Driver assistance system indicating information on predicted longitudinal maneuver at rear-end of preceding vehicle

This study examines a driver assistance system to predict driving behavior considering information on the pre-preceding vehicle behavior. The authors have defined an anticipation index called PRE3 and proposed a driving assistance system that indicates the PRE3 to the driver in real-time during a car-following. The assistance system indicates the predicted driving evaluation index at the rear-end of the preceding vehicle. The proposed driving assistance system considering the relations not only between the preceding and following vehicles, but also between the pre-preceding and following vehicles. Driving simulator experiments were carried out with eight participants who are required to follow a preceding vehicle and a visible pre-preceding vehicle with and without the driving assistance system. It was found that high acceleration and large speed difference with the preceding vehicle could be eliminated by the proposed system. These effects make it possible to suppress the variation of the collision risk to the preceding vehicle and to reduce fuel consumption of the following vehicle. In addition, the proposed assistance system reduces drivers' reaction time to the emergency deceleration of the preceding vehicle compared with the conventional assistance system, in which PRE3 is indicated at the onboard monitor of the following vehicle. Indicating PRE3 at rear-end of the preceding vehicle helps the driver to decelerate earlier and to avoid the high deceleration.