When a map screen is displayed in a navigation system of a subject vehicle, a position of any other vehicle is estimated and is displayed in the map screen. Influence of delay due to the following is eliminated or reduced: time consumed in processing in a navigation system of the other vehicle; time consumed in communication between the navigation system of the other vehicle and the navigation system of the subject vehicle; time from when the navigation system of the subject vehicle receives communication information to when it generates information to be notified; and the like. In cases where the influence of delay is taken into account, as mentioned above, accuracy of a notified position of the other vehicle is enhanced. Thus, an accurate operation support system is provided to minimize occurrence of errors.