Analysis of Drivers' Behavior in Longitudinal Direction Based on A Performance Index for Approach and Alienation

A performance index for approach and alienation that estimates driver's status such as inattentive operation from the vehicles behavior as a result of the driver's visual cognition, judgment, and operation have been proposed to prevent rear-end crashes. The index is based on the hypothesis that drivers are performing approach detection and deciding braking behavior with change of area of a preceding car on the retina. Based on the index, braking behaviors in preceding-car-following situation is analyzed. The experimental results of a test driver with a real car with constant relative velocity to preceding car show that the braking behaviors can be characterized using the index and headway distance. In addition, the results of laboratory experiments using a driving simulator support the results of the real car experiments. We conclude that the drivers' deceleration behavior in moderate danger levels can be characterized well in a plane of the proposed index and the headway distance.