Human factors involves the relationship between a person and their environment. In terms of an accident investigation it is used to analyze an individual’s response to a hazard. Vehicular accident reconstruction utilizes human factors to evaluate driver response. There are multiple factors that effect the way a driver responds to a hazard. This includes the type of collision, lighting conditions, weather influences, driver impairment, vehicle configuration, and more. Human factors is often used in accident reconstruction and is necessary for evaluating accident avoidability.