This study examines a personal computer system for automatic measurement of the traffic flow, vehicle traveling velocity, and traveling tracks, as well as identification of types of vehicle, on the basis of the image of road traffic that is videotaped by a video camera mounted on an airship type balloon. Since observation is made almost right above the observation point in this traffic flow monitor system, the influence of occlusion due to the vehicle shape is small, and simplification of measurement processing is possible. In that case, the shaking of the airship type balloon causes shaking of the video image. In order to eliminate such an influence, a method to automatically pursue ground control points in order to find the movement of the background so as to cancel the apparent movement was adopted. In the meantime, a vehicle detection/extraction function is necessary for automation of the traffic flow monitor system. As a method to detect and extract a vehicle by means of comparison between the movement of the background and the inclination of the time-space images was adopted in this study. For verification of the measuring accuracy of a series of sequential image analysis methods, experiments were conducted with the help of test vehicles, and data obtained by the sequential image analysis method were compared with actually measured values. As a result, it was found that automatic measurement of the traffic flow, vehicle traveling velocity, and traveling tracks, as well as identification of types of vehicles, would be possible with practical accuracy.