The sole issue before us is whether the trial court properly granted summary judgment for defendants Harze and Nu-Car Carriers, Inc., which dismissed with prejudice the plaintiffs claims against these defendants. We hold that the trial court erred in granting these defendants’ motions for summary judgment.
Generally, issues arising in a negligence case are not susceptible to summary adjudication. Moore v. Fieldcrest Mills, Inc., 296 N.C. 467, 251 S.E. 2d 419 (1979). “It is only in exceptional negligence cases that summary judgment is appropriate. (Citations omitted.) This is so because the rule of a prudent man (or other applicable standard of care) must be applied, and ordinarily the jury should apply it under appropriate instructions from the Court.” Page v. Sloan, 281 N.C. 697, 706, 190 S.E. 2d 189, 194 (1972). In this case, as in all summary adjudications, the moving party may prevail upon his motion only if he establishes that there is no triable issue of fact. Page v. Sloan, 281 N.C. 697, 190 S.E. 2d 189 (1972). In addition, factual inferences arising from the evidence must be drawn against the moving party. Caldwell v. Deese, 288 N.C. 375, 218 S.E. 2d 379 (1975). In the case sub judice there is a triable issue of fact as to the proximate cause of the collision and the resulting injury to the plaintiff.
The facts of this case reveal the presence of two negligent groups, (1) defendant Harze and his employer, defendant Nu-Car Carriers, Inc. and (2) defendant Allred. When the defendant Harze parked the truck owned by Nu-Car Carriers, Inc., on the portion of the highway used for travel without displaying any lights or flares whatsoever he violated G.S. 20-134 which is negligence per se. Barrier v. Thomas and Howard Co., 205 N.C. 425, 171 S.E. 626 (1933). In addition it is a violation of G.S. 20-161(a), to leave a vehicle on the main traveled portion of the highway beyond municipal corporate limits unless it is impossible to move the vehicle due to a breakdown. Defendant Harze also violated G.S. 20-161(a) and such violation is negligence per se. Hughes v. Vestal, 264 N.C. 500, 142 S.E. 2d 361 (1965). The negligence of defendant Harze is imputed to defendant Nu-Car Carriers, Inc., since agency is admitted in the pleadings. Jackson v. Mauney, 260 N.C. 388, 132 S.E. 2d 899 (1963); Dowdy v. R.R., 237 N.C. 519, 75 S.E. 2d 639 (1953). The *116second negligent party in this case is defendant Allred who admits to driving her vehicle while under the influence of intoxicants which prevented her from operating the automobile in a careful and prudent manner. This act is negligence per se. Watters v. Parrish, 252 N.C. 787, 115 S.E. 2d 1 (1960).
Conceding that both sets of defendants were negligent per se in their actions, the Court of Appeals held, as did the trial court, that the negligence of defendant Allred was the sole proximate cause of the collision and thereby insulated from liability the negligence of defendants Harze and Nu-Car Carriers, Inc. In short, the Court of Appeals held that no collision would have occurred but for the negligence of defendant Allred. The doctrine of insulating negligence and the criteria for determining its application apparently is composed of two tests. In the first test the court views the collision from the position of the original negligent actor. Chief Justice Stacy noted in Butner v. Spease, 217 N.C. 82, 6 S.E. 2d 808 (1940) that, “[t]he test by which the negligent conduct of one is to be insulated as a matter of law by the independent negligent act of another, is reasonable unforeseeability on the part of the original actor of the subsequent intervening act and resultant injury.” 217 at 89, 6 S.E. 2d at 812. In the second test the Court views the collision from the position of the second or intervening negligent party. In Powers v. Sternberg, 213 N.C. 41, 195 S.E. 88 (1938) Chief Justice Stacy said, in citing Kline v. Moyer, 325 Pa. 357, 191 A. 43 (1937), as setting out a practical statement of the rule of insulating negligence that, “ ‘where a second actor has become aware of the existence of a potential danger created by the negligence of an original tortfeasor, and thereafter, by an independent act of negligence, brings about an accident, the first tort-feasor is relieved of liability because the condition created by him was merely a circumstance of the accident and not its proximate cause.’ ” 213 N.C. at 44, 195 S.E. at 90.
