Day and Night Intensities of Rear Signal System Lights

摘要

Field experiments were conducted to determine the disability glare produced by rear signal system lights at night, the daytime visibility of lights, and the degradation of daytime visibility caused by specularly reflecting surfaces near the lights. A maximum intensity of 300 candelas of red light is indicated by results of the night tests. Daytime tests strongly indicate that specularly reflecting surfaces should be prohibited in the immediate surround of signal lights. Integration of the test results, literature, data on atmospheric effects, and current standards suggests that taillight intensities should be no less than 10 candelas and no more than 30 candelas; brake and turn signals should be 100 to 300 candelas. These suggestions assume that no specularly reflecting surfaces are permitted in the immediate surround of light. (Author)