Under the state and municipal highway defect statutes, a person injured by a defective road or sidewalk in Connecticutmust prove that the defect was the “sole proximate cause” of the injury in order to recover against the state or municipality. The problem with the sole proximate cause standard is that is impossibly confusing for juries to apply and makes little sense from a jurisprudential perspective. It’s time to replace sole proximate cause with a standard that both makes sense and achieves the policy goal of limiting the state’s overall liability for highway maintenance.

The sole proximate cause standard is actually a judicial gloss on the state and municipal highway defect statutes, neither of which contains the words “sole proximate cause.” But this judicial interpretation has enjoyed 100 or so years of legislative acquiescence and has become the law of the land for better or for worse. The judicial reasoning behind the “sole proximate cause” rule is set forth most cogently in the Connecticut Supreme Court case of White v. Burns, 213 Conn. 307 1197 (1990). The court reasons the highway defect statutes are meant to provide a cause of action where an injury is caused by a highway defect. If the conduct of the driver or any third party is a substantial factor in causing the injury, the court reasons, the injury cannot truly be “caused” by the defect. Hence, the requirement that the defect be the “sole proximate cause” of the injury.

The problem with this reasoning is that nowhere else in tort law does the law apply such a binary concept of causation. Juries in negligence cases, for example, are instructed completely differently. They are instructed that “negligent conduct can be a proximate cause of an injury if it is not the only cause, or even the most significant cause of the injury, provided it contributes materially to the production of the injury, and thus is a substantial factor in bringing it about.” (See Connecticut Pattern Jury Instructions: 3.1-5 Proximate Cause—Multiple Causes.)

The law should recognize that an accident can have multiple causes and that most accidents cannot be traced to a single substantial factor. Every accident has myriad “but-for” causes and in almost every case a handful of these will turn out to be “substantial” factors leading to the accident. The existence of multiple causes is a concept that makes sense to juries and juries readily grasp the concept of apportionment of fault based on causation. Accordingly, a system that takes into account the typical existence of multiple causes will better comport with reality and be easier for a jury to understand. The concept of “sole proximate cause,” on the other hand, is a legal fiction divorced from the reality of everyday experience and difficult for juries to grasp.

From a policy perspective, whether or not an accident caused in part by a highway defects has an additional unrelated cause is largely a matter of luck. Therefore, the existence of an additional cause is not a good way to distinguish between meritorious and un-meritorious highway defect claims. Consider the hypothetical case of a drawbridge that breaks and has to be left up overnight. The person in charge of closing the gates to warn oncoming drivers neglects to close the gates. An automobile proceeds down the road and off the drawbridge plunging into the river killing four occupants. The driver noticed the bridge was up in time to stop the car, but the brakes malfunctioned because of negligence by the repair shop. If the brakes had been working properly or the drawbridge had been closed, the accident would not have happened.

Under this hypothetical, the state would have no liability because the raised drawbridge was not the sole proximate cause of the accident. But is an unmarked drop into a river not a defect in the roadway? Does the fact that the car that went into the river had bad brakes absolve the state in any way for creating a dangerous condition on the road? This is a classic case where both parties are at fault and both parties should pay a proportionate share of the damages.

If the policy goal is to limit the liability of the state for maintaining roadways, there are better ways to accomplish this task. Instead of focusing on the causation standard (which really should be consistent across all torts) it would be better to focus on the liability standard. The state could be liable only for gross negligence, recklessness, or even intentional conduct. This would have the same effect of limiting claims (and could limit them even more potentially) but it would abandon the legal fiction that any accident can be said to have a single cause or that the number of causes should somehow matter in assessing fault. •