oa Characteristics of approach pattern in car and bicycle in Japanese traffic road

Protection of vulnerable road users is important to reduce traffic fatality in Japan. The use of active safety devices that can detect cyclists is considered to be an effective countermeasure for reducing the severity of injuries and number of cyclist fatality. The detailed features of car–cyclist contact scenarios need to be clarified to develop such safety devices. Since there is limited information on real-world accidents, the present study investigates near-miss scenarios captured by drive recorders installed in passenger cars. In this study, we showed the similarities of the contact situations between near-miss car-to-bicycle incidents and real-world fatal cyclist accidents. Then we analyzed video frames of 161 near-miss data when bicycles were crossing the road in front of the forward-moving cars to understand the contact situations between cars and bicycles. Additionally, using a video recorded by a drive recorder, we calculated the estimated collision time from the car velocity and the distance between the car and bicycle. For the definition of the estimated collision time, the worst situation was assumed to be that when a car moved toward a cyclist without the driver realizing the cyclist and braking. The results indicated that the average estimated collision time in the cases where bicycles emerged from behind obstructions was shorter than that in the cases where drivers had unobstructed views of the bicycles. When we consider the estimated collision time in the test protocol of evaluation for safety performance of active safety devices, two scenarios should be employed; bicycle emerged from behind unobstructed views and bicycle emerged from behind obstructions.