Abstract
It is necessary for drivers to understand current and subsequent mode of driver-support system function adequately in order to prevent the misunderstanding and wrong use of the function. Display interfaces can accurately convey the modes to driver and may lead a driver to understand transitions of the modes adequately. This research aims to investigate each effect of visual and auditory display on driver's understanding of the mode transitions. The results of driving simulator experiment found that it was important to use both visual character and auditory signal simultaneously as to inform a driver of the current mode and increasing possibility of collision, especially when a driver was needed to avoid a collision. In addition, it showed that voice message was available when there were large margins for a driver to avoid collision with lead vehicle. The results suggest necessity of use of both visual and auditory display to inform drivers that it was necessary for them to avoid a collision in emergency situation.
