Experienced drivers check the rear view periodically. But drivers who are not confident in driving such as beginners, those who drive on unfamiliar roads such as highways, or those who are tired cannot afford to watch a following vehicle sometimes. So, once they recognize the following vehicle, they may change lanes in a hurry and unsafely without checking the surroundings. On the other hands, aggressive driving is a social problem in the world. Public institutions for traffic safety said it’s a major public concern, published brochure, or tightened the traffic law in Japan, the United States, China, etc. Notification of following vehicle’ approaching at the appropriate timing reduces burden of driver caused by checking the rear view mirror many times. Furthermore, if drivers who cannot afford to watch behind get notification, they can watch the surroundings with time to spare and change the lane safely. On the other hands, regarding aggressive driving, the most common reason why they are harmed is that they block the way of the following vehicle. So, to prevent encountering aggressive driving, they need to recognize the following vehicle and give way. According to the survey results, we proposed a system that inform a driver of its approaching and advise them to judge whether it is necessary to change the lane or not when the following vehicle is approaching. The millimeter-wave radar sensors which are installed at the rear sides of the vehicle detect the following vehicle and notify driver by meter display. In order to verify the usefulness of the proposed system based on the analysis described above, we conducted actual vehicle’ test, which having them actually encountered rear vehicle’ approaching on a test course. We had 47 test subjects experience the conditions by using the actual vehicle with the system configuration described above. As a result, 94% of the 47 subjects answered that it was useful. We found that the proposed system would be useful. These objectives are common in the world but this verification by actual vehicle focuses on the Japanese region firstly. The verification of other regions should be researched as the future study. As of December 2022, there are drive recorders on the market that is retrofitted to vehicles to detect aggressive driving and record video as an event with notification. But there is nothing that notify driver before they encounter aggressive driving. In addition, there is no technology like this even among vehicle manufacturers. The proposed system is new from the viewpoint of concept, which reducing burden of checking the rear view mirror many times, changing lane safely, and prevent the harm of aggressive driving in case of rear vehicle’ approaching. Based on survey, we proposed and developed a system that inform a driver of its approaching and advise them to judge whether it is necessary to change the lane or not when the following vehicle is approaching. This reduces the burden of driver caused by checking the rear view mirror many times and also helps driver to change lane safely. Furthermore, this contributes to prevent encountering aggressive driving. We found this proposal is beneficial by verification of actual vehicle. This technology is unique from the viewpoint of concept.

Mr. Takahiro Kohara, Senior engineer, TOYOTA MOTOR CORPORATION