The purposes ofthis research are the followings: one is to investigate drivers’ behavior and characteristics against the emergency braking of the leading vehicle by the JAR1 driving simulator. The other is to clarity the effectiveness of danger warning ofthe leading vehicle. For this analysis, the experiment using the JAR1 driving simulator was conducted. The virtual leading car on the simulator is controlled automatically and rapidly stops by the trigger command ofa simulator operator. The subjects are 14 males in 20 to 29 ages.
From the experimental data, the di%rence of such variables to be analyzed as brake delay time, mean deceleration and minimum headway distance were compared between in case that the drivers cannot predict the emergency braking and in the case that they can predict it. As a result, those parameters in the unpredictable situation were larger than in the predictable situation.
In order to improve the drivers avoidance characteristics, effectiveness of danger warning against the emergency braking ofthe leading car was examined. The main effect and the interaction of the vehicle velocity, the warning time and the headway time on the variables to be analyzed were clarified by analysis of variance. The result ofthis test showed that the effect of the danger warning was recognized and the danger warning can make compensation for the increase of the brake delay time in the unpredictable situation.