Evaluation of preventing rear-end collision system

This study was intended to construct and then evaluate rear-end collision preventing systems that support braking operation process of the following vehicle's driver in an attempt to prevent rear-end vehicle collision. The system provides the following vehicle's driver with visual information consisting of three components, an area of red brake lamp in proportion to the degree of the deceleration of own vehicle, an area of red brake lamp in proportion to the degree of the deceleration rate required for the following vehicle, and warning signal by blinking lamp. Using the driving simulator in this experiment, braking operations of the following vehicle's driver taken in response to the braking maneuver of the leading vehicle with the rear-end collision system on board were measured. As a result, in the experiment of the system to provide signals calling for the necessary deceleration efforts, the headway distance between the two vehicles was set at 20 m with 7 m/s² of deceleration velocity, it was found that the braking operation started faster by 0.1 s∼0.2 s and the relative velocity was reduced by about 30%, thus leading to improvement of about 60% in operation of preventing the rear-end collision compared with the vehicle with no such system on board. It is considered that the improved effect resulted from the fact that recognition and judgment of the drivers in the braking operation were supported by the system.