DEVELOPMENT OF A RISK EVALUATION MODEL FOR REAR END COLLISIONS CONSIDERING THE VARIABILITY OF REACTION TIME AND SENSITIVITY

A model and a measure that can evaluate the risk of rear end collision are developed considering actual driver's behaviors. These behaviors are analyzed on the basis of three concepts - risk, responded risk, and accident - related to accidents. An index that can represent the risk was also developed based on the methods used in evaluating noise level. For risk comparison among various situations, the equivalent risk level with respect to the intensity and duration time is developed. The model was validated with field surveys of the expressway of Seoul using a test vehicle capable of collecting the traffic flow data. Based on these data, the risk by section, lane, and traffic flow conditions was evaluated and compared with the accident data and traffic conditions. The results showed that evaluated risk level corresponds closely to the patterns of actual traffic conditions and number of accident.