Although this Court has applied two distinct tests for determining whether the negligence of one party should be excused because of the intervening negligence of another, there is a common thread which weaves its way through both of Chief Justice Stacy’s comments on the doctrine of insulating negligence. The question is not when should the second actor carry the entire burden but when should the first actor be totally relieved of all *117liability. The common thread in these two tests is foreseeability. Under the first test as set out in Butner v. Spease, supra, the first actor is relieved of all liability because he could not be expected to foresee the subsequent intervening negligent act and resulting injury. Under the second test set out in Powers v. Sternberg, supra, the first actor is free of liability because, he could not be expected to foresee that the second actor would ignore the dangerous conditions created by the first actor.
In the case sub judice the original negligent party, Harze, personally could have foreseen the negligence of the defendant Allred and the resultant collision. Likewise, there is nothing in the record which suggests that the defendant Allred became aware of the dangerous conditions created by the negligence of defendant Harze in time to avoid the accident. In Powers v. Sternberg, 213 N.C. 41, 195 S.E. 88 (1938) Chief Justice Stacy, in citing Kline v. Moyer, supra, stated, “ ‘where, however, the second actor does not become apprised of such danger until his own negligence, added to that of the existing perilous condition, has made the accident inevitable, the negligent acts of the two tortfeasors are contributing causes. . . .’ ” 213 N.C. at 44, 195 S.E. at 90. The evidence presented before the trial court in this case does not resolve a crucial question of fact, to-wit, whether a reasonable and prudent person traveling south along rural road 1419 at 2:30 a.m., who encountered an approaching vehicle with bright lights, would have observed the unlighted truck in time to avoid colliding with it. The question of what was the proximate cause of the collision can be decided in one of three ways under the facts in this case: (1) that the negligence of defendant Allred was the sole proximate cause, (2) that the negligence of defendant Harze was the sole proximate cause and (3) that the negligence of all the defendants combined and were contributing proximate causes of the collision.
It is not enough to establish liability if all that can be shown is that an actor was negligent. There must be a showing or determination of proximate cause. Justice, later Chief Justice, Sharp wrote in Atkins v. Moye, 277 N.C. 179, 176 S.E. 2d 789 (1970) that, “unquestionably a motorist is guilty of negligence if he operates a motor vehicle on the highway while under the influence of intoxicating liquor. Such conduct, however, will not constitute either actionable negligence or contributory negligence unless —like any *118other negligence — it is causally related to the accident. Mere proof that a motorist involved in a collision was under the influence of an intoxicant at the time does not establish a causal relation between his condition and the collision.” (Citations omitted.) 277 N.C. at 186, 176 S.E. 2d at 794. Even though a motorist must exercise ordinary care when driving at night, the doctrine of insulating negligence was “not designed to require infallibility of the nocturnal motorist, or to preclude him from recovery of compensation for an injury occasioned by collision with an unlighted obstruction whose presence on the highway is not disclosed by his own headlights or by other available lights.” Speaking through Justice Ervin in Thomas v. Motor Lines, 230 N.C. 122, 132, 52 S.E. 2d 377, 383-384 (1949).
Under the facts of this case we cannot say as a matter of law that the negligence of the defendant Allred was the sole proximate cause of the collision which resulted in injury to the plaintiff. The statements made by defendant Allred clearly establishes that she was negligent in operating her automobile. Ms. Allred’s affidavit states in part:
(A)t the time of the accident, I was under the influence of intoxicants and I did not see the truck in time to avoid colliding with it; . . . Just before the accident, this affiant was intoxicated to the extent that she was unable to operate an automobile in a careful and prudent manner or keep it under proper control.
Although this statement settles the issue of her negligence it does not determine as a matter of law the causal relationship between her negligence and the accident. The facts simply do not preclude a finding by the jury that the defendants’, Harze and Nu-Car Carriers, Inc., negligence was a proximate cause or the sole proximate cause of the collision. For these reasons summary judgment was not proper in this case.
We, therefore, reverse the ruling of the Court of Appeals and remand this case to that court for remand to Superior Court, Guilford County for trial.
Reversed and remanded.