Legal Definitions - Pennsylvania rule

The Pennsylvania rule is a legal principle that primarily applies in cases where an injury occurs (known as a tort). It addresses situations where one party causes an injury while simultaneously violating a safety-related law, statute, or regulation.

Under this rule, if a party is found to have violated a safety statute and an injury occurs, the burden of proof shifts. Instead of the injured party having to prove that the violation *caused* the injury, the party who committed the violation is presumed to have caused the injury. Consequently, the violator must then prove that their violation *did not* contribute to or cause the injury. This is a significant departure from the typical legal standard, where the injured party usually bears the responsibility of proving causation.

Here are some examples to illustrate the Pennsylvania rule:

• Example 1: Traffic Accident

  Imagine a commercial truck driver operating their vehicle with bald tires, which is a violation of state vehicle safety regulations. While driving on a wet highway, the truck hydroplanes and collides with another car, causing significant damage and injuries to the other driver. Under the Pennsylvania rule, because the truck driver was violating a safety statute (operating with unsafe tires) at the time of the accident and injury, the burden would shift. The truck driver (or their company) would then have to prove that the bald tires *did not* contribute to the hydroplaning or the subsequent collision and injuries. They might try to argue, for instance, that the other driver was also speeding excessively, and the accident would have occurred regardless of the tire condition.

• Example 2: Workplace Safety Incident

  Consider a manufacturing plant that fails to properly secure a piece of heavy machinery to the floor, which is a direct violation of federal occupational safety standards. During operation, the unsecured machine vibrates excessively, eventually toppling over and injuring a worker nearby. Applying the Pennsylvania rule, since the plant violated a safety regulation (failing to secure machinery) and an injury resulted, the plant would be presumed responsible. To avoid liability, the plant would need to demonstrate that the failure to secure the machine *did not* cause the machine to fall or the worker's injury. They might attempt to argue that the worker was improperly operating the machine against safety protocols, and that was the true cause of the incident.

• Example 3: Recreational Boating Collision

  Suppose a recreational boater is operating their vessel at night without the legally required navigation lights illuminated, a clear violation of maritime safety regulations. Another boat, unable to see the unlit vessel, collides with it, causing damage to both boats and injuries to passengers on the second boat. The Pennsylvania rule would apply to the boater who failed to display navigation lights. They would be presumed to have caused the collision and injuries. To avoid liability, they would need to affirmatively prove that their failure to have the lights on *did not* contribute to the collision. For example, they might argue that the other boat was traveling at an extremely high speed in a restricted area and was not keeping a proper lookout, making the collision unavoidable even if their lights had been on.