Experimental study on car collisions with bicycles equipped with child seats.

In Japan, traffic accidents involving bicycles have become a serious problem as a result of the increase in the use of bicycles due to the rising concerns of environmental and health problems. In recent years, bicycles equipped with child seats have become a popular means of transportation for preschool children in urban areas in Japan. Under such adverse circumstances, it is necessary to conduct more studies and evaluations to prevent traffic accidents and the resulting injuries involving bicycles with children. For accident prevention and damage mitigation, this study mainly aims to understand the kinematic behavior and injury risk of children in collisions involving bicycles equipped with child seats through experiments. First, fall tests were conducted to evaluate the effect of the integrated head restraints (also commonly known as headrests) of child seats. It was confirmed that head restraints can reduce the impact of head collisions with the road surface. Second, side collision tests were conducted between a car and a bicycle equipped with a child seat, and the effects of the seat belt and head restraint of the child seat were investigated. It was shown that the kinematic behavior of the child dummy significantly was changed depending on wearing the seat belt. In the condition that the seat belt was not fastened, the child dummy was ejected out of the child seat while rotating toward the hood after the impact with the front of the car. In contrast, when the seat belt was fastened, the child dummy was restrained in the child seat and moved together with the bicycle from the start of the collision until the complete stop. Thus, it was found that using child seats with head restraints and using seat belts can reduce the risk of injury to children during an impact with the road surface, because the child dummy in the tests impacted the road surface only after the bicycle already had contact with the road surface.