The necessity of the emergency avoidance assistance is determined. In a case where the emergency avoidance assistance is determined to be necessary, emergency avoidance assistance is implemented, and in a case where the emergency avoidance assistance is determined not to be necessary, the prediction assistance is implemented. According to this configuration, it is possible to perform the assistance according to emergency level of the collision. When it is the time of emergency state, it is possible to avoid (decrease) the collision without delaying the assistance, and when it is not the time of emergency state, it is possible to avoid the future collision in advance by the highly accurate prediction.