Abstract
Vehicle-infrastructure cooperative safe driving support systems have been introducing into road traffic situation in some countires. Human machine interfaces are a key issue to adequately inform drivers of messages about the dangerous situation where they can not see physically. This research was aimed to suggest some ideas of designing better visual and auditory displays of the messages from the systems. The driving simulator experiments had been carried out ot accomplish this aim. The results had shown that when the drivers' vehicle was running, letters or figures added to letters were better visual displays to inform drivers of invisible dangerous situation than moving image. On the other hands, when driver's vehicle was stopping for turning right, moving image was also good visual desplay. The voice message of invisible dangerous situation was able to make good impressio non drivers when the message was given them on their vehicle running and there was longer time to avoid a crash. According to those results, it is necessary to consider the traffic situation where a system works in order to design better visual and auditory displays informing drivers of invisible dangerous situation from the systems.
