert in audiology on voir dire. They argue that the voir dire enabled plaintiff to depose the witness and thereby avoid eliciting potentially harmful answers on cross-examination. There is no merit to this contention. The audiology expert intended to testify as to the results of an experiment. Before he could do so the court needed to determine in its discretion whether the experiment satisfied the requirements of Mintz v. R.R., 236 N.C. 109, 114-15, 72 S.E.2d 38, 43 (1952) (the experiment must be made under conditions substantially similar to those prevailing at the time of the occurrence involved in the action and the result of the experiment must have a legitimate tendency to prove or disprove an issue arising out of such occurrence). See also Lea Co. v. Board of Transportation, 57 N.C.App. 392, 400-01, 291 S.E.2d 844, 850 (1982), affirmed, 308 N.C. 603, 304 S.E.2d 164 (1983). Thus the court properly allowed voir dire.
Appellants contend the court erred in permitting Baker to be cross examined as to how far south of the intersection he stopped the ambulance, illustrating his testimony with a diagram where one inch equalled twenty feet. Appellants argue that no evidence was introduced concerning the accuracy of the scale of the diagram. This contention is without merit. First, appellants incorrectly assign this error to testimony of Baker when the record shows that the testimony is actually that of Susan Edwards. Second, the evidence elicited on cross-examination was within the scope of the witness' testimony on direct examination. Third, the diagram was properly used to illustrate her testimony. We find no abuse of the court's discretion in admitting this testimony. 1 Brandis, North Carolina Evidence Sec. 42 at 162-63 (2d Revised Edition 1982); see also State v. *699 Bumper, 275 N.C. 670, 674, 170 S.E.2d 457, 460 (1969).
Appellants contend the court erred by not limiting plaintiff's cross-examination of Baker. We find that the court acted within its discretion. See McCorkle v. Beatty, 226 N.C. 338, 341-42, 38 S.E.2d 102, 105 (1946); see also Bumper, 275 N.C. at 674, 170 S.E.2d at 460.
Appellants contend the court erred in admitting the testimony of Gary Davis, a witness who stated that he saw the ambulance run a red light at a high rate of speed without its yelper on at the intersection immediately prior to the scene of the collision. Appellants argue that this testimony falls within the rule that evidence of acts of negligence on prior unrelated occasions is not competent to prove a driver's negligence on the present occasion. Mason v. Gillikin, 256 N.C. 527, 532, 124 S.E.2d 537, 540 (1962). We disagree that the evidence falls within this rule. Davis' testimony was as to Baker's negligence on this occasion, not a prior occasion. In addition, Baker testified that he was driving forty-five miles per hour, slowed to thirty miles per hour as he reached the intersection before the one at which the collision occurred, and put on his yelper at that point. The testimony of Davis was thus properly offered in rebuttal to impeach Baker by evidence of conduct inconsistent with his testimony at trial. 1 Brandis, supra, Sec. 46 at 176.
Appellants contend the court erred in allowing William Eakes, an eyewitness, to testify that he had observed other ambulances pass through the intersection where the collision occurred and that the court erred in stating in response to appellants' objection to this testimony, "It's certainly a permissible subject." Appellants' first assignment of error as to Eakes' testimony is overruled for two reasons: appellants opened the door to this line of questioning by eliciting testimony from Eakes concerning other ambulances and whether their sirens were on; and the evidence was relevant to show the standard of care to which Baker should have conformed when travelling through the intersection. Brandis, supra, Sec. 89 at 335. See, e.g., Fox v. Texas Co., 180 N.C. 543, 545-46, 105 S.E. 437, 438 (1920) (evidence that a similar accident was avoided by ordinary care admissible to show want of care); Murdock v. R.R., 159 N.C. 131, 74 S.E. 887 (1912) (plaintiff in negligence action allowed to testify as to care exercised by other railroads). Appellants second assignment of error as to the court's comment is also without merit. The testimony was admissible and there was no prejudice to appellants in the court saying so.
Appellants contend the court erred in admitting testimony of an investigating officer that he examined the traffic signal the afternoon of the accident and "could not determine any malfunction in the lights." Appellants' objection may not have been timely since it was not made until after the officer had answered the question asking him the result of his checking. Medford v. Davis, 62 N.C.App. 308, 310, 302 S.E.2d 838, 840, disc. rev. denied, 309 N.C. 461, 307 S.E.2d 365 (1983). Assuming, arguendo, that the objection was timely, we find the testimony admissible: as a fact within the officer's knowledge; as a permissible shorthand statement of a fact impractical to describe in detail, id; and as a statement which was "not an opinion on the ultimate issue to be decided by the jury." Id. This assignment of error is thus overruled.
Without citing authority, appellants contend the court erred in allowing a witness who maintained and installed traffic signals to testify that he had received no complaints about the light at the intersection where the collision occurred. We find that the witness was competent to so testify and that the evidence was admissible. See 1 Brandis, supra, Sec. 82.
Appellants assign as error the court's admission of several photographs as substantive rather than illustrative evidence. They cite no authority for their position. They do not argue that the photographs are inflammatory and do not include *700 the photographs as exhibits. It appears from the record that a proper foundation was laid for introducing the photographs as either illustrative or substantive evidence. G.S. 8-97 (effective 1 October 1981). Moreover, appellants have failed to show prejudice. This assignment of error is therefore overruled.
Appellants contend the court erred in permitting plaintiff to ask certain leading questions. Appellants have not shown prejudice therefrom and we find no abuse of discretion by the court. This assignment of error is without merit.

