1. A system for assisting an operator while backing into a given parking site a self-propelled transporter having a forwardly facing operator's station from which the operator's vision directly to the rear of the transporter is blocked by part of the transporter; a closed circuit video system including rearwardly directed camera means at the rear of the transporter for viewing the zone immediately to the rear of the transporter otherwise blocked from the operator's vision, and a viewing montior at the operator's station operatively connected to the camera means; distance indicating means for visually indicating at the operator's station, as the transporter is being backed into a parking site, the decreasing distance from the transporter to the rear end of the parking site; a backing target having a preselected dimensional parameter for placing at the parking site to be viewed by the camera as the transporter is backed toward the parking site; and legend means coupled to said viewing monitor in said video system for providing an indication at said monitor, as the transporter approaches said target while being backed, of the decreasing distance from the transporter to the backing target by utilizing the correspondingly increasing size of the preselected dimensional parameter of the backing target image appearing at the monitor.