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How Perceptual and Cognitive Factors
are Involved in a Car Accident:
A Case Study

By: Vanessa Dominguez & Marc Gentzler | Mentor: Dr. Andrew P. Daire


The United States Department of Transportation indicated that in 2009, more than 33,000 people died in motor vehicle crashes (National Highway Traffic Safety Administration, 2010). The Centers for Disease Control and Prevention (CDC, 2010) identified traffic collisions as one of the leading causes of death in the United States. Approximately 5 million people annually sustain injuries that require an emergency department visit. With all these costs in mind, it is important for professionals, researchers, and engineers working on improving driver safety and motor vehicles to understand what causes car accidents. Furthermore, it is essential for these researchers and practitioners to consider many factors involved in car accidents as possible, including different perceptual and cognitive factors.

Driving is one of the most complex tasks humans perform on a regular basis (Hole, 2007). Driving places significant demands on human perceptual, cognitive, and motor capabilities. Therefore research conducted in human factors is needed on these capabilities while driving. The National Highway Traffic Safety Administration (NHTSA, 2011) defines Human Factors Engineering in general as the "application of knowledge about human abilities, limitations, and other human characteristics to the design of equipment, tasks, and jobs". The role of human factors research is important for understanding human performance and disseminating and applying this knowledge to when humans interact with any system, such as with vehicles. Vehicle safety research recognizes that driver performance is affected by several situational factors such as environment, psychology, and vehicle design. Car accident analysis involves reconstructing several factors that influenced the accident. The Handbook of Human Factors in Litigation (2004) describes perceptual and cognitive factors including driver expectancy (pg. 335), glare (pg. 327), reaction time (pg. 363), visibility (pg. 342), and illusions (pg. 451) that are used to reconstruct car accidents. The following case study analysis explains the possible contribution of different perceptual and cognitive factors involved in a particular car accident: (a) driver expectancy effects, (b) glare, (c) general visibility, (d) driver's dark adaptation, (e) road illusions, and (f) driver perception-reaction time.

Each factor is individually discussed, highlighting its effects on driver performance in general and its possible impact on the accident. Although alcohol, which clearly can affect all aspects of nervous system functioning, played a role in this particular accident, the combined perceptual and cognitive factors mentioned above may be influential enough to cause the accident independent of alcohol influence.

Description of Accident >>