An exposition of a road lighting model to facilitate simple estimation of road surface illuminance parameters for conventional system specifications and recommendations for retrofitting of luminaires

Optimization of freeform LED roadway lighting complying CIE standards

“…Considering road lighting design, however, not only the illuminance is of interest, but the luminance and luminance uniformity perceived by the driver of the vehicle is of key importance, which is dependent on the roadway composition and is significantly increasing the design complexity. In addition, an ongoing trend towards sustainable lighting can be observed, requiring efficient road lighting design algorithms optimizing towards eco-friendly designs 1 . Road lighting is generally emitting a batwing type illumination distribution 2 , of which the optimal illumination pattern for each road configuration is typically calculated by using analytical procedures, using reduced luminance coefficients, after which the design and optimization of the freeform surfaces is performed based on, for example, ray mapping or feedback functions 3,4 .…”

The effects of lamp types and surface reflectance combinations on the subjective perception of a simulated lit hospital ward environment

“…Thus, with an overview of the preceding literature, this work, undertaken in a ward in a tertiary care hospital setting in Eastern India, conducted a study that examined the existing artificial illumination system, created a series of software-based lighting retrofit simulation models with LED luminaires for 16 different room surface reflectance combinations, analyzed the photometric outputs obtained from simulation and organized a survey with a formulated questionnaire involving 48 subjects regarding subjective discernment of the resultant retrofitted lighting conditions emanating from the variations in lamp types and room surface reflectance values. LED luminaires were chosen for this work as LED technology is widely used for both indoor (Sinnadurai et al , 2012; Wang et al , 2017) and outdoor lighting purposes, including vehicular lighting, area lighting, road lighting simulation and analysis (Khan et al , 2015; Bhattacharya et al , 2021; Roy et al , 2022). LED luminaires are more energy-efficient compared to fluorescent light generation technology, highly conducive to different visual tasks, may not adversely affect body rhythm and health (van Bommel, 2011) and are generally considered to be highly suited for indoor lighting applications (Tsuei et al , 2008; Bhattcharjee and Mazumdar, 2016; Amelkina et al , 2018).…”