Hindsight Judgment of Driver Fault in Traffic Accident Analysis

Abstract

A warning is raised about how the science of traffic accident reconstruction is naively misused by inviting and exacerbating “hindsight bias” when the reasonableness of a driver's unsuccessful attempt to avoid an accident is judged. “Those who know how things turned out have trouble believing others didn't see what was coming.” In highway safety research, where a reliable understanding of the causes of accidents is prerequisite to developing safer roads, hindsight compromises the validity of research results. In the legal arena, where the stakes are high in judgments of fault, hindsight will bias judgments against drivers involved in accidents, especially when there are serious injuries. Researched by cognitive psychologists since the early 1970s, hindsight bias is reviewed within the context of causal analysis and attribution of fault for the typical accident that arises when one driver suddenly interferes with the path of another, demanding evasive action. An example accident reconstruction is presented to demonstrate how science that helps to explain how an accident happened inherently provides an after-the-fact reference for precisely how the reactive driver should not have responded and how she or he could have done better. The typical reconstruction diagram is dubbed a hindsight diagram to emphasize how such graphic designs can bias judgment by illustrating conclusive facts about an accident that did not exist just seconds before, at the time the reactive driver had to respond. Although debiasing techniques, including the concept of a foresight diagram, are discussed, hindsight bias remains a major factor in accident analysis.