An Analysis of Elderly drivers' behavior around Accident-Prone Toll Plaza on Expressway

摘要

Although rapid aging of popularity causes serious traffic problem in Japan, only few studies have been conducted to investigate elderly drivers' behavior especially on expressway. Our statistical analysis of accident records on expressway in past five years showed that (1) toll barriers (TBs) are highly accident-prone (2) a typical pattern of elderlies' accidents is significantly different to that of non-elderlies' on TBs; while characteristic pattern of elderlies' accidents is "side-by-side collision caused by drivers' lack of scanning for checking safety of backside", that of non-elderlies' is "rear-end-collision caused by eye glance behavior while driving at TB gate". However, whereas accident records analysis gives us approximate information about elderlies' accidents, it gives us no detailed information about traffic environment or drivers' behavior. Therefore, in this study, to know detailed information about traffic environment on TBs, we analyzed 845 vehicle trajectories on an accident-prone TB using video-based approach and detected potentially dangerous spots where traffic conflicts frequently occur. Then, to know how elderly drivers behave at the detected spots, we performed an experiment in real traffic conditions using 40 subjects (26 elderlies and 14 non-elderlies). In our study, we let each subject drive the expressway including the TB and measured his driving behavior using multiple sensors (eye camera, video camera, etc.). After finished driving, to know how each subject perceived risk while driving, we interviewed each subject by showing videos of his own driving behavior recorded in the experiment. As a behavioral approach, we evaluated and scored each subject's safe driving skill for preventing accidents based on driving instructors' knowledge using measured sensor data. The result of driving behavior evaluation was that elderlies' safe driving skill score at the potentially dangerous spots on the TB is significantly lower than that of non-elderlies'. In addition, to know why elderlies' behave riskily on the TB, we analyzed subjects' interview data and evaluate each subject's risk perception ability (psychological approach). The evaluation result of risk perception ability shows that even at the potentially dangerous spots on the TB where traffic conflicts frequently occur, elderlies' could not perceive risk appropriately.