Why do drivers brake later than AEB in rear-end collisions? An analysis based on drive recorder videos
通过重建52起真实出租车追尾碰撞，比较驾驶员与AEB的刹车时机，发现驾驶员刹车更晚的主因是碰撞前未保持向前注视，尤其在低速或红灯等非紧急情况下容易分心。
Rear-end collisions are among the most common crash types in Japan. However, due to their relatively low fatality and injury severity, research on them remains limited. Although previous studies have shown the effectiveness of autonomous emergency braking (AEB), further studies is needed to improve understanding of driver-related factors and enhance system performance to reduce collision risk. This study investigated the effectiveness of AEB and explored factors contributing to braking delays by reconstructing 52 real-world taxi collisions exceeding 10 km/h using PC-Crash. Simulations were conducted with time-to-collision (TTC) and TTC 2nd -based (considering relative deceleration) AEB to evaluate collision-avoidance performance. Additionally, a decision tree was used to examine environmental, vehicular, and human factors affecting the time difference between driver-initiated braking and AEB activation. The result indicates that AEB installed in taxis effectively reduced rear-end collisions. TTC 2nd -based AEB could avoid more collisions involving decelerating lead vehicles. Reducing AEB delay times could further enhance prevention. However, the AEB simulation showed limited effectiveness in collisions involving high speeds, wet roads, or sudden deceleration of the lead vehicle. Moreover, the primary reason drivers braked later than the simulated AEB was their failure to maintain a forward gaze before collisions. Drivers were more likely to divert their gaze from forward driving-related areas in non-critical situations, such as low-speed driving or red traffic signals ahead. This study provides quantitative insights into human factors and AEB technology, which may inform the optimization of AEB systems and the development of driver monitoring systems, contributing to collision prevention and traffic safety.