These principles assist in achieving energy conservation and also provide superior lighting quality to users. Glare greatly detracts from nighttime visibility. If two parking lots are equally illuminated to 5 footcandles, the installation with the least glare from the fixtures will provide the greatest visibility, safety, and visual comfort. Unfortunately, numerical levels for glare are not included in exterior lighting standards. At these high angles light produces significant glare, light pollution, and energy waste.
New fixtures allow designers to control where light falls.
By eliminating light spillage into surrounding areas, lower wattage lamps can be used. For example, a driver traveling in rural areas will temporarily be blinded by suddenly encountering bright roadway lights. In driveways, place the first few lights at lower levels to counter this problem. Use HID lamps with specific orientations rather than universal position lamps. Locations requiring low levels of light that are as close as 50 ft.