Sometimes the black letter law passed by the legislature is unclear. The legislature can’t anticipate every possible fact scenario when they pass a law, so it lay to the courts to interpret the law and give guidance to what it means. This interpretation is called case law. When the court decides a certain meeting to the law it essentially answers a legal question. Lawyers and other courts then can rely on that ruling when they have a similar issue in their case. The following case answers the question above.

Condos v. Associated Transports, Inc., 453 S.W.2d 682 (Mo. Ct. App. 1970).

This case addresses the following issue:

When can the violation of a law be used to establish a claim of negligence per se?

In this case, the court was asked to determine when the violation of a traffic statute can constitute a claim of negligence per se. Id. at 685. A claim for negligence per se involves the violation of a statute to establish a breach of a duty by a defendant, and thus, create liability. Id. at 686. The court here determined that, absent “unusual circumstances” that support “deviation from the statutory standard,” violation of a statute will support such a claim so long as the statute was designed to prevent the harm caused to the plaintiff. Id.

Plaintiff was the passenger in a vehicle driving along the highway. Id. at 684. Defendant was operating a semi-truck pulling a trailer. Id. Defendant switched into the left-hand lane in preparation for an upcoming left-hand turn. Id. Defendant also began slowing in anticipation of the turn. Id. This caused the driver of Plaintiff’s vehicle to switch into the right-hand lane to pass the slowing truck. Id. at 685. As the car was passing, the truck veered into the right-hand land to compensate for the left-hand turn. Id. At that point, the truck struck the car, resulting in severe injuries to Plaintiff. Id.

The court began by noting that “a failure to comply with a statute, in the absence of a showing of a reasonable excuse for its non-observance, constitutes negligence per se.” Id. at 686. However, the circumstances of each violation must be considered to determine if “reasonable excuse” exists. Id. Common reasons to excuse violations include emergency conditions, impossibility to comply with the statute, or circumstances that make complying with the statute more dangerous than violating the statute. Id. However, these circumstances are certainly the exceptions, not the rule. Id.

In this case, the truck driver’s need to slightly enter the right-hand lane to complete the left-hand turn did not constitute reasonable excuse. Id. at 687-88. Though this is a necessity for making such a turn for a large vehicle, the driver should have yielded to vehicles in the right-hand lane. Id. at 688. To hold otherwise would be to say that the truck driver is permitted to violate traffic laws anytime doing so would be convenient for him. Id. Instead, drivers of large vehicles must ensure it is safe to justifiably violate such laws and regulations before doing so. Id. Thus, the Plaintiff had a valid claim for negligence per se. Id.