Pedestrian visibility at night: The effect of solid state streetlights

Abstract

This study examines the effect of different types of lamps on pedestrian night time visibility. Detection distance was used as a measure of visibility. The detection distance was measured in the presence and in the absence of on-coming car headlamps in an unlit street. Subsequently, the street was lit using metal halide, high-pressure sodium or LED luminaires. A pedestrian who changed his clothing colour randomly was used as a target. The results showed that the detection distance on the unlit road was 52% shorter in the presence of on coming car headlamps than when the oncoming car headlamps were off. A person wearing black clothing was harder to see and their mean detection distance was 60% less than when the observer was not dazzled by the oncoming car headlights. When the street was lit, the detection distance was doubled. The mean detection distance using LED lamps was statistically similar to that obtained using metal halide lamps, both of which were better than the detection distance obtained under high pressure sodium lighting.

Measuring urban nighttime vitality and its relationship with urban spatial structure: A data-driven approach

“…Time, as an important characteristic of the urban vitality, should be as important as space (Xia et al, 2021). A series of empirical studies show that nighttime vitality can’t be generalized by daytimes for the specificities in psychological and emotional factors and environmental factors (Edensor 2015; Morris 2011; Saraiji et al, 2016). The aggregations and movements of the population during the daytime are mainly affected by commuting, daytime vitality is more stable and easier to recognize (Lin and De Meulder 2012).…”

Road lighting research for drivers and pedestrians: The basis of luminance and illuminance recommendations

“…115,126,183 One benefit of road lighting for pedestrian detection is that it can offset the reduction in detection distance brought about by glare from the headlamps of on-coming vehicles. 184 Regarding the amount of light needed to detect pedestrians, some evidence may be gained by considering lighting at pedestrian crossings. There is however no agreement as to the optimum light level for pedestrian crossings nor where to measure it.…”

“…115,126,183 One benefit of road lighting for pedestrian detection is that it can offset the reduction in detection distance brought about by glare from the headlamps of on-coming vehicles. 184…”