If an automobile happens to crash into the back of another vehicle while travelling at high speeds, both vehicles will be seriously damaged. Consequently, it is not easy to reconstruct the initial collision state between the two vehicles or determine whether or not the risk perception of the driver is normal. The entire picture of the accident cannot be fully understood and thus clarifying the relevant legal responsibility is difficult. The trace evidence of tires, such as pattern, direction, and impression examination as well as other characteristics, can be carefully observed and used as evidence in accident reconstruction. A case report of a fatal collision involving a bus crashing into the frame of a full trailer on a freeway is examined in this study. The police agency used the characteristics of the trace evidence of the bus tires to reconstruct the initial collision state of the two vehicles to clarify the cause of the accident, and these determination guidelines can be used by police while handling similar cases in the future. This case uses new information regarding the initial collision state of road traffic accidents for reconstruction and provides knowledge and interest for the forensic community.