Pedestrian Visibility Under Automobile Low-Beam Headlight Illumination: With and Without Headlight Covers

Pedestrians and bicyclists are the most vulnerable of all participants in traffic. Their safety at night should be a priority for headlamp designers, rule-making agencies, and consumers alike. A disturbing trend—the use of very dark aftermarket headlamp covers on vehicle headlamps—is emerging. This trend is observed primarily in sports cars owned by young drivers. These dark headlamp covers, often referred to as blackouts, serve no real purpose other than that of supposedly enhancing vehicle appearance. For a driver using such headlamp covers at night, it may appear as though the overall visibility is not much affected. However, this perception is misleading and wrong, as will be clearly demonstrated. The objective was to quantify the detrimental effects dark headlamp covers have on pedestrian visibility. To do so, detection distances were obtained in the field using 15 observers who were approaching stationary pedestrian mockups. The independent variables were pedestrian size (child, adult), diffuse clothing reflectance (dark, light), and illumination (with and without headlamp covers). Clothing reflectance turned out to have the strongest effect on the detection distance, closely followed by the factor of illumination. The conclusions that can be drawn from the work presented are simple. Nighttime pedestrians should not wear dark clothing, instead they should wear white or reflective clothing, and motorists should not drive with dark headlamp covers at night.