Jury Instructions
At trial appellants sought to prove that the negligence of Harris was the sole proximate cause of the collision. To that end they offered testimony as to the condition and value of the ambulance, the location of the siren, and the distance over which it would be audible. Without citing authority, appellants assign as error the court's instruction that this evidence related to Harris but did not relate to plaintiff's decedent. We find the instruction proper. Since no claim of contributory negligence was asserted against plaintiff's decedent, evidence as to the value of the ambulance, the location of the siren, or the distance over which the siren could be heard could not be relevant as to her. We do not believe the instruction precluded the jury from finding that Harris' negligence was the sole proximate cause of the accident.
Appellants assign error to the court's instruction on the negligent beneficiary rule and its application in this case. Since appellants did not object at trial, however, they may not now object on appeal. N.C. Rules of Appellate Procedure, Rule 10(b)(2). Contrary to appellants' contention, the plain error rule, State v. Odom, 307 N.C. 655, 659, 300 S.E.2d 375, (1983), is not applicable in a civil case. Durham v. Quincy Mutual Fire Ins. Co., 311 N.C. 361, 367, 317 S.E.2d 372, 377 (1984). This assignment of error is thus without merit.
Appellants' contention that they were prejudiced by the court's failure to conduct a charge conference pursuant to Rule 21 of the General Rules of Practice for the Superior and District Courts is also without merit. The record clearly reveals that the court complied with the rule.

Motions
Appellants assign error to the court's failure to conduct further inquiry into "a conversation between plaintiff and [a] juror." As plaintiff notes and the record shows, however, the alleged conversation was not between a party and a juror but was a conversation concerning collateral matters between parties and witnesses in the presence of jurors. Further, appellants did not move for a mistrial and on the record expressed satisfaction with the court's handling of the matter. We find no authority, and appellants cite none, that imposes a duty on the court in this situation to conduct further inquiry or declare a mistrial ex mero motu. For the same reasons we find no merit in appellants' contention that the court erred in failing to declare a mistrial ex mero motu when informed by plaintiff's counsel that he had early on cautioned his clients not to speak to jurors. Appellants misread this cautionary remark by plaintiff's counsel as an admission that actual conversations between clients and witnesses took place. That they did not is clear from the record.
Appellants contend the court erred in denying their motions to set aside the verdict, for judgment notwithstanding the verdict, and for a new trial. Each motion was made on the grounds that the damages awarded were excessive. Appellants argue that because plaintiff's decedent was seventy-five years old at the time of death, the award of $323,333 to her two adult sons was in excess of the value of the loss of her services, protection, society, comfort, and guidance. Citing Worthington v. Bynum, 305 N.C. 478, 290 S.E.2d 599 (1982), appellants contend the court's denial of their motions to set aside the verdict and for a new trial amounts to a "substantial miscarriage of justice."
*701 In reviewing a trial court's discretionary ruling either granting or denying a motion to set aside the verdict and order a new trial, we are virtually prohibited from intervening, Pearce v. Fletcher, 328 S.E.2d 889, 890 (N.C.App.1985); appellate review "is strictly limited to the determination of whether the record affirmatively demonstrates a manifest abuse of discretion by the judge." Id. citing Worthington, 305 N.C. at 482, 290 S.E.2d at 602. After a careful review of the record we find no such manifest abuse of discretion. We also find that the evidence viewed in the light most favorable to plaintiff was sufficient to sustain the verdict, Investment Properties v. Allen, 281 N.C. 174, 184-85, 188 S.E.2d 441, 447-48 (1972), and that, therefore, the court properly denied appellants' motion for judgment notwithstanding the verdict.

Prejudgment Interest
Appellants contend the court erred by allowing prejudgment interest since G.S. 24-5 permits such only on claims covered by liability insurance and plaintiff presented no evidence that Rescue Squad carried liability insurance covering this claim. We do not believe G.S. 24-5 requires plaintiff to present such evidence. Indeed, the law prohibits plaintiff from introducing such evidence at trial. Fincher v. Rhyne, 266 N.C. 64, 145 S.E.2d 316 (1965) (evidence of liability insurance is prejudicial and entitles movant to a new trial); Lytton v. Manufacturing Co., 157 N.C. 331, 72 S.E. 1055 (1911). In light of the statutory requirement of financial responsibility, G.S. 20-309 et seq., which is generally met through liability insurance, we hold that defendant had the burden of showing the absence of such insurance. The record reveals no presentation of evidence or statement to the trial court indicating that Rescue Squad does not have liability insurance covering this claim. Appellants have not asserted the absence of liability insurance in their brief in this Court; at oral argument counsel for appellants, upon specific questioning, declined to state that Rescue Squad is not so covered. This assignment of error is therefore overruled.
Appellants contend the court erred in allowing prejudgment interest for the period prior to the time they were served with a valid complaint. G.S. 24-5 allows prejudgment interest to accrue "from the time the action is instituted." G.S. 1A-1, Rule 3 provides, that "[a] civil action is commenced by filing a complaint with the court." Here plaintiff filed his complaint on 4 June 1982. Thus the action was instituted on 4 June 1982 and the court properly allowed prejudgment interest to accrue from that time.
Appellants contend that G.S. 24-5 violates Art. I, Sections 19 and 32 of the North Carolina Constitution and the equal protection and due process clauses of the Fourteenth Amendment to the United States Constitution. Our Supreme Court has resolved these arguments adversely to appellants in Lowe v. Tarble, 312 N.C. 467, 323 S.E.2d 19 (1984) and Powe v. Odell, 312 N.C. 410, 322 S.E.2d 762 (1984).
We conclude that this trial was free from prejudicial error and that judgment was properly entered for plaintiff.
No error.
HEDRICK, C.J., and WEBB, J., concur.
