There are two ways to reduce the damage caused by traffic accidents: preventive safety and crash safety. In the case of crash safety, data obtained from crash tests are important. This paper reports on crash tests on children's bicycles, a priority issue in traffic accident prevention, and the findings on head injuries in traffic accidents. The position of the head in contact with the vehicle influences the cyclist's injury in a collision with a car. When a bicycle collides with the edge of a car, the cyclist's head makes contact with a highly rigid member. This causes serious injury to the cyclist. If the cyclist's head makes contact with the center of the hood, which is easily deformed, the direct blow to the head is less damaging. However, the rotation of the head during a collision with a car may result in brain damage. In order to consider traffic injuries, it is important to evaluate multiple indicators rather than just one.
