Abstract: A method of calibrating a video image to the scene imaged is provided for which a vehicle image transit can be associated with the transit of the real-world vehicle. A path is determined by a tracking point for at least one vehicle image. A measuring vehicle image is selected, wherein the measuring vehicle image is associated with a known dimension of the real-world measuring vehicle. At a point on the path, collocated with the tracking point, a scaling factor is determined such that a measuring vehicle image dimension is associated with a real-world dimension. A number of scaling factors can then be assembled into a scaling map allowing vehicles traversing the video scene to be measured in time, by the video frame rate, and distance, by the distance of their images and scaled according to the scaling map. Other embodiments are also disclosed.