Exterior lighting proposed for any site shall be planned, erected and maintained so that the light is confined to the property and will not cast direct light or glare upon properties in adjacent residential zones or upon public roads. Under no circumstances shall light levels at lot lines adjacent to residential zones or at public road lines exceed 0.6 footcandle, measured at ground level. No light source shall be higher than 20 feet other than motion-activated security lights which are normally turned off. Such motion-activated lights shall be no higher than the roofline of buildings on the site. Parking area lighting shall be minimized and shall not exceed one footcandle, measured at ground level, except upon approval of the Planning Board.